This manual is for GNU Gnulib (updated 1970-01-01 00:00:01), which is a library of common routines intended to be shared at the source level.
Copyright © 2004–2023 Free Software Foundation, Inc.
Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.3 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license is included in the section entitled “GNU Free Documentation License”.
gettextize
and autopoint
usersFD_CLR
FD_ISSET
FD_SET
FD_ZERO
_Exit
_exit
_longjmp
_setjmp
_tolower
_toupper
a64l
abort
abs
accept
access
acos
acosf
acosh
acoshf
acoshl
acosl
aio_cancel
aio_error
aio_fsync
aio_read
aio_return
aio_suspend
aio_write
alarm
aligned_alloc
alphasort
asctime
asctime_r
asin
asinf
asinh
asinhf
asinhl
asinl
assert
atan
atan2
atan2f
atan2l
atanf
atanh
atanhf
atanhl
atanl
atexit
atof
atoi
atol
atoll
basename
bind
bsearch
btowc
c8rtomb
c16rtomb
c32rtomb
cabs
cabsf
cabsl
cacos
cacosf
cacosh
cacoshf
cacoshl
cacosl
calloc
call_once
canonicalize
canonicalizef
canonicalizel
carg
cargf
cargl
casin
casinf
casinh
casinhf
casinhl
casinl
catan
catanf
catanh
catanhf
catanhl
catanl
catclose
catgets
catopen
cbrt
cbrtf
cbrtl
ccos
ccosf
ccosh
ccoshf
ccoshl
ccosl
ceil
ceilf
ceill
cexp
cexpf
cexpl
cfgetispeed
cfgetospeed
cfsetispeed
cfsetospeed
chdir
chmod
chown
cimag
cimagf
cimagl
clearerr
clock
clock_getcpuclockid
clock_getres
clock_gettime
clock_nanosleep
clock_settime
clog
clogf
clogl
close
closedir
closelog
cnd_broadcast
cnd_destroy
cnd_init
cnd_signal
cnd_timedwait
cnd_wait
confstr
conj
conjf
conjl
connect
copysign
copysignf
copysignl
cos
cosf
cosh
coshf
coshl
cosl
cpow
cpowf
cpowl
cproj
cprojf
cprojl
creal
crealf
creall
creat
crypt
csin
csinf
csinh
csinhf
csinhl
csinl
csqrt
csqrtf
csqrtl
ctan
ctanf
ctanh
ctanhf
ctanhl
ctanl
ctermid
ctime
ctime_r
daddl
daylight
dbm_clearerr
dbm_close
dbm_delete
dbm_error
dbm_fetch
dbm_firstkey
dbm_nextkey
dbm_open
dbm_store
ddivl
difftime
dirfd
dirname
div
dlclose
dlerror
dlopen
dlsym
dmull
dprintf
drand48
dsubl
dup
dup2
duplocale
encrypt
endgrent
endhostent
endnetent
endprotoent
endpwent
endservent
endutxent
environ
erand48
erf
erfc
erfcf
erfcl
erff
erfl
errno
execl
execle
execlp
execv
execve
execvp
exit
exp
exp2
exp2f
exp2l
expf
expl
expm1
expm1f
expm1l
fabs
fabsf
fabsl
faccessat
fadd
faddl
fattach
fchdir
fchmod
fchmodat
fchown
fchownat
fclose
fcntl
fdatasync
fdetach
fdim
fdimf
fdiml
fdiv
fdivl
fdopen
fdopendir
feclearexcept
fegetenv
fegetexceptflag
fegetmode
fegetround
feholdexcept
feof
feraiseexcept
ferror
fesetenv
fesetexcept
fesetexceptflag
fesetmode
fesetround
fetestexcept
fetestexceptflag
feupdateenv
fexecve
fflush
ffs
fgetc
fgetpos
fgets
fgetwc
fgetws
fileno
flockfile
floor
floorf
floorl
fma
fmaf
fmal
fmax
fmaxf
fmaxl
fmaxmag
fmaxmagf
fmaxmagl
fmemopen
fmin
fminf
fminl
fminmag
fminmagf
fminmagl
fmod
fmodf
fmodl
fmtmsg
fmul
fmull
fnmatch
fopen
fork
fpathconf
fpclassify
fprintf
fputc
fputs
fputwc
fputws
fread
free
freeaddrinfo
freelocale
freopen
frexp
frexpf
frexpl
fromfp
fromfpf
fromfpl
fromfpx
fromfpxf
fromfpxl
fscanf
fseek
fseeko
fsetpos
fstat
fstatat
fstatvfs
fsub
fsubl
fsync
ftell
ftello
ftok
ftruncate
ftrylockfile
ftw
funlockfile
futimens
fwide
fwprintf
fwrite
fwscanf
gai_strerror
getaddrinfo
getc
getc_unlocked
getchar
getchar_unlocked
getcwd
getdate
getdate_err
getdelim
getegid
getenv
geteuid
getgid
getgrent
getgrgid
getgrgid_r
getgrnam
getgrnam_r
getgroups
gethostent
gethostid
gethostname
getitimer
getline
getlogin
getlogin_r
getmsg
getnameinfo
getnetbyaddr
getnetbyname
getnetent
getopt
getpayload
getpayloadf
getpayloadl
getpeername
getpgid
getpgrp
getpid
getpmsg
getppid
getpriority
getprotobyname
getprotobynumber
getprotoent
getpwent
getpwnam
getpwnam_r
getpwuid
getpwuid_r
getrlimit
getrusage
gets
getservbyname
getservbyport
getservent
getsid
getsockname
getsockopt
getsubopt
gettimeofday
getuid
getutxent
getutxid
getutxline
getwc
getwchar
glob
globfree
gmtime
gmtime_r
grantpt
hcreate
hdestroy
hsearch
htonl
htons
hypot
hypotf
hypotl
iconv
iconv_close
iconv_open
if_freenameindex
if_indextoname
if_nameindex
if_nametoindex
ilogb
ilogbf
ilogbl
imaxabs
imaxdiv
inet_addr
inet_ntoa
inet_ntop
inet_pton
initstate
insque
ioctl
isalnum
isalnum_l
isalpha
isalpha_l
isascii
isastream
isatty
isblank
isblank_l
iscntrl
iscntrl_l
isdigit
isdigit_l
isfinite
isgraph
isgraph_l
isgreater
isgreaterequal
isinf
isless
islessequal
islessgreater
islower
islower_l
isnan
isnormal
isprint
isprint_l
ispunct
ispunct_l
isspace
isspace_l
isunordered
isupper
isupper_l
iswalnum
iswalnum_l
iswalpha
iswalpha_l
iswblank
iswblank_l
iswcntrl
iswcntrl_l
iswctype
iswctype_l
iswdigit
iswdigit_l
iswgraph
iswgraph_l
iswlower
iswlower_l
iswprint
iswprint_l
iswpunct
iswpunct_l
iswspace
iswspace_l
iswupper
iswupper_l
iswxdigit
iswxdigit_l
isxdigit
isxdigit_l
j0
j1
jn
jrand48
kill
killpg
l64a
labs
lchown
lcong48
ldexp
ldexpf
ldexpl
ldiv
lfind
lgamma
lgammaf
lgammal
link
linkat
lio_listio
listen
llabs
lldiv
llogb
llogbf
llogbl
llrint
llrintf
llrintl
llround
llroundf
llroundl
localeconv
localtime
localtime_r
lockf
log
log10
log10f
log10l
log1p
log1pf
log1pl
log2
log2f
log2l
logb
logbf
logbl
logf
logl
longjmp
lrand48
lrint
lrintf
lrintl
lround
lroundf
lroundl
lsearch
lseek
lstat
malloc
mblen
mbrlen
mbrtoc8
mbrtoc16
mbrtoc32
mbrtowc
mbsinit
mbsnrtowcs
mbsrtowcs
mbstowcs
mbtowc
memccpy
memchr
memcmp
memcpy
memmove
memset
memset_explicit
mkdir
mkdirat
mkdtemp
mkfifo
mkfifoat
mknod
mknodat
mkstemp
mktime
mlock
mlockall
mmap
modf
modff
modfl
mprotect
mq_close
mq_getattr
mq_notify
mq_open
mq_receive
mq_send
mq_setattr
mq_timedreceive
mq_timedsend
mq_unlink
mrand48
msgctl
msgget
msgrcv
msgsnd
msync
mtx_destroy
mtx_init
mtx_lock
mtx_timedlock
mtx_trylock
mtx_unlock
munlock
munlockall
munmap
nan
nanf
nanl
nanosleep
nearbyint
nearbyintf
nearbyintl
newlocale
nextafter
nextafterf
nextafterl
nextdown
nextdownf
nextdownl
nexttoward
nexttowardf
nexttowardl
nextup
nextupf
nextupl
nftw
nice
nl_langinfo
nl_langinfo_l
nrand48
ntohl
ntohs
open
openat
opendir
openlog
open_memstream
open_wmemstream
optarg
opterr
optind
optopt
pathconf
pause
pclose
perror
pipe
poll
popen
posix_fadvise
posix_fallocate
posix_madvise
posix_mem_offset
posix_memalign
posix_openpt
posix_spawn
posix_spawn_file_actions_addclose
posix_spawn_file_actions_adddup2
posix_spawn_file_actions_addopen
posix_spawn_file_actions_destroy
posix_spawn_file_actions_init
posix_spawnattr_destroy
posix_spawnattr_getflags
posix_spawnattr_getpgroup
posix_spawnattr_getschedparam
posix_spawnattr_getschedpolicy
posix_spawnattr_getsigdefault
posix_spawnattr_getsigmask
posix_spawnattr_init
posix_spawnattr_setflags
posix_spawnattr_setpgroup
posix_spawnattr_setschedparam
posix_spawnattr_setschedpolicy
posix_spawnattr_setsigdefault
posix_spawnattr_setsigmask
posix_spawnp
posix_trace_attr_destroy
posix_trace_attr_getclockres
posix_trace_attr_getcreatetime
posix_trace_attr_getgenversion
posix_trace_attr_getinherited
posix_trace_attr_getlogfullpolicy
posix_trace_attr_getlogsize
posix_trace_attr_getmaxdatasize
posix_trace_attr_getmaxsystemeventsize
posix_trace_attr_getmaxusereventsize
posix_trace_attr_getname
posix_trace_attr_getstreamfullpolicy
posix_trace_attr_getstreamsize
posix_trace_attr_init
posix_trace_attr_setinherited
posix_trace_attr_setlogfullpolicy
posix_trace_attr_setlogsize
posix_trace_attr_setmaxdatasize
posix_trace_attr_setname
posix_trace_attr_setstreamfullpolicy
posix_trace_attr_setstreamsize
posix_trace_clear
posix_trace_close
posix_trace_create
posix_trace_create_withlog
posix_trace_event
posix_trace_eventid_equal
posix_trace_eventid_get_name
posix_trace_eventid_open
posix_trace_eventset_add
posix_trace_eventset_del
posix_trace_eventset_empty
posix_trace_eventset_fill
posix_trace_eventset_ismember
posix_trace_eventtypelist_getnext_id
posix_trace_eventtypelist_rewind
posix_trace_flush
posix_trace_get_attr
posix_trace_get_filter
posix_trace_get_status
posix_trace_getnext_event
posix_trace_open
posix_trace_rewind
posix_trace_set_filter
posix_trace_shutdown
posix_trace_start
posix_trace_stop
posix_trace_timedgetnext_event
posix_trace_trid_eventid_open
posix_trace_trygetnext_event
posix_typed_mem_get_info
posix_typed_mem_open
pow
powf
powl
pread
printf
pselect
psiginfo
psignal
pthread_atfork
pthread_attr_destroy
pthread_attr_getdetachstate
pthread_attr_getguardsize
pthread_attr_getinheritsched
pthread_attr_getschedparam
pthread_attr_getschedpolicy
pthread_attr_getscope
pthread_attr_getstack
pthread_attr_getstacksize
pthread_attr_init
pthread_attr_setdetachstate
pthread_attr_setguardsize
pthread_attr_setinheritsched
pthread_attr_setschedparam
pthread_attr_setschedpolicy
pthread_attr_setscope
pthread_attr_setstack
pthread_attr_setstacksize
pthread_barrier_destroy
pthread_barrier_init
pthread_barrier_wait
pthread_barrierattr_destroy
pthread_barrierattr_getpshared
pthread_barrierattr_init
pthread_barrierattr_setpshared
pthread_cancel
pthread_cleanup_pop
pthread_cleanup_push
pthread_cond_broadcast
pthread_cond_destroy
pthread_cond_init
pthread_cond_signal
pthread_cond_timedwait
pthread_cond_wait
pthread_condattr_destroy
pthread_condattr_getclock
pthread_condattr_getpshared
pthread_condattr_init
pthread_condattr_setclock
pthread_condattr_setpshared
pthread_create
pthread_detach
pthread_equal
pthread_exit
pthread_getconcurrency
pthread_getcpuclockid
pthread_getschedparam
pthread_getspecific
pthread_join
pthread_key_create
pthread_key_delete
pthread_kill
pthread_mutex_consistent
pthread_mutex_destroy
pthread_mutex_getprioceiling
pthread_mutex_init
pthread_mutex_lock
pthread_mutex_setprioceiling
pthread_mutex_timedlock
pthread_mutex_trylock
pthread_mutex_unlock
pthread_mutexattr_destroy
pthread_mutexattr_getprioceiling
pthread_mutexattr_getprotocol
pthread_mutexattr_getpshared
pthread_mutexattr_getrobust
pthread_mutexattr_gettype
pthread_mutexattr_init
pthread_mutexattr_setprioceiling
pthread_mutexattr_setprotocol
pthread_mutexattr_setpshared
pthread_mutexattr_setrobust
pthread_mutexattr_settype
pthread_once
pthread_rwlock_destroy
pthread_rwlock_init
pthread_rwlock_rdlock
pthread_rwlock_timedrdlock
pthread_rwlock_timedwrlock
pthread_rwlock_tryrdlock
pthread_rwlock_trywrlock
pthread_rwlock_unlock
pthread_rwlock_wrlock
pthread_rwlockattr_destroy
pthread_rwlockattr_getpshared
pthread_rwlockattr_init
pthread_rwlockattr_setpshared
pthread_self
pthread_setcancelstate
pthread_setcanceltype
pthread_setconcurrency
pthread_setschedparam
pthread_setschedprio
pthread_setspecific
pthread_sigmask
pthread_spin_destroy
pthread_spin_init
pthread_spin_lock
pthread_spin_trylock
pthread_spin_unlock
pthread_testcancel
ptsname
putc
putc_unlocked
putchar
putchar_unlocked
putenv
putmsg
putpmsg
puts
pututxline
putwc
putwchar
pwrite
qsort
quick_exit
raise
rand
rand_r
random
read
readdir
readdir_r
readlink
readlinkat
readv
realloc
realpath
recv
recvfrom
recvmsg
regcomp
regerror
regexec
regfree
remainder
remainderf
remainderl
remove
remque
remquo
remquof
remquol
rename
renameat
rewind
rewinddir
rint
rintf
rintl
rmdir
round
roundeven
roundevenf
roundevenl
roundf
roundl
scalbln
scalblnf
scalblnl
scalbn
scalbnf
scalbnl
scandir
scanf
sched_get_priority_max
sched_get_priority_min
sched_getparam
sched_getscheduler
sched_rr_get_interval
sched_setparam
sched_setscheduler
sched_yield
seed48
seekdir
select
sem_close
sem_destroy
sem_getvalue
sem_init
sem_open
sem_post
sem_timedwait
sem_trywait
sem_unlink
sem_wait
semctl
semget
semop
send
sendmsg
sendto
setbuf
setegid
setenv
seteuid
setgid
setgrent
sethostent
setitimer
setjmp
setkey
setlocale
setlogmask
setnetent
setpayload
setpayloadf
setpayloadl
setpayloadsig
setpayloadsigf
setpayloadsigl
setpgid
setpgrp
setpriority
setprotoent
setpwent
setregid
setreuid
setrlimit
setservent
setsid
setsockopt
setstate
setuid
setutxent
setvbuf
shm_open
shm_unlink
shmat
shmctl
shmdt
shmget
shutdown
sigaction
sigaddset
sigaltstack
sigdelset
sigemptyset
sigfillset
sighold
sigignore
siginterrupt
sigismember
siglongjmp
signal
signbit
signgam
sigpause
sigpending
sigprocmask
sigqueue
sigrelse
sigset
sigsetjmp
sigsuspend
sigtimedwait
sigwait
sigwaitinfo
sin
sinf
sinh
sinhf
sinhl
sinl
sleep
snprintf
sockatmark
socket
socketpair
sprintf
sqrt
sqrtf
sqrtl
srand
srand48
srandom
sscanf
stat
statvfs
stderr
stdin
stdout
stpcpy
stpncpy
strcasecmp
strcasecmp_l
strcat
strchr
strcmp
strcoll
strcoll_l
strcpy
strcspn
strdup
strerror
strerror_l
strerror_r
strfmon
strfmon_l
strfromd
strfromf
strfroml
strftime
strftime_l
strlen
strncasecmp
strncasecmp_l
strncat
strncmp
strncpy
strndup
strnlen
strpbrk
strptime
strrchr
strsignal
strspn
strstr
strtod
strtof
strtoimax
strtok
strtok_r
strtol
strtold
strtoll
strtoul
strtoull
strtoumax
strxfrm
strxfrm_l
swab
swprintf
swscanf
symlink
symlinkat
sync
sysconf
syslog
system
tan
tanf
tanh
tanhf
tanhl
tanl
tcdrain
tcflow
tcflush
tcgetattr
tcgetpgrp
tcgetsid
tcsendbreak
tcsetattr
tcsetpgrp
tdelete
telldir
tempnam
tfind
tgamma
tgammaf
tgammal
thrd_create
thrd_current
thrd_detach
thrd_equal
thrd_exit
thrd_join
thrd_sleep
thrd_yield
time
timegm
timer_create
timer_delete
timer_getoverrun
timer_gettime
timer_settime
times
timespec_getres
timezone
tmpfile
tmpnam
toascii
tolower
tolower_l
totalorder
totalorderf
totalorderl
totalordermag
totalordermagf
totalordermagl
toupper
toupper_l
towctrans
towctrans_l
towlower
towlower_l
towupper
towupper_l
trunc
truncate
truncf
truncl
tsearch
tss_create
tss_delete
tss_get
tss_set
ttyname
ttyname_r
twalk
tzname
tzset
ufromfp
ufromfpf
ufromfpl
ufromfpx
ufromfpxf
ufromfpxl
ulimit
umask
uname
ungetc
ungetwc
unlink
unlinkat
unlockpt
unsetenv
uselocale
utime
utimensat
utimes
va_arg
va_copy
va_end
va_start
vdprintf
vfprintf
vfscanf
vfwprintf
vfwscanf
vprintf
vscanf
vsnprintf
vsprintf
vsscanf
vswprintf
vswscanf
vwprintf
vwscanf
wait
waitid
waitpid
wcpcpy
wcpncpy
wcrtomb
wcscasecmp
wcscasecmp_l
wcscat
wcschr
wcscmp
wcscoll
wcscoll_l
wcscpy
wcscspn
wcsdup
wcsftime
wcslen
wcsncasecmp
wcsncasecmp_l
wcsncat
wcsncmp
wcsncpy
wcsnlen
wcsnrtombs
wcspbrk
wcsrchr
wcsrtombs
wcsspn
wcsstr
wcstod
wcstof
wcstoimax
wcstok
wcstol
wcstold
wcstoll
wcstombs
wcstoul
wcstoull
wcstoumax
wcswidth
wcsxfrm
wcsxfrm_l
wctob
wctomb
wctrans
wctrans_l
wctype
wctype_l
wcwidth
wmemchr
wmemcmp
wmemcpy
wmemmove
wmemset
wordexp
wordfree
wprintf
write
writev
wscanf
y0
y1
yn
bcmp
bcopy
bsd_signal
bzero
ecvt
fcvt
ftime
gcvt
getcontext
gethostbyaddr
gethostbyname
getwd
h_errno
index
makecontext
mktemp
pthread_attr_getstackaddr
pthread_attr_setstackaddr
rindex
scalb
setcontext
swapcontext
ualarm
usleep
vfork
wcswcs
<aio.h>
<aliases.h>
<argp.h>
<argz.h>
<arpa/inet.h>
<byteswap.h>
<complex.h>
<ctype.h>
<dirent.h>
<dlfcn.h>
<envz.h>
<err.h>
<errno.h>
<error.h>
<execinfo.h>
<fcntl.h>
<fenv.h>
<fmtmsg.h>
<fstab.h>
<fts.h>
<getopt.h>
<glob.h>
<gnu/libc-version.h>
<grp.h>
<gshadow.h>
<ifaddrs.h>
<libintl.h>
<link.h>
<malloc.h>
<math.h>
drem
dremf
dreml
exp10
exp10f
exp10l
finite
finitef
finitel
gamma
gammaf
gammal
isinff
isinfl
isnanf
isnanl
j0f
j0l
j1f
j1l
jnf
jnl
lgamma_r
lgammaf_r
lgammal_r
matherr
pow10
pow10f
pow10l
scalbf
scalbl
significand
significandf
significandl
sincos
sincosf
sincosl
y0f
y0l
y1f
y1l
ynf
ynl
<mcheck.h>
<mntent.h>
<netdb.h>
endnetgrent
gethostbyaddr_r
gethostbyname2
gethostbyname2_r
gethostbyname_r
gethostent_r
getnetbyaddr_r
getnetbyname_r
getnetent_r
getnetgrent
getnetgrent_r
getprotobyname_r
getprotobynumber_r
getprotoent_r
getservbyname_r
getservbyport_r
getservent_r
herror
hstrerror
innetgr
rcmd
rcmd_af
rexec
rexec_af
rresvport
rresvport_af
ruserok
ruserok_af
setnetgrent
<netinet/ether.h>
<netinet/in.h>
bindresvport
getipv4sourcefilter
getsourcefilter
in6addr_any
in6addr_loopback
inet6_option_alloc
inet6_option_append
inet6_option_find
inet6_option_init
inet6_option_next
inet6_option_space
inet6_opt_append
inet6_opt_find
inet6_opt_finish
inet6_opt_get_val
inet6_opt_init
inet6_opt_next
inet6_opt_set_val
inet6_rth_add
inet6_rth_getaddr
inet6_rth_init
inet6_rth_reverse
inet6_rth_segments
inet6_rth_space
setipv4sourcefilter
setsourcefilter
<obstack.h>
<poll.h>
<printf.h>
<pthread.h>
pthread_attr_getaffinity_np
pthread_attr_setaffinity_np
pthread_attr_getsigmask_np
pthread_attr_setsigmask_np
pthread_clockjoin_np
pthread_cond_clockwait
pthread_getaffinity_np
pthread_getattr_default_np
pthread_getattr_np
pthread_getname_np
pthread_kill_other_threads_np
pthread_mutex_clocklock
pthread_rwlock_clockrdlock
pthread_rwlock_clockwrlock
pthread_rwlockattr_getkind_np
pthread_rwlockattr_setkind_np
pthread_setaffinity_np
pthread_setattr_default_np
pthread_setname_np
pthread_sigqueue
pthread_timedjoin_np
pthread_tryjoin_np
<pty.h>
<pwd.h>
<regex.h>
<regexp.h>
<resolv.h>
dn_comp
dn_expand
dn_skipname
res_dnok
res_hnok
res_init
res_mailok
res_mkquery
res_nmkquery
res_nquery
res_nquerydomain
res_nsearch
res_nsend
res_ownok
res_query
res_querydomain
res_search
res_send
<rpc/auth.h>
authdes_create
authdes_pk_create
authnone_create
authunix_create
authunix_create_default
getnetname
host2netname
key_decryptsession
key_decryptsession_pk
key_encryptsession
key_encryptsession_pk
key_gendes
key_get_conv
key_secretkey_is_set
key_setsecret
netname2host
netname2user
user2netname
xdr_des_block
xdr_opaque_auth
<rpc/auth_des.h>
<rpc/auth_unix.h>
<rpc/clnt.h>
callrpc
clnt_create
clnt_pcreateerror
clnt_perrno
clnt_perror
clnt_spcreateerror
clnt_sperrno
clnt_sperror
clntraw_create
clnttcp_create
clntudp_bufcreate
clntudp_create
clntunix_create
get_myaddress
getrpcport
rpc_createerr
<rpc/key_prot.h>
<rpc/netdb.h>
<rpc/pmap_clnt.h>
<rpc/pmap_prot.h>
<rpc/pmap_rmt.h>
<rpc/rpc_msg.h>
<rpc/svc.h>
svc_exit
svc_fdset
svc_getreq
svc_getreq_common
svc_getreq_poll
svc_getreqset
svc_max_pollfd
svc_pollfd
svc_register
svc_run
svc_sendreply
svc_unregister
svcerr_auth
svcerr_decode
svcerr_noproc
svcerr_noprog
svcerr_progvers
svcerr_systemerr
svcerr_weakauth
svcraw_create
svctcp_create
svcudp_bufcreate
svcudp_create
svcunix_create
xprt_register
xprt_unregister
<rpc/xdr.h>
xdr_array
xdr_bool
xdr_bytes
xdr_char
xdr_double
xdr_enum
xdr_float
xdr_free
xdr_hyper
xdr_int
xdr_int16_t
xdr_int32_t
xdr_int64_t
xdr_int8_t
xdr_long
xdr_longlong_t
xdr_netobj
xdr_opaque
xdr_pointer
xdr_quad_t
xdr_reference
xdr_short
xdr_sizeof
xdr_string
xdr_u_char
xdr_u_hyper
xdr_u_int
xdr_u_long
xdr_u_longlong_t
xdr_u_quad_t
xdr_u_short
xdr_uint16_t
xdr_uint32_t
xdr_uint64_t
xdr_uint8_t
xdr_union
xdr_vector
xdr_void
xdr_wrapstring
xdrmem_create
xdrrec_create
xdrrec_endofrecord
xdrrec_eof
xdrrec_skiprecord
xdrstdio_create
<rpcsvc/nislib.h>
nis_add
nis_add_entry
nis_addmember
nis_checkpoint
nis_clone_object
nis_creategroup
nis_destroy_object
nis_destroygroup
nis_dir_cmp
nis_domain_of
nis_domain_of_r
nis_first_entry
nis_freenames
nis_freeresult
nis_freeservlist
nis_freetags
nis_getnames
nis_getservlist
nis_ismember
nis_leaf_of
nis_leaf_of_r
nis_lerror
nis_list
nis_local_directory
nis_local_group
nis_local_host
nis_local_principal
nis_lookup
nis_mkdir
nis_modify
nis_modify_entry
nis_name_of
nis_name_of_r
nis_next_entry
nis_perror
nis_ping
nis_print_directory
nis_print_entry
nis_print_group
nis_print_group_entry
nis_print_link
nis_print_object
nis_print_result
nis_print_rights
nis_print_table
nis_remove
nis_remove_entry
nis_removemember
nis_rmdir
nis_servstate
nis_sperrno
nis_sperror
nis_sperror_r
nis_stats
nis_verifygroup
<rpcsvc/nis_callback.h>
<rpcsvc/yp.h>
xdr_domainname
xdr_keydat
xdr_valdat
xdr_ypbind_resptype
xdr_ypmap_parms
xdr_ypmaplist
xdr_yppushresp_xfr
xdr_ypreq_key
xdr_ypreq_nokey
xdr_ypreq_xfr
xdr_ypresp_all
xdr_ypresp_key_val
xdr_ypresp_maplist
xdr_ypresp_master
xdr_ypresp_order
xdr_ypresp_val
xdr_ypresp_xfr
xdr_ypstat
xdr_ypxfrstat
<rpcsvc/ypclnt.h>
<sched.h>
<search.h>
<selinux/selinux.h>
<semaphore.h>
<shadow.h>
<signal.h>
<spawn.h>
<stdio.h>
asprintf
cuserid
clearerr_unlocked
fcloseall
feof_unlocked
ferror_unlocked
fflush_unlocked
fgetc_unlocked
fgets_unlocked
fileno_unlocked
fopencookie
fputc_unlocked
fputs_unlocked
fread_unlocked
fwrite_unlocked
getw
putw
renameat2
setbuffer
setlinebuf
sys_errlist
sys_nerr
tmpnam_r
vasprintf
<stdlib.h>
canonicalize_file_name
cfree
clearenv
drand48_r
ecvt_r
erand48_r
fcvt_r
getloadavg
getpt
initstate_r
jrand48_r
lcong48_r
lrand48_r
mkostemp
mkostemps
mkstemps
mrand48_r
nrand48_r
on_exit
ptsname_r
qecvt
qecvt_r
qfcvt
qfcvt_r
qgcvt
qsort_r
random_r
rpmatch
secure_getenv
seed48_r
setstate_r
srand48_r
srandom_r
strtod_l
strtof_l
strtol_l
strtold_l
strtoll_l
strtoq
strtoul_l
strtoull_l
strtouq
valloc
<string.h>
explicit_bzero
ffsl
ffsll
memfrob
memmem
mempcpy
memrchr
rawmemchr
sigabbrev_np
sigdescr_np
strcasestr
strchrnul
strerrordesc_np
strerrorname_np
strfry
strsep
strverscmp
<sys/auxv.h>
<sys/capability.h>
<sys/epoll.h>
<sys/eventfd.h>
<sys/fanotify.h>
<sys/file.h>
<sys/fsuid.h>
<sys/gmon.h>
<sys/inotify.h>
<sys/io.h>
, <sys/perm.h>
<sys/kdaemon.h>
<sys/klog.h>
<sys/mman.h>
<sys/mount.h>
<sys/personality.h>
<sys/prctl.h>
<sys/profil.h>
<sys/ptrace.h>
<sys/quota.h>
<sys/random.h>
<sys/reboot.h>
<sys/resource.h>
<sys/sem.h>
<sys/sendfile.h>
<sys/signalfd.h>
<sys/single_threaded.h>
<sys/socket.h>
<sys/stat.h>
<sys/statfs.h>
<sys/swap.h>
<sys/sysctl.h>
<sys/sysinfo.h>
<sys/syslog.h>
<sys/sysmacros.h>
<sys/time.h>
<sys/timerfd.h>
<sys/timex.h>
<sys/uio.h>
<sys/ustat.h>
<sys/vlimit.h>
<sys/wait.h>
<sys/xattr.h>
<termios.h>
<time.h>
<ttyent.h>
<unistd.h>
_Fork
acct
brk
chroot
closefrom
copy_file_range
daemon
dup3
eaccess
endusershell
euidaccess
execveat
execvpe
get_current_dir_name
getdomainname
getdtablesize
getpagesize
getpass
getresgid
getresuid
gettid
getusershell
group_member
pipe2
profil
revoke
sbrk
setlogin
setdomainname
sethostid
sethostname
setresgid
setresuid
setusershell
syncfs
syscall
ttyslot
vhangup
<utmp.h>
<utmpx.h>
<wchar.h>
fgetwc_unlocked
fgetws_unlocked
fputwc_unlocked
fputws_unlocked
getwc_unlocked
getwchar_unlocked
putwc_unlocked
putwchar_unlocked
wcschrnul
wcsftime_l
wcstod_l
wcstof_l
wcstol_l
wcstold_l
wcstoll_l
wcstoq
wcstoul_l
wcstoull_l
wcstouq
wmempcpy
.
)|
or \|
)[
… ]
and [^
… ]
)
(
… )
or \(
… \)
)Gnulib is a source code library that provides basic functionality to programs and libraries. Many software packages make use of Gnulib to avoid reinventing the portability wheel.
Resources:
While portability across operating systems is not one of GNU’s primary goals, it has helped introduce many people to the GNU system, and is worthwhile when it can be achieved at a low cost. This collection helps lower that cost.
Gnulib is intended to be the canonical source for most of the important “portability” and/or common files for GNU projects. These are files intended to be shared at the source level; Gnulib is not a typical library meant to be installed and linked against. Thus, unlike most projects, Gnulib does not normally generate a source tarball distribution; instead, developers grab modules directly from the source repository.
The easiest, and recommended, way to do this is to use the
gnulib-tool
script. Since there is no installation
procedure for Gnulib, gnulib-tool
needs to be run directly
in the directory that contains the Gnulib source code. You can do
this either by specifying the absolute filename of
gnulib-tool
, or by using a symbolic link from a place inside
your PATH
to the gnulib-tool
file of your preferred
Gnulib checkout. For example:
$ ln -s $HOME/gnu/src/gnulib.git/gnulib-tool $HOME/bin/gnulib-tool
Gnulib is available for anonymous checkout. In any Bourne-shell the following should work:
$ git clone https://git.savannah.gnu.org/git/gnulib.git
For a read-write checkout you need to have a login on ‘savannah.gnu.org’ and be a member of the Gnulib project at https://savannah.gnu.org/projects/gnulib. Then, instead of the URL https://git.savannah.gnu.org/git/gnulib.git, use the URL ‘ssh://user@git.savannah.gnu.org/srv/git/gnulib’ where user is your login name on savannah.gnu.org.
git resources:
When you use git annotate
or git blame
with Gnulib, it’s
recommended that you use the -w option, in order to ignore
massive whitespace changes that happened in 2009.
The best way to work with Gnulib is to check it out of git.
To synchronize, you can use git pull
.
Subscribing to the bug-gnulib@gnu.org mailing list will help you to plan when to update your local copy of Gnulib (which you use to maintain your software) from git. You can review the archives, subscribe, etc., via https://lists.gnu.org/mailman/listinfo/bug-gnulib.
Sometimes, using an updated version of Gnulib will require you to use newer versions of GNU Automake or Autoconf. You may find it helpful to join the autotools-announce mailing list to be advised of such changes.
All software here is copyrighted by the Free Software Foundation—you need to have filled out an assignment form for a project that uses the module for that contribution to be accepted here.
If you have a piece of code that you would like to contribute, please email bug-gnulib@gnu.org.
Generally we are looking for files that fulfill at least one of the following requirements:
If your functions define completely new but rarely used functionality, you should probably consider packaging it as a separate library.
Gnulib contains code both under GPL and LGPL. Because several packages that use Gnulib are GPL, the files state they are licensed under GPL. However, to support LGPL projects as well, you may use some of the files under LGPL. The “License:” information in the files under modules/ clarifies the real license that applies to the module source.
Keep in mind that if you submit patches to files in Gnulib, you should license them under a compatible license, which means that sometimes the contribution will have to be LGPL, if the original file is available under LGPL via a “License: LGPL” information in the projects’ modules/ file.
We use space-only indentation in nearly all files. This includes all
*.h, *.c, *.y files, except for the regex
module. Makefile and ChangeLog files are excluded, since TAB
characters are part of their format.
In order to tell your editor to produce space-only indentation, you can use these instructions.
;; In Gnulib, indent with spaces everywhere (not TABs). ;; Exceptions: Makefile and ChangeLog modes. (add-hook 'find-file-hook '(lambda () (if (and buffer-file-name (string-match "/gnulib\\>" (buffer-file-name)) (not (string-equal mode-name "Change Log")) (not (string-equal mode-name "Makefile"))) (setq indent-tabs-mode nil))))
" Don't use tabs for indentation. Spaces are nicer to work with. set expandtab
For Makefile and ChangeLog files, compensate for this by adding this to your $HOME/.vim/after/indent/make.vim file, and similarly for your $HOME/.vim/after/indent/changelog.vim file:
" Use tabs for indentation, regardless of the global setting. set noexpandtab
If you use the GNU indent program, pass it the option --no-tabs.
You can test that a module builds correctly with:
$ ./gnulib-tool --create-testdir --dir=/tmp/testdir module1 ... moduleN $ cd /tmp/testdir $ ./configure && make
Other things:
alloca
and fnmatch
modules for how to achieve this. If
for some reason you cannot do this, and you have a .c file that
leads to an empty .o file on some platforms (through some big
#if
around all the code), then ensure that the compilation unit
is not empty after preprocessing. One way to do this is to
#include <stddef.h>
or <stdio.h>
before the big
#if
.
Gnulib code is intended to be portable to a wide variety of platforms, not just GNU platforms. Gnulib typically attempts to support a platform as long as it is still supported by its provider, even if the platform is not the latest version. See Target Platforms.
Many Gnulib modules exist so that applications need not worry about
undesirable variability in implementations. For example, an
application that uses the malloc
module need not worry about
malloc (0)
returning NULL
on some Standard C
platforms; and glob
users need not worry about glob
silently omitting symbolic links to nonexistent files on some
platforms that do not conform to POSIX.
Gnulib code is intended to port without problem to new hosts, e.g.,
hosts conforming to recent C and POSIX standards. Hence Gnulib code
should avoid using constructs that these newer standards no longer
require, without first testing for the presence of these constructs.
For example, because C11 made variable length arrays optional, Gnulib
code should avoid them unless it first uses the vararrays
module to check whether they are supported.
The following subsections discuss some exceptions and caveats to the general Gnulib portability guidelines.
Currently Gnulib assumes at least a freestanding C99 compiler, possibly operating with a C library that predates C99; with time this assumption will likely be strengthened to later versions of the C standard. Old platforms currently supported include AIX 6.1, HP-UX 11i v1 and Solaris 10, though these platforms are rarely tested. Gnulib itself is so old that it contains many fixes for obsolete platforms, fixes that may be removed in the future.
Because of the freestanding C99 assumption, Gnulib code can include
<float.h>
, <limits.h>
, <stdarg.h>
,
<stddef.h>
, and <stdint.h>
unconditionally; <stdbool.h>
is also in the C99 freestanding
list but is obsolescent as of C23. Gnulib code can also assume the existence
of <ctype.h>
, <errno.h>
, <fcntl.h>
,
<locale.h>
, <signal.h>
, <stdio.h>
,
<stdlib.h>
, <string.h>
, and <time.h>
. Similarly,
many modules include <sys/types.h>
even though it’s not even in
C11; that’s OK since <sys/types.h>
has been around nearly
forever.
Even if the include files exist, they may not conform to the C standard.
However, GCC has a fixincludes
script that attempts to fix most
C89-conformance problems. Gnulib currently assumes include files
largely conform to C89 or better. People still using ancient hosts
should use fixincludes or fix their include files manually.
Even if the include files conform, the library itself may not.
For example, strtod
and mktime
have some bugs on some platforms.
You can work around some of these problems by requiring the relevant
modules, e.g., the Gnulib mktime
module supplies a working and
conforming mktime
.
Although the C99 standard specifies many features, Gnulib code is conservative about using them, partly because Gnulib predates the widespread adoption of C99, and partly because many C99 features are not well-supported in practice. C99 features that are reasonably portable nowadays include:
for
statement.
long long int
.
<stdbool.h>
, although Gnulib code no longer uses
it directly, preferring plain bool
via the
stdbool
module instead.
See stdbool.h.
<stdint.h>
, assuming the stdint
module is used.
See stdint.h.
__VA_ARGS__
in MSVC differs from the one
in ISO C 99, see https://stackoverflow.com/questions/5134523/.
But usually this matters only for macros that decompose __VA_ARGS__
.
static inline
functions.
__func__
, assuming the func
module is used. See func.
restrict
qualifier, assuming
AC_REQUIRE([AC_C_RESTRICT])
is used.
This qualifier is sometimes implemented via a macro, so C++ code that
uses Gnulib should avoid using restrict
as an identifier.
flexmember
module).
Gnulib avoids some features even though they are standardized by C99, as they have portability problems in practice. Here is a partial list of avoided C99 features. Many other C99 features are portable only if their corresponding modules are used; Gnulib code that uses such a feature should require the corresponding module.
__STDC_NO_VLA__
is defined.
See the vararrays
and vla
modules.
GNULIB_NO_VLA
or __STDC_NO_VLA__
is defined.
This lets you define GNULIB_NO_VLA
to pacify GCC when
using its -Wvla-larger-than warnings option,
and to avoid large stack usage that may have security implications.
GNULIB_NO_VLA
does not affect Gnulib’s other uses of VLAs and
variably modified types, such as array declarations in function
prototype scope.
extern inline
functions, without checking whether they are
supported. See Extern inline functions.
<iso646.h>
, since GNU programs need not worry about deficient
source-code encodings.
The GNU coding standards allow one departure from strict C: Gnulib
code can assume that standard internal types like
ptrdiff_t
and size_t
are no
wider than long
. POSIX requires implementations to support at
least one programming environment where this is true, and such
environments are recommended for Gnulib-using applications. When it
is easy to port to non-POSIX platforms like MinGW where these types
are wider than long
, new Gnulib code should do so, e.g., by
using ptrdiff_t
instead of long
. However, it is not
always that easy, and no effort has been made to check that all Gnulib
modules work on MinGW-like environments.
Gnulib code makes the following additional assumptions:
int
and unsigned int
are at least 32 bits wide. POSIX
and the GNU coding standards both require this.
Previously, Gnulib code sometimes also assumed that signed integer arithmetic wraps around, but modern compiler optimizations sometimes do not guarantee this, and Gnulib code with this assumption is now considered to be questionable. See Integer Properties.
Although some Gnulib modules contain explicit support for the other signed integer representations allowed by the C standard (ones’ complement and signed magnitude), these modules are the exception rather than the rule. All practical Gnulib targets use two’s complement.
memset (A, 0, sizeof A)
initializes an array A
of
pointers to NULL.
intptr_t
and uintptr_t
exist, and pointers
can be converted to and from these types without loss of information.
ptrdiff_t
or size_t
values, then S + T
cannot overflow.
(char *) &O <= (char *) P && (char *) P <
(char *) (&O + 1)
.
uintptr_t
, except that offsets are
multiplied by the size of the pointed-to objects.
For example, if P + I
is a valid expression involving a pointer
P and an integer I, then (uintptr_t) (P + I) ==
(uintptr_t) ((uintptr_t) P + I * sizeof *P)
.
Similar arithmetic can be done with intptr_t
, although more
care must be taken in case of integer overflow or negative integers.
P
has alignment A
if and only if
(uintptr_t) P % A
is zero, and similarly for intptr_t
.
S + T
cannot overflow.
Overflow in this case would mean that the rest of your program fits
into T bytes, which can’t happen in realistic flat-address-space
hosts.
0 + (char *) NULL == (char *) NULL
.
Some system platforms violate these assumptions and are therefore not Gnulib porting targets. See Unsupported Platforms.
We develop and maintain a testsuite for Gnulib. The goal is to have a 100% firm interface so that maintainers can feel free to update to the code in git at any time and know that their application will not break. This means that before any change can be committed to the repository, a test suite program must be produced that exposes the bug for regression testing.
In Gnulib, we don’t use topic branches for experimental work. Therefore, occasionally a broken commit may be pushed in Gnulib. It does not happen often, but it does happen.
To compensate for this, Gnulib offers “stable branches”. These are branches of the Gnulib code that are maintained over some longer period (a year, for example) and include
config.guess
and config.sub
.
Not included in the stable branches are:
texinfo.tex
,
So far, we have four stable branches:
stable-202307
A stable branch that starts at the beginning of July 2023.
stable-202301
A stable branch that starts at the beginning of January 2023.
stable-202207
A stable branch that starts at the beginning of July 2022. It is no longer updated.
stable-202201
A stable branch that starts at the beginning of January 2022. It is no longer updated.
The two use-cases of stable branches are thus:
When compiling and testing Gnulib and Gnulib-using programs, certain
compiler options can help improve reliability. First of all, make it
a habit to use ‘-Wall’ in all compilation commands. Beyond that,
the manywarnings
module enables several forms of static checking in
GCC and related compilers (see manywarnings).
For dynamic checking, you can run configure
with CFLAGS
options appropriate for your compiler. For example:
./configure \ CPPFLAGS='-Wall'\ CFLAGS='-g3 -O2'\ ' -D_FORTIFY_SOURCE=2'\ ' -fsanitize=undefined'\ ' -fsanitize-undefined-trap-on-error'
Here:
-D_FORTIFY_SOURCE=2
enables extra security hardening checks in
the GNU C library.
-fsanitize=undefined
enables GCC’s undefined behavior sanitizer
(ubsan
), and
-fsanitize-undefined-trap-on-error
causes ubsan
to
abort the program (through an “illegal instruction” signal). This
measure stops exploit attempts and also allows you to debug the issue.
Without the -fsanitize-undefined-trap-on-error
option,
-fsanitize=undefined
causes messages to be printed, and
execution continues after an undefined behavior situation.
The message printing causes GCC-like compilers to arrange for the
program to dynamically link to libraries it might not otherwise need.
With GCC, instead of -fsanitize-undefined-trap-on-error
you can
use the -static-libubsan
option to arrange for two of the extra
libraries (libstdc++
and libubsan
) to be linked
statically rather than dynamically, though this typically bloats the
executable and the remaining extra libraries are still linked
dynamically.
It is also good to occasionally run the programs under valgrind
(see Running self-tests under valgrind).
GNU Gnulib is part of the GNU Operating System, developed by the GNU Project.
If you are the author of an awesome program and want to join us in writing Free (libre) Software, please consider making it an official GNU program and become a GNU Maintainer. Instructions on how to do this are here. We are looking forward to hacking with you!
Don’t have a program to contribute? Look at all the other ways to help.
And to learn more about Free (libre) Software in general, please read and share this page.
Gnulib’s design and development philosophy is organized around steady, collaborative, and open development of reusable modules that are suitable for a reasonably wide variety of platforms.
Gnulib is useful to enhance various aspects of a package:
asprintf
, canonicalize_file_name
are not affected
by buffer sizing problems that affect sprintf
, realpath
.
openat
does not have the race conditions that open
has. Etc.
xalloc
,
xprintf
, xstrtod
, xgetcwd
.
Classical libraries are installed as binary object code. Gnulib is
different: It is used as a source code library. Each package that uses
Gnulib thus ships with part of the Gnulib source code. The used portion
of Gnulib is tailored to the package: A build tool, called
gnulib-tool
, is provided that copies a tailored subset of Gnulib
into the package.
One of the goals of Gnulib is to make portable programming easy, on the basis of the standards relevant for GNU (and Unix). The objective behind that is to avoid a fragmentation of the user community into disjoint user communities according to the operating system, and instead allow synergies between users on different operating systems.
Another goal of Gnulib is to provide application code that can be shared between several applications. Some people wonder: "What? glibc doesn’t have a function to copy a file?" Indeed, the scope of a system’s libc is to implement the relevant standards (ISO C, POSIX) and to provide access functions to the kernel’s system calls, and little more.
There is no clear borderline between both areas.
For example, Gnulib has a facility for generating the name of backup files. While this task is entirely at the application level—no standard specifies an API for it—the naïve code has some portability problems because on some platforms the length of file name components is limited to 30 characters or so. Gnulib handles that.
Similarly, Gnulib has a facility for executing a command in a
subprocess. It is at the same time a portability enhancement (it
works on GNU, Unix, and Windows, compared to the classical
fork
/exec
idiom which is not portable to Windows), as well
as an application aid: it takes care of redirecting stdin and/or
stdout if desired, and emits an error message if the subprocess
failed.
Gnulib supports a number of platforms that we call the “reasonable portability targets”. This class consists of widespread operating systems, for three years after their last availability, or—for proprietary operating systems—as long as the vendor provides commercial support for it. Already existing Gnulib code for older operating systems is usually left in place for longer than these three years. So it comes that programs that use Gnulib run pretty well also on these older operating systems.
Some operating systems are not very widespread, but are Free Software and are actively developed. Such platforms are also supported by Gnulib, if that OS’s developers community keeps in touch with the Gnulib developers, by providing bug reports, analyses, or patches. For such platforms, Gnulib supports only the versions of the last year or the last few months, depending on the maturity of said OS project, the number of its users, and how often these users upgrade.
Niche operating systems are generally unsupported by Gnulib, unless some of their developers or users contribute support to Gnulib.
The degree of support Gnulib guarantees for a platform depends on the amount of testing it gets from volunteers. Platforms on which Gnulib is frequently tested are the best supported. Then come platforms with occasional testing, then platforms which are rarely tested. Usually, we fix bugs when they are reported. Except that some rarely tested platforms are also low priority; bug fixes for these platforms can take longer.
As of 2023, the list of supported platforms is the following:
Note that some modules are currently unsupported on native Windows:
mgetgroups
, getugroups
, idcache
,
userspec
, openpty
, login_tty
, forkpty
,
pt_chown
, grantpt
, pty
, savewd
,
mkancesdirs
, mkdir-p
, euidaccess
, faccessat
.
The versions of Windows that are supported are Windows 10 and newer.
The following platforms were supported in the past, but are no longer supported:
Gnulib supports these operating systems only in an unvirtualized environment.
When you run an OS inside a virtual machine, you have to be aware that the
virtual machine can bring in bugs of its own. For example, floating-point
operations on Solaris can behave slightly differently in QEMU than on real
hardware. And Haiku’s bash
program misbehaves in VirtualBox 3,
whereas it behaves fine in VirtualBox 4.
Similarly, running native Windows binaries on GNU/Linux under WINE is rarely tested and low priority: WINE has a set of behaviours and bugs that is slightly different from native Windows.
Some platforms with C compilers are not supported by Gnulib because the platforms violate Gnulib’s C portability assumptions. See Other portability assumptions made by Gnulib.
These assumptions are not required by the C or POSIX standards but hold on almost all practical porting targets. If you need to port Gnulib code to a platform where these assumptions are not true, we would appreciate hearing of any fixes. We need fixes that do not increase runtime overhead on standard hosts and that are relatively easy to maintain.
These platforms are listed below to illustrate problems that Gnulib and Gnulib-using code would have if it were intended to be portable to all practical POSIX or C platforms.
If you use Clang with -fsanitize=undefined, you can work around the problem by also using ‘-fno-sanitize=pointer-overflow’, although this may also disable some unrelated and useful pointer checks. Perhaps someday the Clang developers will fix the infelicity.
intptr_t
and uintptr_t
, which are optional in the C and
POSIX standards. However, these two types are required for the XSI
extension to POSIX, and many Gnulib modules use them. To work around
this compatibility problem, Gnulib-using applications can be run on
the IBM i’s PASE emulation environment. The IBM i’s architecture
descends from the System/38 (1978).
CHAR_BIT == 9
and INT_MIN == -INT_MAX
. By default
UINT_MAX
is 2^{36} - 2, which does not conform to the C
requirement that it be one less than a power of two. Although
compiler options can raise UINT_MAX
to be 2^{36} - 1,
this can break system code that uses -0 as a flag value.
This platform’s architecture descends from the UNIVAC 1103 (1953).
unsigned int
uses the low-order 40 bits of the word, and
int
uses the low-order 41 bits of the word with a
signed-magnitude representation. On these machines, INT_MAX ==
UINT_MAX
, INT_MIN == -INT_MAX
, and sizeof (int) == 6
.
This platform’s architecture descends from the Burroughs B5000 (1961).
The following platforms are not supported by Gnulib. The cost of supporting them would exceed the benefit because they are rarely used, or poorly documented, or have been supplanted by other platforms, or diverge too much from POSIX, or some combination of these and other factors. Please don’t bother sending us patches for them.
Gnulib is divided into modules. Every module implements a single facility. Modules can depend on other modules.
A module consists of a number of files and a module description. The
files are copied by gnulib-tool
into the package that will use it,
usually verbatim, without changes. Source code files (.h, .c files)
reside in the lib/ subdirectory. Autoconf macro files reside in
the m4/ subdirectory. Build scripts reside in the
build-aux/ subdirectory.
The module description contains the list of files; gnulib-tool
copies these files. It contains the module’s
dependencies; gnulib-tool
installs them as well. It also
contains the autoconf macro invocation (usually a single line or
nothing at all); gnulib-tool
ensures this is invoked from the
package’s configure.ac file. And also a Makefile.am
snippet; gnulib-tool
collects these into a Makefile.am
for the tailored Gnulib part. The module description and include file
specification are for documentation purposes; they are combined into
MODULES.html.
The module system serves two purposes:
getopt_long
function—this is a common way to implement parsing
of command line options in a way that complies with the GNU standards—needs
the source code (lib/getopt.c and others), the autoconf macro
which detects whether the system’s libc already has this function (in
m4/getopt.m4), and a few Makefile.am lines that create the
substitute getopt.h if not. These three pieces belong together.
They cannot be used without each other. The module description and
gnulib-tool
ensure that they are copied altogether into the
destination package.
In other words, the module is the elementary unit of code in Gnulib, comparable to a class in object-oriented languages like Java or C#.
The module system is the basis of gnulib-tool
. When
gnulib-tool
copies a part of Gnulib into a package, it first
compiles a module list, starting with the requested modules and adding all
the dependencies, and then collects the files, configure.ac
snippets and Makefile.am snippets.
There are modules of various kinds in Gnulib. For a complete list of the modules, see in MODULES.html.
When a function is not implemented by a system, the Gnulib module provides an implementation under the same name. Examples are the ‘snprintf’ and ‘readlink’ modules.
Similarly, when a function is not correctly implemented by a system, Gnulib provides a replacement. For functions, we use the pattern
#if !HAVE_WORKING_FOO # define foo rpl_foo #endif
and implement the foo
function under the name rpl_foo
. This
renaming is needed to avoid conflicts at compile time (in case the system
header files declare foo
) and at link/run time (because the code
making use of foo
could end up residing in a shared library, and
the executable program using this library could be defining foo
itself).
For header files, such as stdint.h
, we provide
the substitute only if the system doesn’t provide a correct one. The
template of this replacement is distributed in a slightly different name,
with ‘.in’ inserted before the ‘.h’ extension, so that on
systems which do provide a correct
header file the system’s one is used.
The modules in this category are supported in C++ mode as well. This means, while the autoconfiguration uses the C compiler, the resulting header files and function substitutes can be used with a matching C++ compiler as well.
These are sometimes POSIX functions with GNU extensions also found in glibc—examples: ‘getopt’, ‘fnmatch’—and often new APIs—for example, for all functions that allocate memory in one way or the other, we have variants which also include the error checking against the out-of-memory condition.
Examples are a module for copying a file—the portability problems
relate to the copying of the file’s modification time, access rights,
and extended attributes—or a module for extracting the tail
component of a file name—here the portability to native Windows
requires a different API than the classical POSIX basename
function.
Examples are an error reporting function, a module that allows output of numbers with K/M/G suffixes, or cryptographic facilities.
Examples are data structures like ‘list’, or abstract output stream
classes that work around the fact that an application cannot implement an
stdio FILE
with its logic. Here, while staying in C, we use
implementation techniques like tables of function pointers, known from the
C++ language or from the Linux kernel.
Examples are the ‘iconv’ module, which interfaces to the
iconv
facility, regardless whether it is contained in libc or in
an external libiconv
. Or the ‘readline’ module, which
interfaces to the GNU readline library.
An example is the ‘maintainer-makefile’ module, which provides extra Makefile tags for maintaining a package.
Gnulib is maintained collaboratively. The mailing list is
<bug-gnulib at gnu dot org>
. Be warned that some people on the
list may be very active at some times and unresponsive at other times.
Every module has one or more maintainers. While issues are discussed collaboratively on the list, the maintainer of a module nevertheless has a veto right regarding changes in his module.
All patches should be posted to the list, regardless whether they are proposed patches or whether they are committed immediately by the maintainer of the particular module. The purpose is not only to inform the other users of the module, but mainly to allow peer review. It is not uncommon that several people contribute comments or spot bugs after a patch was proposed.
Conversely, if you are using Gnulib, and a patch is posted that affects one of the modules that your package uses, you have an interest in proofreading the patch.
Most modules are under the GPL. Some, mostly modules which can reasonably be used in libraries, are under LGPL. Few modules are under other licenses, such as LGPLv2+, unlimited, or public domain.
If the module description file says "GPL", it means "GPLv3+" (GPLv3 or newer, at the licensee’s choice); if it says "LGPL", it means "LGPLv3+" (LGPLv3 or newer, at the licensee’s choice).
The source files, more precisely the files in lib/ and build-aux/, are under a license compatible with the module’s license. Most often, they are under the same license. But files can be shared among several modules, and in these cases it can happen that a source file is under a weaker license than noted in the module description – namely under the weakest license among the licenses of the modules that contain the file.
Different licenses apply to files in special directories:
Module description files are under this copyright:
Copyright © 20XX–20YY Free Software Foundation, Inc.
Copying and distribution of this file, with or without modification, in any medium, are permitted without royalty provided the copyright notice and this notice are preserved.
Autoconf macro files are under this copyright:
Copyright © 20XX–20YY Free Software Foundation, Inc.
This file is free software; the Free Software Foundation gives unlimited permission to copy and/or distribute it, with or without modifications, as long as this notice is preserved.
If a license statement is not present in a test module, the test files are under GPL. Even if the corresponding source module is under LGPL, this is not a problem, since compiled tests are not installed by “make install”.
Documentation files are under this copyright:
Copyright © 2004–20YY Free Software Foundation, Inc.
Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.3 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license is at https://www.gnu.org/licenses/fdl-1.3.en.html.
If you want to use some Gnulib modules under LGPL, you can do so by
passing the option ‘--lgpl’ to gnulib-tool
. This will
ensure that all imported modules can be used under the LGPL license.
Similarly, if you want some Gnulib modules
under LGPLv2+ (Lesser GPL version 2.1 or newer), you can do so by
passing the option ‘--lgpl=2’ to gnulib-tool
.
Keep in mind that when you submit patches to files in Gnulib, you should license them under a compatible license. This means that sometimes the contribution will have to be LGPL, if the original file is available under LGPL. You can find out about it by looking at the license header of the file.
Gnulib modules are continually adapted, to match new practices, to be consistent with newly added modules, or simply as a response to build failure reports.
If you are willing to report an occasional regression, we recommend to use the newest version from git always, except in periods of major changes. Most Gnulib users do this.
Gnulib is open in the sense that we gladly accept contributions if they are generally useful, well engineered, and if the contributors have signed the obligatory papers with the FSF.
The module system is open in the sense that a package using Gnulib can
gnulib-tool
.
This is achieved by the ‘--local-dir’ option of gnulib-tool
(see Extending Gnulib).
The gnulib-tool
command is the recommended way to import
Gnulib modules. It is possible to borrow Gnulib modules in a package
without using gnulib-tool
, relying only on the
meta-information stored in the modules/* files, but with a
growing number of modules this becomes tedious. gnulib-tool
simplifies the management of source files, Makefile.ams and
configure.ac in packages incorporating Gnulib modules.
gnulib-tool is not installed in a standard directory that is
contained in the PATH
variable. It needs to be run directly in
the directory that contains the Gnulib source code. You can do this
either by specifying the absolute filename of gnulib-tool, or
you can also use a symbolic link from a place inside your PATH
to the gnulib-tool file of your preferred and most up-to-date
Gnulib checkout, like this:
$ ln -s $HOME/gnu/src/gnulib.git/gnulib-tool $HOME/bin/gnulib-tool
Run ‘gnulib-tool --help’ for information. To get familiar with
gnulib-tool
without affecting your sources, you can also try
some commands with the option ‘--dry-run’; then
gnulib-tool
will only report which actions it would perform in
a real run without changing anything.
gettextize
and autopoint
usersThere are four ways of finding the names of Gnulib modules that you can use in your package:
Gnulib assumes that your project uses Autoconf. When using Gnulib, you will need to have Autoconf among your build tools.
Gnulib also assumes that your project’s configure.ac contains the line
AC_CONFIG_HEADERS([config.h])
The config.h file gets generated with platform dependent C macro definitions, and the source files include it (see Changing your sources for use with Gnulib).
Unless you use gnulib-tool
’s --gnu-make option,
Gnulib also assumes that your project uses Automake at least in a
subdirectory of your project. While the use of Automake in your
project’s top level directory is an easy way to fulfil the Makefile
conventions of the GNU coding standards, Gnulib does not require it.
Invoking ‘gnulib-tool --import’ will copy source files, create a Makefile.am to build them, generate a file gnulib-comp.m4 with Autoconf M4 macro declarations used by configure.ac, and generate a file gnulib-cache.m4 containing the cached specification of how Gnulib is used.
Our example will be a library that uses Autoconf, Automake and
Libtool. It calls strdup
, and you wish to use gnulib to make
the package portable to C99 and C11 (which don’t have strdup
).
~/src/libfoo$ gnulib-tool --import strdup Module list with included dependencies: absolute-header extensions strdup string File list: lib/dummy.c lib/strdup.c lib/string.in.h m4/absolute-header.m4 m4/extensions.m4 m4/gnulib-common.m4 m4/strdup.m4 m4/string_h.m4 Creating directory ./lib Creating directory ./m4 Copying file lib/dummy.c Copying file lib/strdup.c Copying file lib/string.in.h Copying file m4/absolute-header.m4 Copying file m4/extensions.m4 Copying file m4/gnulib-common.m4 Copying file m4/gnulib-tool.m4 Copying file m4/strdup.m4 Copying file m4/string_h.m4 Creating lib/Makefile.am Creating m4/gnulib-cache.m4 Creating m4/gnulib-comp.m4 Finished. You may need to add #include directives for the following .h files. #include <string.h> Don't forget to - add "lib/Makefile" to AC_CONFIG_FILES in ./configure.ac, - mention "lib" in SUBDIRS in Makefile.am, - mention "-I m4" in ACLOCAL_AMFLAGS in Makefile.am, - invoke gl_EARLY in ./configure.ac, right after AC_PROG_CC, - invoke gl_INIT in ./configure.ac. ~/src/libfoo$
By default, the source code is copied into lib/ and the M4
macros in m4/. You can override these paths by using
--source-base=DIRECTORY
and --m4-base=DIRECTORY
. Some
modules also provide other files necessary for building. These files
are copied into the directory specified by ‘AC_CONFIG_AUX_DIR’ in
configure.ac or by the --aux-dir=DIRECTORY
option. If
neither is specified, the current directory is assumed.
gnulib-tool
can make symbolic links instead of copying the
source files. The option to specify for this is ‘--symlink’, or
‘-s’ for short. This can be useful to save a few kilobytes of disk
space. But it is likely to introduce bugs when gnulib
is updated;
it is more reliable to use ‘gnulib-tool --update’ (see below)
to update to newer versions of gnulib
. Furthermore it requires
extra effort to create self-contained tarballs, and it may disturb some
mechanism the maintainer applies to the sources. For these reasons,
this option is generally discouraged.
gnulib-tool
will overwrite any preexisting files, in
particular Makefile.am. It is also possible to separate the
generated Makefile.am content (for building the gnulib library)
into a separate file, say gnulib.mk, that can be included by your
handwritten Makefile.am, but this is a more advanced use of
gnulib-tool
.
Consequently, it is a good idea to choose directories that are not
already used by your projects, to separate gnulib imported files from
your own files. This approach is also useful if you want to avoid
conflicts between other tools (e.g., gettextize
that also copy
M4 files into your package. Simon Josefsson successfully uses a source
base of gl/, and a M4 base of gl/m4/, in several
packages.
After the ‘--import’ option on the command line comes the list of Gnulib modules that you want to incorporate in your package. The names of the modules coincide with the filenames in Gnulib’s modules/ directory.
Some Gnulib modules depend on other Gnulib modules. gnulib-tool
will automatically add the needed modules as well; you need not list
them explicitly. gnulib-tool
will also memorize which dependent
modules it has added, so that when someday a dependency is dropped, the
implicitly added module is dropped as well (unless you have explicitly
requested that module).
If you want to cut a dependency, i.e., not add a module although one of your requested modules depends on it, you may use the option ‘--avoid=module’ to do so. Multiple uses of this option are possible. Of course, you will then need to implement the same interface as the removed module.
A few manual steps are required to finish the initial import.
gnulib-tool
printed a summary of these steps.
First, you must ensure Autoconf can find the macro definitions in
gnulib-comp.m4. Use the ACLOCAL_AMFLAGS
specifier in
your top-level Makefile.am file, as in:
ACLOCAL_AMFLAGS = -I m4
You are now ready to call the M4 macros in gnulib-comp.m4
from
configure.ac. The macro gl_EARLY
must be called as soon
as possible after verifying that the C compiler is working.
Typically, this is immediately after AC_PROG_CC
, as in:
... AC_PROG_CC gl_EARLY ...
The core part of the gnulib checks are done by the macro
gl_INIT
. Place it further down in the file, typically where
you normally check for header files or functions. It must come after
other checks which may affect the compiler invocation, such as
AC_MINIX
. For example:
... # For gnulib. gl_INIT ...
gl_INIT
will in turn call the macros related with the
gnulib functions, be it specific gnulib macros, like gl_FUNC_ALLOCA
or Autoconf or Automake macros like AC_FUNC_ALLOCA
or
AM_FUNC_GETLINE
. So there is no need to call those macros yourself
when you use the corresponding gnulib modules.
You must also make sure that the gnulib library is built. Add the
Makefile
in the gnulib source base directory to
AC_CONFIG_FILES
, as in:
AC_CONFIG_FILES(... lib/Makefile ...)
You must also make sure that make
will recurse into the gnulib
directory. To achieve this, add the gnulib source base directory to a
SUBDIRS
Makefile.am statement, as in:
SUBDIRS = lib
or if you, more likely, already have a few entries in SUBDIRS
,
you can add something like:
SUBDIRS += lib
Finally, you have to add compiler and linker flags in the appropriate source directories, so that you can make use of the gnulib library. Since some modules (‘getopt’, for example) may copy files into the build directory, top_builddir/lib is needed as well as top_srcdir/lib. For example:
... AM_CPPFLAGS = -I$(top_builddir)/lib -I$(top_srcdir)/lib ... LDADD = lib/libgnu.a ...
Don’t forget to #include
the various header files. In this
example, you would need to make sure that ‘#include <string.h>’
is evaluated when compiling all source code files, that want to make
use of strdup
.
In the usual case where Autoconf is creating a config.h file, you should include config.h first, before any other include file. That way, for example, if config.h defines ‘restrict’ to be the empty string on a non-C99 host, or a macro like ‘_FILE_OFFSET_BITS’ that affects the layout of data structures, the definition is consistent for all include files. Also, on some platforms macros like ‘_FILE_OFFSET_BITS’ and ‘_GNU_SOURCE’ may be ineffective, or may have only a limited effect, if defined after the first system header file is included.
Finally, note that you cannot use AC_LIBOBJ
or
AC_REPLACE_FUNCS
in your configure.ac and expect the
resulting object files to be automatically added to lib/libgnu.a.
This is because your AC_LIBOBJ
and AC_REPLACE_FUNCS
invocations
from configure.ac augment a variable @LIBOBJS@
(and/or
@LTLIBOBJS@
if using Libtool), whereas lib/libgnu.a
is built from the contents of a different variable, usually
@gl_LIBOBJS@
(or @gl_LTLIBOBJS@
if using Libtool).
You can at any moment decide to use Gnulib differently than the last time.
There are two ways to change how Gnulib is used. Which one you’ll use,
depends on where you keep track of options and module names that you pass
to gnulib-tool
.
gnulib-tool
again, with modified options and more or fewer module names.
gnulib-tool
remembers which modules were used last time. If you
want to rely on gnulib-tool
’s own memory of the last used
options and module names, you can use the commands
gnulib-tool --add-import
and
gnulib-tool --remove-import
.
So, if you only want to use more Gnulib modules, simply invoke
gnulib-tool --add-import new-modules
. The list of
modules that you pass after ‘--add-import’ is added to the
previous list of modules.
Similarly, if you want to use fewer Gnulib modules, simply invoke
gnulib-tool --remove-import unneeded-modules
. The list
of modules that you pass after ‘--remove-import’ is removed
from the previous list of modules. Note that if a module is then still
needed as dependency of other modules, it will be used nevertheless.
If you want to really not use a module any more, regardless of
whether other modules may need it, you need to use the ‘--avoid’
option.
For other changes, such as different choices of ‘--lib’, ‘--source-base’ or ‘--aux-dir’, the normal way is to modify manually the file gnulib-cache.m4 in the M4 macros directory, then launch ‘gnulib-tool --add-import’.
The only change for which this doesn’t work is a change of the
‘--m4-base’ directory. Because, when you pass a different value of
‘--m4-base’, gnulib-tool
will not find the previous
gnulib-cache.m4 file any more. A possible solution is to
manually copy the gnulib-cache.m4 into the new M4 macro directory.
In the gnulib-cache.m4 file, the macros have the following meaning:
gl_MODULES
The argument is a space separated list of the requested modules, not including dependencies.
gl_AVOID
The argument is a space separated list of modules that should not be used, even if they occur as dependencies. Corresponds to the ‘--avoid’ command line argument.
gl_SOURCE_BASE
The argument is the relative file name of the directory containing the gnulib source files (mostly *.c and *.h files). Corresponds to the ‘--source-base’ command line argument.
gl_M4_BASE
The argument is the relative file name of the directory containing the gnulib M4 macros (*.m4 files). Corresponds to the ‘--m4-base’ command line argument.
gl_TESTS_BASE
The argument is the relative file name of the directory containing the gnulib unit test files. Corresponds to the ‘--tests-base’ command line argument.
gl_LIB
The argument is the name of the library to be created. Corresponds to the ‘--lib’ command line argument.
gl_LGPL
The presence of this macro without arguments corresponds to the ‘--lgpl’ command line argument. The presence of this macro with an argument (whose value must be 2 or 3) corresponds to the ‘--lgpl=arg’ command line argument.
gl_LIBTOOL
The presence of this macro corresponds to the ‘--libtool’ command line argument and to the absence of the ‘--no-libtool’ command line argument. It takes no arguments.
gl_MACRO_PREFIX
The argument is the prefix to use for macros in the gnulib-comp.m4 file. Corresponds to the ‘--macro-prefix’ command line argument.
When you want to update to a more recent version of Gnulib, without changing the list of modules or other parameters, a simple call does it:
$ gnulib-tool --add-import
This will create, update or remove files, as needed.
Note: From time to time, changes are made in Gnulib that are not backward compatible. When updating to a more recent Gnulib, you should consult Gnulib’s NEWS file to check whether the incompatible changes affect your project.
Gnulib contains some header file overrides. This means that when building on systems with deficient header files in /usr/include/, it may create files named string.h, stdlib.h, stdint.h or similar in the build directory. In the other source directories of your package you will usually pass ‘-I’ options to the compiler, so that these Gnulib substitutes are visible and take precedence over the files in /usr/include/.
These Gnulib substitute header files rely on <config.h> being already included. Furthermore <config.h> must be the first include in every compilation unit. This means that to all your source files and likely also to all your tests source files you need to add an ‘#include <config.h>’ at the top. Which source files are affected? Exactly those whose compilation includes a ‘-I’ option that refers to the Gnulib library directory.
This is annoying, but inevitable: On many systems, <config.h> is
used to set system dependent flags (such as _GNU_SOURCE
on GNU systems),
and these flags have no effect after any system header file has been included.
When you use Gnulib, you need to augment the set of libraries against which
your programs and libraries are linked. This is done by augmenting the
Automake variable LDADD
(for all programs) or
prog_LDADD
(for a single program prog
) or
library_la_LIBADD
(for a single library library.la
).
What do you need to add to this Automake variable?
lib/libgnu.a
for source in the
top-level directory, or ../lib/libgnu.a
for source in a sibling
directory of lib/
.
gnulib-tool
. Alternatively,
you can retrieve the set of additional libraries required by a specific
Gnulib module by running
./gnulib-tool --extract-recursive-link-directive module
Beware: By looking into the module description file modules/module
or by running
./gnulib-tool --extract-link-directive module
you would miss the link dependencies of indirectly used modules.
Gnulib contains a wealth of portability workarounds for ISO C and POSIX functions. They are listed in detail in the chapter ISO C and POSIX Function Substitutes. If you want to know which function substitutes are recommended for your package, you can search your source code for ISO C and POSIX functions that it uses and read the corresponding sections of said documentation chapter. But this is a tedious task. Here is an alternative approach that makes this task easier.
make distclean
if you previously built in the top-level directory.
Then regenerate the Autotools-generated parts of the package.
make distclean
.
In some cases, you may want to set additional compiler options for
use within the Gnulib import directory. For example, the
‘relocatable’ module operates better if you define the C macros
ENABLE_COSTLY_RELOCATABLE
and INSTALLDIR
during its
compilation.
There are two ways to do so: Use of the gnulib-tool
option
--makefile-name
, and a kitchen-sink module.
With the gnulib-tool
option --makefile-name
, you are
telling gnulib-tool
to generate an includable Makefile.am
portion, rather than a self-contained Makefile.am
. For example,
when you use --makefile-name=Makefile.gnulib
, gnulib-tool
will generate Makefile.gnulib
, and you will provide a
hand-written Makefile.am
that includes Makefile.gnulib
through a line such as
include Makefile.gnulib
Before this include, you need to initialize this set of Makefile.am
variables:
AUTOMAKE_OPTIONS
SUBDIRS
noinst_HEADERS
noinst_LIBRARIES
noinst_LTLIBRARIES
pkgdata_DATA
(only with Automake ≥ 1.11.4)
EXTRA_DIST
BUILT_SOURCES
SUFFIXES
MOSTLYCLEANFILES
MOSTLYCLEANDIRS
CLEANFILES
DISTCLEANFILES
MAINTAINERCLEANFILES
AM_CPPFLAGS
AM_CFLAGS
AUTOMAKE_OPTIONS
should be initialized as described in
Changing Automake’s Behavior in GNU Automake.
The other variables can be initialized to empty. However, you will most
likely want to initialize some of them with non-empty values, in order
to achieve the desired customization.
The other approach, the kitchen-sink module, is more advanced. See chapter Extending Gnulib.
By default, the Gnulib import directory will contain a generated
Makefile.am
file. After configuring, this produces a generated
Makefile
in this directory. As a consequence, the build from the
top-level directory will use a recursive make
invocation for this
directory.
Some people prefer a build system where the Makefile
in the
top-level directory directly builds the artifacts in the subdirectories,
without an intermediate make
invocation. This is called
“non-recursive make” and is supported by Automake. For more details,
see https://autotools.io/automake/nonrecursive.html.
Gnulib supports this flavour of build system too. To use it, pass two
options to gnulib-tool
: ‘--makefile-name’ and
‘--automake-subdir’.
With the gnulib-tool
option ‘--makefile-name’, you are
telling gnulib-tool
to generate an includable Makefile.am
portion in the Gnulib import directory, rather than a self-contained
Makefile.am
. For example, when you use
‘--makefile-name=Makefile.gnulib’, gnulib-tool
will generate
Makefile.gnulib
.
With the option ‘--automake-subdir’, you are telling
gnulib-tool
that you will include the generated file from the
Makefile.am
in the top-level directory, rather than from a
Makefile.am
in the same directory. For example, the top-level
Makefile.am
might contain this directive:
include lib/Makefile.gnulib
The option ‘--automake-subdir’ is also supported in combination
with ‘--with-tests’ (see Bundling the unit tests of the Gnulib modules). Note that in this case,
however, the generated unit tests directory will contains a
Makefile.am
and thus use a recursive make
invocation.
This is not a problem, since the built artifacts of your package have
no dependencies towards the Gnulib unit tests, nor vice versa.
Your project might build both a library and some accompanying programs
in the same source tree. In that case you might want to use different
modules for the library than for the programs. Typically the programs
might want to make use of getopt-posix
or version-etc
,
while the library wants to stay clear of these modules for technical
or licensing reasons.
Let’s assume that your project contains a lib directory where the source of the library resides and a src directory for the sources of the programs as follows.
. |-- configure.ac |-- lib | |-- foo.c | `-- Makefile.am |-- Makefile.am `-- src |-- bar.c `-- Makefile.am
You can now add two instances of Gnulib to your project in separate source trees:
~/src/libfoo$ gnulib-tool --import --lib=libgnu --source-base=gnulib \ --m4-base=gnulib/m4 --macro-prefix=gl strndup ~/src/libfoo$ gnulib-tool --import --lib=libgnutools \ --source-base=src/gnulib --m4-base=src/gnulib/m4 \ --macro-prefix=gl_tools getopt-gnu
The first one will import the module strndup
in gnulib
and the second one will import getopt-gnu
in src/gnulib
and you will end up with the following source tree (many files omitted
in the interest of brevity):
. |-- configure.ac |-- gnulib | |-- m4 | |-- strndup.c |-- lib | |-- foo.c | `-- Makefile.am |-- Makefile.am `-- src |-- bar.c |-- gnulib | |-- getopt.c | |-- getopt.in.h | |-- m4 `-- Makefile.am
As discussed in Bundling the unit tests of the Gnulib modules, you may not use ‘--with-tests’
for this project since the configure.ac
is shared.
Integration with your code is basically the same as outlined in
Initial import with the one exception that you have to add both
the macro gl_EARLY
and the macro gl_tools_EARLY
to your
configure.ac (and of course also both macros gl_INIT
and
gl_tools_INIT
). Obviously the name of the second macro is
dependent on the value of the --macro-prefix option in your
gnulib-tool
invocation.
... AC_PROG_CC gl_EARLY gl_tools_EARLY ... # For gnulib. gl_INIT gl_tools_INIT ...
Also as outlined in Initial import you will have to add compiler and linker flags. For the library you might have to add something along the line of the following to your Makefile.am:
... AM_CPPFLAGS = -I$(top_srcdir)/gnulib -I$(top_builddir)/gnulib ... libfoo_la_LIBADD = $(top_builddir)/gnulib/libgnu.la ...
Correspondingly for the programs you will have to add something like this:
... AM_CPPFLAGS = -I$(top_srcdir)/src/gnulib -I$(top_builddir)/src/gnulib ... LDADD = $(top_builddir)/src/gnulib/libgnutools.la ...
The name of the library that you have pass in the linker option
depends on the --lib option in gnulib-tool
invocation.
gettextize
and autopoint
users ¶The programs gettextize
and autopoint
, part of
GNU gettext
, import or update the internationalization infrastructure.
Some of this infrastructure, namely ca. 20 Autoconf macro files and the
config.rpath file, is also contained in Gnulib and may be imported
by gnulib-tool
. The use of gettextize
or autopoint
will therefore overwrite some of the files that gnulib-tool
has
imported, and vice versa.
Avoiding to use gettextize
(manually, as package maintainer) or
autopoint
(as part of a script like autoreconf
or
autogen.sh
) is not the solution: These programs also import the
infrastructure in the po/ and optionally in the intl/ directory.
The copies of the conflicting files in Gnulib are more up-to-date than
the copies brought in by gettextize
and autopoint
. When a
new gettext
release is made, the copies of the files in Gnulib will
be updated immediately.
The choice of which version of gettext to require depends on the needs of your package. For a package that wants to comply to GNU Coding Standards, the steps are:
gettextize
, always use the gettextize
from the
matching GNU gettext release. For the most recent Gnulib checkout, this is
the newest release found on https://ftp.gnu.org/gnu/gettext/. For an
older Gnulib snapshot, it is the release that was the most recent release
at the time the Gnulib snapshot was taken.
gettextize
, invoke gnulib-tool
and import
the gettext
module. Also, copy the latest version of gnulib’s
build-aux/po/Makefile.in.in to your po/ directory (this
is done for you if you use gnulib’s autogen.sh script).
*** error: gettext infrastructure mismatch:
using a Makefile.in.in from gettext version ...
but the Autoconf macros are from gettext version ...
,
it means that a new GNU gettext release was made, and its Autoconf macros
were integrated into Gnulib and now mismatch the po/ infrastructure.
In this case, fetch and install the new GNU gettext release and run
gettextize
followed by gnulib-tool
.
On the other hand, if your package is not as concerned with compliance to the latest standards, but instead favors development on stable environments, the steps are:
gettext
that you intend to
support during development (at this time, gnulib recommends going no
older than version 0.17). Run autopoint
(not
gettextize
) to copy infrastructure into place (newer versions
of gettext will install the older infrastructure that you requested).
gnulib-tool
, and import the gettext-h
module.
Regardless of which approach you used to get the infrastructure in place, the following steps must then be used to preserve that infrastructure (gnulib’s autogen.sh script follows these rules):
autopoint
, invoke gnulib-tool
afterwards.
autoreconf
after gnulib-tool
, make sure to
not invoke autopoint
a second time, by setting the AUTOPOINT
environment variable, like this:
$ env AUTOPOINT=true autoreconf --install
Gnulib provides some functions that emit translatable messages using GNU
gettext
. The ‘gnulib’ domain at the
Translation Project collects
translations of these messages, which you should incorporate into your
own programs.
There are two basic ways to achieve this. The first, and older, method is to list all the source files you use from Gnulib in your own po/POTFILES.in file. This will cause all the relevant translatable strings to be included in your POT file. When you send this POT file to the Translation Project, translators will normally fill in the translations of the Gnulib strings from their “translation memory”, and send you back updated PO files.
However, this process is error-prone: you might forget to list some source files, or the translator might not be using a translation memory and provide a different translation than another translator, or the translation might not be kept in sync between Gnulib and your package. It is also slow and causes substantial extra work, because a human translator must be in the loop for each language and you will need to incorporate their work on request.
For these reasons, a new method was designed and is now recommended. If
you pass the --po-base=directory
and --po-domain=domain
options to gnulib-tool
, then gnulib-tool
will create a
separate directory with its own POTFILES.in, and fetch current
translations directly from the Translation Project (using
rsync
or wget
, whichever is available).
The POT file in this directory will be called
domain-gnulib.pot, depending on the domain you gave to the
--po-domain
option (typically the same as the package name).
This causes these translations to reside in a separate message domain,
so that they do not clash either with the translations for the main part
of your package nor with those of other packages on the system that use
possibly different versions of Gnulib.
When you use these options, the functions in Gnulib are built
in such a way that they will always use this domain regardless of the
default domain set by textdomain
.
In order to use this method, you must—in each program that might use Gnulib code—add an extra line to the part of the program that initializes locale-dependent behavior. Where you would normally write something like:
setlocale (LC_ALL, ""); bindtextdomain (PACKAGE, LOCALEDIR); textdomain (PACKAGE);
you should add an additional bindtextdomain
call to inform
gettext of where the MO files for the extra message domain may be found:
bindtextdomain (PACKAGE "-gnulib", LOCALEDIR);
(This example assumes that the domain that you specified
to gnulib-tool
is the same as the value of the PACKAGE
preprocessor macro.)
Since you do not change the textdomain
call, the default message
domain for your program remains the same and your own use of gettext
functions will not be affected.
If a project stores its source files in a version control system (VCS), such as CVS, Subversion, or Git, one needs to decide which files to commit.
In principle, all files created by gnulib-tool
, except
gnulib-cache.m4, can be treated like generated source files,
like for example a parser.c file generated from
parser.y. Alternatively, they can be considered source files
and updated manually.
Here are the three different approaches in common use. Each has its place, and you should use whichever best suits your particular project and development methods.
gnulib-tool
generated files should all be
committed. In this case, you should pass the option
‘--no-vc-files’ to gnulib-tool
, which avoids alteration of
VCS-related files such as .gitignore.
Gnulib also contains files generated by make
(and removed by
make clean
), using information determined by
configure
. For a Gnulib source file of the form
lib/foo.in.h, the corresponding lib/foo.h is such a
make
-generated file. These should not be checked
into the VCS, but instead added to .gitignore or equivalent.
gnulib-tool
. The command for restoring the omitted files
depends on it:
gnulib-cache.m4
, such as
autogen.sh, bootstrap, bootstrap.conf, or similar,
the restoration command is the entire gnulib-tool ... --import ...
invocation with all options and module names.
gnulib-tool
’s memory of the last used
options and module names, then the file gnulib-cache.m4 in the M4
macros directory must be added to the VCS, and the restoration command
is:
$ gnulib-tool --update
The ‘--update’ option operates much like the ‘--add-import’ option, but it does not offer the possibility to change the way Gnulib is used. Also it does not report in the ChangeLogs the files that it had to add because they were missing.
Most packages nowadays use the first among these two approaches. Over time, three ways of handling version control have evolved.
In the cases (A) and (B), a “git submodule” is used to reference the precise commit of the gnulib repository, so that each developer running ‘./bootstrap --pull’ or autopull.sh will get the same version of all gnulib-provided files.
The alternative is to always follow the newest Gnulib automatically. Note that this can cause breakages at unexpected moments, namely when a broken commit is pushed in Gnulib. It does not happen often, but it does happen.
The location of the submodule can be chosen to fit the package’s needs; here’s how to initially create the submodule in the directory gnulib:
$ git submodule add -- https://git.savannah.gnu.org/git/gnulib.git gnulib
Thereafter, the developer will run this command to update the submodule to the recorded checkout level:
$ git submodule update --init gnulib
Use this sequence to update to a newer version of gnulib:
$ git submodule update --remote gnulib $ git add gnulib $ ./bootstrap --bootstrap-sync
If multiple submodules are used, the following may be useful:
$ git config alias.syncsub "submodule foreach git pull origin master" $ git syncsub
build-aux/bootstrap
or autopull.sh
program (see Programs for developing in Git checkouts) is used to aid a developer in
using this setup. You copy this program (and if it’s
autopull.sh
, its companion files) into your package and place
the copy or copies under version control. The program can be
customized using bootstrap.conf which you also put under
version control.
autopull.sh
and autogen.sh
files by hand.
autopull.sh
is most easily written as a script that
invokes
./gitsub.sh pull || exit 1
where gitsub.sh
is described in Programs for developing in Git checkouts.
autogen.sh
typically contains an explicit gnulib-tool
invocation, followed by
aclocal -I m4 \ && autoconf \ && autoheader && touch config.h.in \ && automake --add-missing --copy \ && rm -rf autom4te.cache \ || exit $?
Makefile.in
generated by Automake. This
increases the size and complexity of the repository, but can help
occasional contributors by not requiring them to have a full Gnulib
checkout to do a build, and all developers by ensuring that all
developers are working with the same version of Gnulib in the
repository. It also supports multiple Gnulib instances within a
project. It remains important not to commit the
make
-generated files, as described above.
You can bundle the unit tests of the Gnulib modules together with your
package, through the ‘--with-tests’ option. Together with
‘--with-tests’, you also specify the directory for these tests
through the ‘--tests-base’ option. Of course, you need to add this
directory to the SUBDIRS
variable in the Makefile.am
of
the parent directory.
The advantage of having the unit tests bundled is that when your program has a problem on a particular platform, running the unit tests may help determine quickly if the problem is on Gnulib’s side or on your package’s side. Also, it helps verifying Gnulib’s portability, of course.
The unit tests will be compiled and run when the user runs ‘make check’. When the user runs only ‘make’, the unit tests will not be compiled.
In the SUBDIRS
variable, it is useful to put the Gnulib tests directory
after the directory containing the other tests, not before:
SUBDIRS = gnulib-lib src man tests gnulib-tests
This will ensure that on platforms where there are test failures in either directory, users will see and report the failures from the tests of your program.
Note: In packages which use more than one invocation of gnulib-tool
in the scope of the same configure.ac
, you cannot use
‘--with-tests’. You will have to use a separate configure.ac
in this case.
In some cases, a module is needed by another module only on specific
platforms. But when a module is present, its Autoconf checks are always
executed, and its Makefile.am
additions are always enabled. So
it can happen that some Autoconf checks are executed and some source files
are compiled, although no other module needs them on this particular
platform, just in case some other module would need them.
The option ‘--conditional-dependencies’ enables an optimization of
configure checks and Makefile.am
snippets that avoids this. With
this option, whether a module is considered “present” is no longer decided
when gnulib-tool
is invoked, but later, when configure
is run.
This applies to modules that were added as dependencies while
gnulib-tool
was run; modules that were passed on the command line
explicitly are always “present”.
For example, the timegm
module needs, on platforms
where the system’s timegm
function is missing or buggy, a replacement
that is based on a function mktime_internal
. The module
mktime-internal
that provides this function provides it on all
platforms. So, by default, the file mktime-internal.c will be
compiled on all platforms, even on glibc and BSD systems which have a
working timegm
function. When the option
‘--conditional-dependencies’ is given, on the other hand, and if
mktime-internal
was not explicitly required on the command line,
the file mktime-internal.c will only be compiled on the platforms
where the timegm
needs them.
Conditional dependencies are specified in the module description by putting
the condition on the same line as the dependent module, enclosed in brackets.
The condition is a boolean shell expression that can assume that the
configure.ac
snippet from the module description has already been
executed. In the example above, the dependency from timegm
to
mktime-internal
is written like this:
Depends-on: ... mktime-internal [test $HAVE_TIMEGM = 0 || test $REPLACE_TIMEGM = 1] ...
Note: The option ‘--conditional-dependencies’ cannot be used together
with the option ‘--with-tests’. It also cannot be used when a package
uses gnulib-tool
for several subdirectories, with different values
of ‘--source-base’, in the scope of a single configure.ac
file.
This chapter explains how to write modules of your own, either to extend Gnulib for your own package (see Extending Gnulib), or for inclusion in gnulib proper.
The guidelines in this chapter do not necessarily need to be followed for
using gnulib-tool
. They merely represent a set of good practices.
Following them will result in a good structure of your modules and in
consistency with gnulib.
AC_LIBOBJ
Every API (C functions or variables) provided should be declared in a header file (.h file) and implemented in one or more implementation files (.c files). The separation has the effect that users of your module need to read only the contents of the .h file and the module description in order to understand what the module is about and how to use it—not the entire implementation. Furthermore, users of your module don’t need to repeat the declarations of the functions in their code, and are likely to receive notification through compiler errors if you make incompatible changes to the API (like, adding a parameter or changing the return type of a function).
The .h file should declare the C functions and variables that the module provides.
The .h file should be stand-alone. That is, it does not require other .h files to be included before. Rather, it includes all necessary .h files by itself.
It is a tradition to use CPP tricks to avoid parsing the same header file more than once, which might cause warnings. The trick is to wrap the content of the header file (say, foo.h) in a block, as in:
#ifndef FOO_H # define FOO_H ... body of header file goes here ... #endif /* FOO_H */
Whether to use FOO_H
or _FOO_H
is a matter of taste and
style. The C99 and C11 standards reserve all identifiers that begin with an
underscore and either an uppercase letter or another underscore, for
any use. Thus, in theory, an application might not safely assume that
_FOO_H
has not already been defined by a library. On the other
hand, using FOO_H
will likely lead the higher risk of
collisions with other symbols (e.g., KEY_H
, XK_H
, BPF_H
,
which are CPP macro constants, or COFF_LONG_H
, which is a CPP
macro function). Your preference may depend on whether you consider
the header file under discussion as part of the application (which has
its own namespace for CPP symbols) or a supporting library (that
shouldn’t interfere with the application’s CPP symbol namespace).
Adapting C header files for use in C++ applications can use another CPP trick, as in:
# ifdef __cplusplus extern "C" { # endif ... body of header file goes here ... # ifdef __cplusplus } # endif
The idea here is that __cplusplus
is defined only by C++
implementations, which will wrap the header file in an ‘extern "C"’
block. Again, whether to use this trick is a matter of taste and
style. While the above can be seen as harmless, it could be argued
that the header file is written in C, and any C++ application using it
should explicitly use the ‘extern "C"’ block itself. Your
preference might depend on whether you consider the API exported by
your header file as something available for C programs only, or for C
and C++ programs alike.
Note that putting a #include
in an extern "C" { ... }
block yields a syntax error in C++ mode on some platforms (e.g., glibc
systems with g++ v3.3 to v4.2, AIX, IRIX). For this reason, it
is recommended to place the #include
before the extern
"C"
block.
The .c file or files implement the functions and variables declared in the .h file.
Every implementation file must start with ‘#include <config.h>’.
This is necessary for activating the preprocessor macros that are defined
on behalf of the Autoconf macros. Some of these preprocessor macros,
such as _GNU_SOURCE
, would have no effect if defined after a system
header file has already been included.
Then comes the ‘#include "..."’ specifying the header file that is being implemented. Putting this right after ‘#include <config.h>’ has the effect that it verifies that the header file is self-contained.
Then come the system and application headers. It is customary to put all the system headers before all application headers, so as to minimize the risk that a preprocessor macro defined in an application header confuses the system headers on some platforms.
In summary:
The specification of a function should answer at least the following questions:
Where to put the specification describing exported functions? Three practices are used in gnulib:
In any case, the specification should appear in just one place, unless you can ensure that the multiple copies will always remain identical.
The advantage of putting it in the header file is that the user only has to read the include file normally never needs to peek into the implementation file(s).
The advantage of putting it in the implementation file is that when reviewing or changing the implementation, you have both elements side by side.
The advantage of texinfo formatted documentation is that it is easily published in HTML or Info format.
Currently (as of 2020), 70% of gnulib uses the first practice, 25% of gnulib uses the second practice, and a small minority uses the texinfo practice.
For the module description, you can start from an existing module’s description, or from a blank one: module/TEMPLATE for a normal module, or module/TEMPLATE-TESTS for a unit test module. Some more fields are possible but rarely used. Use module/TEMPLATE-EXTENDED if you want to use one of them.
Module descriptions have the following fields. Absent fields are equivalent to fields with empty contents.
This field should contain a concise description of the module’s functionality. One sentence is enough. For example, if it defines a single function ‘frob’, the description can be ‘frob() function: frobnication.’ Gnulib’s documentation generator will automatically convert the first part to a hyperlink when it has this form.
This field is either empty/absent, or contains the word ‘obsolete’. In
the latter case, gnulib-tool
will, unless the option
--with-obsolete
is given, omit it when it used as a dependency. It is
good practice to also notify the user about an obsolete module. This is done
by putting into the ‘Notice’ section (see below) text like
‘This module is obsolete.’
This field contains text that gnulib-tool
will show to the user
when the module is used. This can be a status indicator like
‘This module is obsolete.’ or additional advice. Do not abuse this
field.
This field is either empty/absent, or contains the word ‘all’. It
describes to which Makefile.am
the module is applied. By default,
a normal module is applied to source_base/Makefile.am
(normally lib/Makefile.am
), whereas a module ending in -tests
is applied to tests_base/Makefile.am
(normally
tests/Makefile.am
). If this field is ‘all’, it is applied to
both Makefile.am
s. This is useful for modules which provide
Makefile.am macros rather than compiled source code.
This field contains a newline separated list of the files that are part of
the module. gnulib-tool
copies these files into the package that
uses the module.
This list is typically ordered by importance: First comes the header file, then the implementation files, then other files.
It is possible to have the same file mentioned in multiple modules. That is, if the maintainers of that module agree on the purpose and future of said file.
This field contains a newline separated list of the modules that are required
for the proper working of this module. gnulib-tool
includes each
required module automatically, unless it is specified with option
--avoid
or it is marked as obsolete and the option
--with-obsolete
is not given.
A test modules foo-tests
implicitly depends on the corresponding non-test
module foo
. foo
implicitly depends on foo-tests
if the
latter exists and if the option --with-tests
has been given.
Tests modules can depend on non-tests modules. Non-tests modules should not depend on tests modules. (Recall that tests modules are built in a separate directory.)
Each listed required module may be declared a conditional dependency. This
is indicated by placing the condition for the dependency on the same line,
enclosed in brackets, after the name of the required module. The condition
is a shell expression that is run after the module’s configure.ac
statements. For example:
strtoull [test $ac_cv_func_strtoumax = no]
Lines starting with #
are recognized as comments and are ignored.
This field contains configure.ac stuff (Autoconf macro invocations and
shell statements) that are logically placed early in the configure.ac
file: right after the AC_PROG_CC
invocation. This section is adequate
for statements that modify CPPFLAGS
, as these can affect the results of
other Autoconf macros.
This field contains configure.ac stuff (Autoconf macro invocations and shell statements).
It is forbidden to add items to the CPPFLAGS
variable here, other than
temporarily, as these could affect the results of other Autoconf macros.
We avoid adding items to the LIBS
variable, other than temporarily.
Instead, the module can export an Autoconf-substituted variable that contains
link options. The user of the module can then decide to which executables
to apply which link options. Recall that a package can build executables of
different kinds and purposes; having all executables link against all
libraries is inappropriate.
If the statements in this section grow larger than a couple of lines, we
recommend moving them to a .m4
file of their own.
This field contains Makefile.am
statements. Variables like
lib_SOURCES
are transformed to match the name of the library
being built in that directory. For example, lib_SOURCES
may become
libgnu_a_SOURCES
(for a plain library) or libgnu_la_SOURCES
(for a libtool library). Therefore, the normal way of having an
implementation file lib/foo.c
compiled unconditionally is to write
lib_SOURCES += foo.c
This field contains the preprocessor statements that users of the module need to add to their source code files. Typically it’s a single include statement. A shorthand is allowed: You don’t need to write the word “#include”, just the name of the include file in the way it will appear in an include statement. Example:
"foo.h"
This field contains the set of libraries that are needed when linking
libraries or executables that use this module. Often this will be
written as a reference to a Makefile variable. Please write them
one per line, so that gnulib-tool
can remove duplicates
when presenting a summary to the user.
Example:
$(POW_LIBM) $(LTLIBICONV) when linking with libtool, $(LIBICONV) otherwise
When this field is omitted, it defaults to the union of the Link
field of the dependencies.
This field specifies the license that governs the source code parts of this module. See Copyright for details. Be sure to place, in every source code file, a copyright notice and the appropriate license notice, taken from the etc/license-notices/ directory.
This field specifies the persons who have a definitive say about proposed
changes to this module. You don’t need to mention email addresses here:
they can be inferred from the ChangeLog
file.
Please put at least one person here. We don’t like unmaintained modules.
For a module foo
, an Autoconf macro file m4/foo.m4 is typically
created when the Autoconf macro invocations for the module are longer than
one or two lines.
The name of the main entry point into this Autoconf macro file is typically
gl_FOO
. For modules outside Gnulib that are not likely to be moved
into Gnulib, please use a prefix specific to your package: gt_
for
GNU gettext, cu_
for GNU coreutils, etc.
For modules that define a function foo
, the entry point is called
gl_FUNC_FOO
instead of gl_FOO
. For modules that provide a
header file with multiple functions, say foo.h
, the entry point is
called gl_FOO_H
or gl_HEADER_FOO_H
. This convention is useful
because sometimes a header and a function name coincide (for example,
fcntl
and fcntl.h
).
For modules that provide a replacement, it is useful to split the Autoconf
macro into two macro definitions: one that detects whether the replacement
is needed and requests the replacement by setting a HAVE_FOO
variable to 0 or a REPLACE_FOO
variable to 1 (this is the
entry point, say gl_FUNC_FOO
), and one that arranges for the macros
needed by the replacement code lib/foo.c
(typically called
gl_PREREQ_FOO
). The reason of this separation is
lib/foo.c
, all you have to review
is the Depends-on
section of the module description and the
gl_PREREQ_FOO
macro in the Autoconf macro file.
AC_LIBOBJ
¶Source files that provide a replacement should be only compiled on the
platforms that need this replacement. While it is actually possible
to compile a .c
file whose contents is entirely #ifdef
’ed
out on the platforms that don’t need the replacement, this practice is
discouraged because
.o
file that suggests that a replacement was needed.
The typical idiom for invoking AC_LIBOBJ
is thus the following,
in the module description:
if test $HAVE_FOO = 0 || test $REPLACE_FOO = 1; then AC_LIBOBJ([foo]) gl_PREREQ_FOO fi
Important: Do not place AC_LIBOBJ
invocations in the Autoconf
macros in the m4/
directory. The purpose of the Autoconf macros
is to determine what features or bugs the platform has, and to make
decisions about which replacements are needed. The purpose of the
configure.ac
and Makefile.am
sections of the module
descriptions is to arrange for the replacements to be compiled.
Source file names do not belong in the m4/
directory.
When an AC_LIBOBJ
invocation is unconditional, it is simpler
to just have the source file compiled through an Automake variable
augmentation: In the Makefile.am
section write
lib_SOURCES += foo.c
When a module description contains an AC_LIBOBJ([foo])
invocation, you must list the source file lib/foo.c
in the Files
section. This is needed even if the module
depends on another module that already lists lib/foo.c
in its
Files
section – because your module might be used among
the test modules (in the directory specified through ‘--tests-base’)
and the other module among the main modules (in the directory specified
through ‘--source-base’), and in this situation, the
AC_LIBOBJ([foo])
of your module can only be satisfied by having
foo.c
be present in the tests source directory as well.
A unit test that is a simple C program usually has a module description as simple as this:
Files: tests/test-foo.c tests/macros.h Depends-on: configure.ac: Makefile.am: TESTS += test-foo check_PROGRAMS += test-foo
The test program tests/test-foo.c often has the following structure:
ASSERT
macro.
The body of the test, then, contains many ASSERT
invocations. When
a test fails, the ASSERT
macro prints the line number of the failing
statement, thus giving you, the developer, an idea of which part of the test
failed, even when you don’t have access to the machine where the test failed
and the reporting user cannot run a debugger.
Sometimes it is convenient to write part of the test as a shell script. (For example, in areas related to process control or interprocess communication, or when different locales should be tried.) In these cases, the typical module description is like this:
Files: tests/test-foo.sh tests/test-foo.c tests/macros.h Depends-on: configure.ac: Makefile.am: TESTS += test-foo.sh TESTS_ENVIRONMENT += FOO_BAR='@FOO_BAR@' check_PROGRAMS += test-foo
Here, the TESTS_ENVIRONMENT
variable can be used to pass values
determined by configure
or by the Makefile
to the shell
script, as environment variables. The Autoconf values EXEEXT
and srcdir
are already provided as environment variables,
through an initial value of TESTS_ENVIRONMENT
that
gnulib-tool
puts in place.
Regardless of the specific form of the unit test, the following guidelines should be respected:
ASSERT
macro already does so.
fputs ("Skipping test: multithreading not enabled\n", stderr); return 77;
Such a message helps detecting bugs in the autoconf macros: A simple message ‘SKIP: test-foo’ does not sufficiently catch the attention of the user.
Incompatible changes to Gnulib modules should be mentioned in Gnulib’s NEWS file. Incompatible changes here mean that existing source code may not compile or work any more.
We don’t mean changes in the binary interface (ABI), since
Gnulib modules are intended to be suitable for widespread use. Most problems with Gnulib can and should be fixed in a generic way, so that all of Gnulib’s users can benefit from the change. But occasionally a problem arises that is difficult or undesirable to fix generically, or a project that uses Gnulib may need to work around an issue before the Gnulib maintainers commit a final fix. Maintainers may also want to add their own pools of modules to projects as Gnulib “staging areas.”
The obvious way to make local changes to Gnulib modules is to use
gnulib-tool
to check out pristine modules, then to modify
the results in-place. This works well enough for short-lived
experiments. It is harder to keep modified versions of Gnulib modules
for a long time, even though Git (or another distributed version
control systems) can help out a lot with this during the development
process.
Git, however, doesn’t address the distribution issue. When a package
“foobar” needs a modified version of, say, stdint.in.h, it
either has to put a comment into foobar/autogen.sh saying
“Attention! This doesn’t work with a pristine Gnulib, you need this
and that patch after checking out Gnulib,” or it has to use the
‘--avoid=stdint’ option and provide the modified stdint
module in a different directory.
The --local-dir option to gnulib-tool
solves this
problem. It allows the package to override or augment Gnulib. This
means:
gnulib-tool
option --makefile-name.)
In a release tarball, you can distribute the contents of this --local-dir directory that will be combinable with newer versions of Gnulib, barring incompatible changes to Gnulib.
If the --local-dir=directory option is specified, then
gnulib-tool
looks in directory whenever it
reads a file from the Gnulib directory. Suppose gnulib-tool
is looking for file. Then:
gnulib-tool
uses
it instead of the file included in Gnulib.
gnulib-tool
uses the file from Gnulib after applying the diff
using the patch
program.
gnulib-tool
uses the file included in Gnulib.
You can specify the --local-dir multiple times. In this case, the first specified directory has the highest precedence. That is, a file found in one directory will shadow any file and file.diff in the later directories and in the Gnulib directory. And a file file.diff found in one directory will be applied on top of the combination of file and file.diff files found in the later directories and in the Gnulib directory.
Please make wise use of this option. It also allows you to easily hold back modifications you make to Gnulib macros in cases it may be better to share them.
The gnulib API does not have a standard error code for the out of memory error condition. Instead of adding a non-standard error code, gnulib has chosen to adopt a different strategy. Out of memory handling happens in rare situations, but performing the out of memory error handling after almost all API function invocations pollute your source code and might make it harder to spot more serious problems. The strategy chosen improves code readability and robustness.
For most applications, aborting the application with an error message when the out of memory situation occurs is the best that can be wished for. This is how the library behaves by default (using the ‘xalloc-die’ module).
However, we realize that some applications may not want to abort
execution in any situation. Gnulib supports a hook to let the
application regain control and perform its own cleanups when an out of
memory situation has occurred. The application can define a function
(having a void
prototype, i.e., no return value and no
parameters) and set the library variable
xalloc_die
to that function. The variable should be
declared as follows.
extern void (*xalloc_die) (void);
Gnulib will invoke this function if an out of memory error occurs. Note that the function should not return. Of course, care must be taken to not allocate more memory, as that will likely also fail.
Modules can be marked obsolete. This means that the problems they fix
don’t occur any more on the platforms that are reasonable porting targets
now. gnulib-tool
warns when obsolete modules are mentioned on the
command line, and by default ignores dependencies from modules to obsolete
modules. When you pass the option --with-obsolete
to
gnulib-tool
, dependencies to obsolete modules will be included,
however, unless blocked through an --avoid
option. This option
is useful if your package should be portable even to very old platforms.
In order to mark a module obsolete, you need to add this to the module description:
Status: obsolete Notice: This module is obsolete.
Test modules can be marked with some special status attributes. When a
test module has such an attribute, gnulib-tool --import
will not
include it by default.
The supported status attributes are:
c++-test
Indicates that the test is testing C++ interoperability. Such a test is useful in a C++ or mixed C/C++ package, but is useless in a C package.
longrunning-test
Indicates that the test takes a long time to compile or execute (more than five minutes or so). Such a test is better avoided in a release that is made for the general public.
privileged-test
Indicates that the test will request special privileges, for example, ask for the superuser password. Such a test may hang when run non-interactively and is therefore better avoided in a release that is made for the general public.
unportable-test
Indicates that the test is known to fail on some systems, and that there is no workaround about it. Such a test is better avoided in a release that is made for the general public.
gnulib-tool --import --with-tests
will not include tests marked with
these attributes by default. When gnulib-tool
is invoked with one
of the options --with-c++-tests
, --with-longrunning-tests
,
--with-privileged-tests
, --with-unportable-tests
, it
will include tests despite the corresponding special status attribute.
When gnulib-tool
receives the option --with-all-tests
,
it will include all tests regardless of their status attributes.
gnulib-tool --create-testdir --with-tests
and
gnulib-tool --create-megatestdir --with-tests
by default include all
tests of modules specified on the command line, regardless of their status
attributes. Tests of modules occurring as dependencies are not included
by default if they have one of these status attributes. The options
--with-c++-tests
, --with-longrunning-tests
,
--with-privileged-tests
, --with-unportable-tests
are
recognized here as well. Additionally, gnulib-tool
also
understands the options --without-c++-tests
,
--without-longrunning-tests
, --without-privileged-tests
,
--without-unportable-tests
.
In order to mark a module with a status attribute, you need to add it to the module description, like this:
Status: longrunning-test
If only a part of a test deserves a particular status attribute, you
can split the module into a primary and a secondary test module,
say foo-tests
and foo-extra-tests
. Then add a dependency
from foo-tests
to foo-extra-tests
, and mark the
foo-extra-tests
with the particular status attribute.
The normal way to design modules is that each module has its own code, and the module dependencies provide the facilities on which this code can rely. But sometimes it is necessary to use more advanced techniques. For example:
n
against zero when you call malloc (n)
.
Be aware that these advanced techniques likely cause breakage in the
situation of multiple gnulib-tool
invocations in the scope of a
single configure
file. This is because the question “is module
B present?” does not have a unique answer in such situations.
gnulib-tool
has support for these techniques in the situation of
--create-testdir --single-configure
, which basically has two
gnulib-tool
invocations, one for a set of modules that end up in
gllib
, and one for the set of modules that end up in
gltests
. But you should be aware that this does not cover the
general situation.
Which technique to use, depends on the answer to the question: “If my
module occurs among the modules of gltests
, should it have an
effect on the modules in gllib
?”
If the answer is “no”, your module description should invoke the
Autoconf macro gl_MODULE_INDICATOR
. This Autoconf macro takes
one argument: the name of your module. The effect of
gl_MODULE_INDICATOR([my-module])
is to define, in
config.h
, a C macro GNULIB_MY_MODULE
that indicates
whether your macro is considered to be present. This works even when
your macro is used in gltests
: GNULIB_MY_MODULE
will then evaluate to 1 in gltests
but to 0 in gllib
.
If the answer is “yes”, you have two techniques available. The first
one is to invoke a similar Autoconf macro, named
gl_MODULE_INDICATOR_FOR_TESTS
. It works similarly. However,
when your macro is used in gltests
, GNULIB_MY_MODULE
will evaluate to 1 both in gltests
and in gllib
.
The second one is to define a shell variable in the configure
file that tells whether your module is present, through use of
m4_divert_text
. The Autoconf macros of a dependency module will
initialize this shell variable, through
‘m4_divert_text([DEFAULTS], [my_shell_var=no])’. The
Autoconf macros of your module will override this value, through
‘m4_divert_text([INIT_PREPARE], [my_shell_var=yes])’. Then
you can use my_shell_var
in the Autoconf macros of both
modules. You can find more details about this technique in the Gnulib
module getopt-gnu
.
Reminder: These techniques are advanced. They have the potential to cause lots of headaches if you apply them incorrectly.
The function definitions provided by Gnulib (.c
code) are meant
to be compiled by a C compiler. The header files (.h
files),
on the other hand, can be used in either C or C++.
By default, when used in a C++ compilation unit, the .h
files
declare the same symbols and overrides as in C mode, except that functions
defined by Gnulib or by the system are declared as ‘extern "C"’.
It is also possible to indicate to Gnulib to provide many of its symbols
in a dedicated C++ namespace. If you define the macro
GNULIB_NAMESPACE
to an identifier, many functions will be defined
in the namespace specified by the identifier instead of the global
namespace. For example, after you have defined
#define GNULIB_NAMESPACE gnulib
at the beginning of a compilation unit, Gnulib’s <fcntl.h>
header
file will make available the open
function as gnulib::open
.
The symbol open
will still refer to the system’s open
function,
with its platform specific bugs and limitations.
The symbols provided in the Gnulib namespace are those for which the
corresponding header file contains a _GL_CXXALIAS_RPL
or
_GL_CXXALIAS_SYS
macro invocation.
The benefits of this namespace mode are:
open
has to be overridden, Gnulib normally does
#define open rpl_open
. If your package has a class with a member
open
, for example a class foo
with a method foo::open
,
then if you define this member in a compilation unit that includes
<fcntl.h>
and use it in a compilation unit that does not include
<fcntl.h>
, or vice versa, you will get a link error. Worse: You
will not notice this problem on the platform where the system’s open
function works fine. This problem goes away in namespace mode.
gnulib::open
in your code, and you forgot to request the module
‘open’ from Gnulib, you will get a compilation error (regardless of
the platform).
The drawback of this namespace mode is that the system provided symbols in
the global namespace are still present, even when they contain bugs that
Gnulib fixes. For example, if you call open (...)
in your code,
it will invoke the possibly buggy system function, even if you have
requested the module ‘open’ from gnulib-tool.
You can turn on the namespace mode in some compilation units and keep it turned off in others. This can be useful if your package consists of an application layer that does not need to invoke POSIX functions and an operating system interface layer that contains all the OS function calls. In such a situation, you will want to turn on the namespace mode for the application layer—to avoid many preprocessor macro definitions—and turn it off for the OS interface layer—to avoid the drawback of the namespace mode, mentioned above.
Gnulib provides copies of the GNU GPL, GNU LGPL, GNU Affero GPL, and
GNU FDL licenses in Texinfo form. (The master location is
https://www.gnu.org/licenses/). These Texinfo documents do not
have any node names and structures built into them; for your manual,
you should @include
them in an appropriate @node
.
The conventional name for the GPL node is ‘Copying’ and for the FDL ‘GNU Free Documentation License’. The LGPL doesn’t seem to have a conventional node name.
Of course the license texts themselves should not be changed at all.
The recommended way to make use of these license files, consistently with current practice, is as follows:
To make use of the code license in your documentation, you may request
one of the modules gpl-3.0
, gpl-2.0
, lgpl-3.0
,
lgpl-2.1
, agpl-3.0
, through a gnulib-tool
invocation.
Or you may copy the relevant Texinfo file directly into your VCS repository.
Both approaches are equally good. The Texinfo file changes very rarely.
To make use of this documentation license, copy the relevant Texinfo
file (doc/fdl-1.3.texi
) into your VCS repository. This makes
sure that anyone who receives a copy of your VCS repository has also
received a copy of the documentation license. In the documentation,
also state what are the Invariant Sections, the Front-Cover Texts, and
the Back-Cover Texts.
We recommend to place the licenses as appendices at the end of the
manual, right before any indices. For the FDL, we suggest the following
@menu
entry:
* GNU Free Documentation License:: License for copying this manual
For any @detailmenu
entries, we suggest the following:
Copying This Manual * GNU Free Documentation License:: Copying and sharing this manual
And for actual inclusion of the FDL itself, we suggest the following:
@node GNU Free Documentation License @appendix GNU Free Documentation License @include fdl.texi
If you wish to help the gnulib development effort with build logs for your favorite platform, you may perform these steps:
Install the proper development tools. To build and test all of
Gnulib, you will need development tools for the programming languages
C, C++, Java, and Perl, along with standard POSIX utilities such as
awk
, make
and sh
. You will also need
development tools that include Autoconf, Automake, Bison, Gettext,
Git, GNU M4, Gperf, Libtool, and Texinfo. Some of these tools are
needed only by some modules. More details can be found in Gnulib’s
DEPENDENCIES file.
See https://www.gnu.org/software/gnulib/ for how to get the current Gnulib sources via Git.
On a machine with GNU development tools installed and with a gnulib git checkout, use
gnulib-tool --create-megatestdir --with-tests --dir=...
Note: The created directory uses ca. 512 MB on disk.
Transfer this directory to a build machine (HP-UX, Cygwin, or whatever). Often it is easier to transfer one file, and this can be achieved by running, inside the directory the following commands:
./configure make dist
And then transferring the dummy-0.tar.gz file.
On the build machine, run ./do-autobuild (or "nohup ./do-autobuild"). It creates a directory logs/ with a log file for each module.
This section shows a radically different way to use Gnulib.
You can extract the ISO C / POSIX substitutes part of gnulib by running the command
gnulib-tool --create-testdir --source-base=lib \ --dir=/tmp/posixlib `posix-modules`
The command ‘posix-modules’ is found in the same directory as
gnulib-tool
.
The resulting directory can be built on a particular platform,
independently of the program being ported. Then you can configure and
build any program, by setting CPPFLAGS
and LDFLAGS
at
configure time accordingly: set CPPFLAGS="-I.../posixlib/lib"
, plus
any essential type definitions and flags that you find in
.../posixlib/config.h
, and set
LDFLAGS=".../posixlib/lib/libgnu.a"
.
This way of using Gnulib is useful when you don’t want to modify the program’s
source code, or when the program uses a mix between C and C++ sources
(requiring separate builds of the posixlib
for the C compiler and
for the C++ compiler).
This chapter describes which keywords specified by ISO C are substituted by Gnulib.
alignof
and alignas
¶Gnulib module: alignasof
The alignasof
module arranges for alignas
and alignof
to be more like standard C.
Portability problems fixed by Gnulib:
alignas
and alignof
.
<stdalign.h>
must be included before
using alignas
or alignof
.
See stdalign.h.
Portability problems not fixed by Gnulib:
alignas
and alignof
are macros.
bool
¶Gnulib module: stdbool
Portability problems fixed by Gnulib:
bool
, true
, and false
are not available:
gcc 12 and other compilers predating C23.
Portability problems not fixed by Gnulib:
nullptr
¶Gnulib module: nullptr
The nullptr
module arranges for nullptr
to act
like standard C and C++.
The nullptr
keyword yields a null pointer. It differs from
the NULL
macro, in that NULL
might be an integer whereas
nullptr
is of a special nullptr_t
type with only one
value, namely nullptr
itself. Using nullptr
can help
some compilers emit more sensible warnings, can avoid the need to cast
a null pointer passed to a function prototyped with an ellipsis, and
removes the need to include <stddef.h>
merely to define
NULL
.
Portability problems fixed by Gnulib:
nullptr
:
For C: GCC 12, Clang 15, and other pre-2023 C compilers.
For C++: pre-2011 C++ compilers.
Portability problems not fixed by Gnulib:
nullptr
is a macro instead of a keyword.
nullptr
does not have the type nullptr_t
.
In C, it has type void *
; in C++ it has an integer type.
nullptr_t
, so
null pointer type checking is more error prone. In C, _Generic
expressions cannot reliably distinguish the type of nullptr
from integer or void *
types. C++ overloading has similar
limitations.
static_assert
¶Gnulib module: assert-h
The assert-h
module arranges for both static_assert
and
<assert.h>
to be like standard C. See assert.h.
Portability problems fixed by Gnulib:
static_assert
.
<assert.h>
must be included before
using static_assert
.
Portability problems not fixed by Gnulib:
static_assert
is a macro.
This chapter describes which header files specified by ISO C or POSIX are substituted by Gnulib, which portability pitfalls are fixed by Gnulib, and which (known) portability problems are not worked around by Gnulib.
The notation “Gnulib module: —” means that Gnulib does not provide a
module providing a substitute for the header file. When the list
“Portability problems not fixed by Gnulib” is empty, such a module is
not needed: No portability problems are known. Otherwise, it indicates
that such a module would be useful but is not available: No one so far
found this header file important enough to contribute a substitute for it.
If you need this particular header file, you may write to
<bug-gnulib at gnu dot org>
.
POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/aio.h.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/arpa_inet.h.html
Gnulib module: arpa_inet
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/assert.h.html
Gnulib module: assert-h
See also the Gnulib modules assert
and verify
.
Portability problems fixed by Gnulib:
<assert.h>
must be included before using
static_assert
. For example, GCC versions before 13 do not
support the static_assert
keyword that was standardized by C23.
static_assert
does not allow the second
string-literal argument to be omitted. For example, GCC versions
before 9.1 do not support the single-argument static_assert
that was standardized by C23 and C++17.
static_assert
at all.
For example, GCC versions before 4.6 and G++ versions before 4.3
do not support the two-argument form, which was standardized
by C11 and C++11.
_Static_assert
keyword or macro.
This portability problem should not matter with code using this
module, as such code should use static_assert
instead.
Portability problems not fixed by Gnulib:
static_assert
can also
be used within a struct
or union
specifier, in place of
an ordinary declaration of a member of the struct or union. The
Gnulib substitute can be used only as an ordinary declaration
in code intended to be portable to C99 or earlier.
static_assert
is a keyword.
In C11 and C17 it is a macro. Any Gnulib substitute is also a macro.
assert
can be applied to any scalar expression.
In C89, the argument to assert
is of type int
.
POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/complex.h.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/cpio.h.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/ctype.h.html
Gnulib module: ctype
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/dirent.h.html
Gnulib module: dirent
Portability problems fixed by Gnulib:
ino_t
is missing on some platforms:
glibc 2.23 and others.
Portability problems not fixed by Gnulib:
struct dirent
member named
d_type
and directory entry type macros like DT_DIR
and
DT_LNK
, some do not:
Minix 3.1.8, AIX 7.2, HP-UX 11, IRIX 6.5, Solaris 11.4, mingw.
d_type
, not every filesystem supports
d_type
, and those lacking support will set it to DT_UNKNOWN
.
struct dirent
member named d_namlen
containing the string length of d_name
, but others do not:
glibc 2.23 on Linux, Minix 3.1.8, Solaris 11.4, Cygwin.
All of these, except Cygwin, have a member d_reclen
instead,
that has a different semantics.
struct dirent
member named d_off
containing a magic cookie suitable as an argument to seekdir
,
but others do not:
glibc 2.23 on Hurd, macOS 11.1, FreeBSD 11.0, NetBSD 9.0, OpenBSD 6.7, AIX 5.1, HP-UX 11, Cygwin, mingw.
struct dirent
member named
d_reclen
containing the number of bytes in the directory entry
record, but others do not. This member has limited utility, as it is
an implementation detail.
POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/dlfcn.h.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/errno.h.html
Gnulib module: errno
Portability problems fixed by Gnulib:
EOVERFLOW
is not defined
on some platforms:
OpenBSD 4.0, mingw, MSVC 9.
ENOLINK
is not defined
on some platforms:
OpenBSD 6.7, mingw, MSVC 9.
EMULTIHOP
is not defined
on some platforms:
OpenBSD 6.7, mingw, MSVC 14.
ECANCELED
is not defined on some platforms:
OpenBSD 4.0, Cygwin, mingw, MSVC 9.
ENOMSG
, EIDRM
, EPROTO
, EBADMSG
,
ENOTSUP
are not defined on some platforms:
OpenBSD 4.0, mingw, MSVC 9.
ESTALE
is not defined on some platforms:
mingw, MSVC 14.
EDQUOT
is not defined on some platforms:
NonStop Kernel, mingw, MSVC 14.
ENETRESET
, ECONNABORTED
are not defined on some
platforms:
Minix 3.1.8, mingw, MSVC 9.
EWOULDBLOCK
, ETXTBSY
, ELOOP
, ENOTSOCK
,
EDESTADDRREQ
, EMSGSIZE
, EPROTOTYPE
, ENOPROTOOPT
,
EPROTONOSUPPORT
, EOPNOTSUPP
, EAFNOSUPPORT
,
EADDRINUSE
, EADDRNOTAVAIL
, ENETDOWN
, ENETUNREACH
,
ECONNRESET
, ENOBUFS
, EISCONN
, ENOTCONN
,
ETIMEDOUT
, ECONNREFUSED
, EHOSTUNREACH
, EALREADY
,
EINPROGRESS
are not defined on some platforms:
mingw, MSVC 9.
EOWNERDEAD
, ENOTRECOVERABLE
are not defined on
some platforms:
glibc/Linux 2.3.6, glibc/Hurd 2.15, glibc/kFreeBSD 2.15,
Mac OS X 10.5, FreeBSD 6.0, NetBSD 9.0, OpenBSD 6.0, Minix 3.1.8, AIX 5.1, HP-UX 11, IRIX 6.5, Cygwin, mingw without pthreads-win32, MSVC 9.
EILSEQ
is not defined on some platforms:
LynxOS 178 2.2.2.
Portability problems not fixed by Gnulib:
POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/fcntl.h.html
Gnulib module: fcntl-h
Portability problems fixed by Gnulib:
pid_t
is not defined on some platforms:
MSVC 14.
mode_t
is not defined on some platforms:
MSVC 14.
int
on some platforms:
AIX 7.1 with XL C 12.1.
int
on some
platforms:
Solaris 11.3.
Portability problems not fixed by Gnulib:
POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/fenv.h.html
Gnulib module: fenv
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
FE_UPWARD
is 0x100 and FE_DOWNWARD
is 0x200,
whereas in MSVC 14.30, it’s the opposite.
POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/float.h.html
Gnulib module: float
Portability problems fixed by Gnulib:
int
to long double
in incorrect on some
platforms:
glibc 2.7 on Linux/SPARC64.
LDBL_*
macros are incorrect on some platforms:
On OpenBSD 4.0 and MirBSD 10, they are the same as the values of the
DBL_*
macros, although ‘long double’ is a larger type than
‘double’.
On FreeBSD/x86 6.4, they represent the incorrect 53-bit precision assumptions
in the compiler, not the real 64-bit precision at runtime.
On Linux/PowerPC with GCC 4.4, on AIX 7.1 with GCC 4.2, and on IRIX 6.5,
they don’t reflect the “double double” representation of long double
correctly.
Portability problems not fixed by Gnulib:
FLT_ROUNDS
is a constant expression and does not represent
the current rounding mode on some platforms:
glibc 2.11, HP-UX 11, mingw.
POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/fmtmsg.h.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/fnmatch.h.html
Gnulib module: fnmatch-h, fnmatch-gnu
Portability problems fixed by Gnulib module fnmatch-h
:
Portability problems fixed by Gnulib module fnmatch-gnu
, together with module fnmatch-h
:
FNM_LEADING_DIR
and FNM_CASEFOLD
are not defined
on some platforms:
AIX 7.2, HP-UX 11.31, IRIX 6.5, Solaris 10.
FNM_EXTMATCH
is not defined on all non-glibc platforms:
musl libc, macOS 12.5, FreeBSD 13.2, NetBSD 9.3, OpenBSD 7.2, Minix 3.3, AIX 7.2, HP-UX 11.31, IRIX 6.5, Solaris 11.4, Cygwin 3.4.6, Android 13.
FNM_FILE_NAME
is not defined on some platforms:
NetBSD 9.3, AIX 7.2, HP-UX 11.31, IRIX 6.5, Solaris 10.
Portability problems not fixed by Gnulib:
POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/ftw.h.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/glob.h.html
Gnulib module: glob-h
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/grp.h.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/iconv.h.html
Gnulib module: iconv
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/inttypes.h.html
Gnulib module: inttypes
Portability problems fixed by Gnulib:
imaxabs
and imaxdiv
are missing on some
platforms:
NetBSD 3.0, OpenBSD 6.7, AIX 5.1, HP-UX 11, IRIX 6.5.
strtoimax
and strtoumax
are missing on some
platforms:
OpenBSD 6.7, AIX 5.1 (missing only strtoumax
).
__STDC_FORMAT_MACROS
to make visible the declarations of format
macros such as PRIdMAX
.
Portability problems not fixed by Gnulib:
POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/iso646.h.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/langinfo.h.html
Gnulib module: langinfo
Portability problems fixed by Gnulib:
CODESET
is not defined on some platforms:
OpenBSD 6.7.
ALTMON_1
to ALTMON_12
are not defined on some
platforms:
glibc 2.26, musl libc, macOS 11.1, NetBSD 8.0, OpenBSD 6.5, AIX 7.2, HP-UX 11.31, IRIX 6.5, Solaris 11.4, Haiku, Cygwin 2.9.
ERA
, ERA_D_FMT
, ERA_D_T_FMT
,
ERA_T_FMT
, ALT_DIGITS
are not defined on some platforms:
OpenBSD 6.7.
Portability problems not fixed by Gnulib:
POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/libgen.h.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
The Gnulib module dirname
provides similar API, with functions
base_name
and dir_name
that also work with Windows file names.
POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/limits.h.html
Gnulib module: limits-h or gethostname
Portability problems fixed by Gnulib module limits-h
:
LLONG_MIN
, LLONG_MAX
, ULLONG_MAX
are not
defined on some platforms:
older glibc systems (e.g. Fedora 1), AIX 5.1, HP-UX 11, IRIX 6.5, OpenVMS.
MB_LEN_MAX
is not defined on some platforms:
pcc 1.2.0.DEVEL 20220331.
WORD_BIT
, LONG_BIT
are not defined on some platforms:
glibc 2.11 without -D_GNU_SOURCE
, Cygwin, mingw, MSVC 14.
CHAR_WIDTH
are not defined on some platforms:
glibc 2.24, NetBSD 9.0, many others.
BOOL_MAX
and BOOL_WIDTH
are not defined on
some platforms:
glibc 2.32, many others.
BOOL_MAX
is not defined with some compilers:
clang 15.0.6.
SSIZE_MAX
is not defined on some platforms:
MSVC 14.
Portability problems fixed by Gnulib module gethostname
:
HOST_NAME_MAX
macro is not defined on some platforms:
macOS 11.1, FreeBSD 13.0, NetBSD 9.0, OpenBSD 6.7, AIX 5.1, HP-UX 11,
IRIX 6.5, Solaris 11.4, Cygwin 1.5.x, mingw, MSVC 14.
Portability problems not fixed by Gnulib:
SSIZE_MAX
has the wrong type,
albeit with the correct value:
32-bit glibc 2.24 (on some architectures), Cygwin 2.5.2.
For PATH_MAX
, Gnulib provides a module pathmax
with a header
file "pathmax.h"
. It defines PATH_MAX
to a constant on
platforms with a file name length limit.
POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/locale.h.html
Gnulib module: locale
Portability problems fixed by Gnulib:
locale_t
type is not defined on some platforms:
glibc 2.11, macOS 11.1.
struct lconv
type does not contain any members on some platforms:
Android up to 2014.
struct lconv
type does not contain the members
int_p_cs_precedes
, int_p_sign_posn
, int_p_sep_by_space
,
int_n_cs_precedes
, int_n_sign_posn
, int_n_sep_by_space
on some platforms:
glibc, OpenBSD 4.9, HP-UX 11, IRIX 6.5, Solaris 11.4, Cygwin 1.5.x, mingw, MSVC 14.
NULL
macro that cannot be used in arbitrary
expressions:
NetBSD 5.0
Portability problems not fixed by Gnulib:
POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/math.h.html
Gnulib module: math
Portability problems fixed by Gnulib:
int
to long double
in incorrect on some
platforms:
glibc 2.7 on Linux/SPARC64.
NAN
is not defined on some platforms:
OpenBSD 4.0, AIX 5.1, IRIX 6.5.
NAN
is not exposed outside of C99 compilation on some
platforms:
glibc.
NAN
and HUGE_VAL
expand to a function address
rather than a floating point constant on some platforms:
Solaris 10.
HUGE_VALF
and HUGE_VALL
are not defined on some
platforms:
glibc/HPPA, glibc/SPARC, AIX 5.1, IRIX 6.5, Solaris 9, MSVC 9.
FP_ILOGB0
and FP_ILOGBNAN
are not defined on some
platforms:
NetBSD 5.1, AIX 5.1, IRIX 6.5, Solaris 9, MSVC 9.
FP_ILOGB0
and FP_ILOGBNAN
have wrong values on some
platforms:
Haiku 2022.
NAN
, HUGE_VALL
, and INFINITY
are not
defined on some platforms:
OpenVMS.
Portability problems not fixed by Gnulib:
NAN
is not a compile time constant with some compilers:
OpenVMS.
math_errhandling
is not defined on some platforms:
glibc 2.11, OpenBSD 4.9, NetBSD 5.1, UP-UX 11, IRIX 6.5, Cygwin 1.7.9, mingw, MSVC 9.
POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/monetary.h.html
Gnulib module: monetary
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/mqueue.h.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/ndbm.h.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/net_if.h.html
Gnulib module: net_if
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/netdb.h.html
Gnulib module: netdb
Portability problems fixed by Gnulib:
socklen_t
on some platforms:
IRIX 6.5.
AI_ALL
, AI_V4MAPPED
on some platforms:
NetBSD 9.0.
AI_ADDRCONFIG
on some platforms:
NetBSD 5.0.
Portability problems not fixed by Gnulib:
POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/netinet_in.h.html
Gnulib module: netinet_in
Portability problems fixed by Gnulib:
<sys/types.h>
to be included first):
OpenBSD 4.6.
Portability problems not fixed by Gnulib:
POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/netinet_tcp.h.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/nl_types.h.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/poll.h.html
Gnulib module: poll-h
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/pthread.h.html
Gnulib module: pthread-h
Portability problems fixed by Gnulib:
strtok_r
and
gmtime_r
:
mingw 3.0.
Portability problems not fixed by Gnulib:
pthread_atfork
on some
platforms:
IRIX 6.5.
POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/pwd.h.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/regex.h.html
Gnulib module: regex
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<sys/types.h>
to be included first.
POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/sched.h.html
Gnulib module: sched
Portability problems fixed by Gnulib:
pid_t
on some platforms:
glibc 2.11, macOS 11.1.
struct sched_param
is not defined on some platforms:
Haiku.
SCHED_FIFO
, SCHED_RR
, SCHED_OTHER
are not defined on
some platforms:
Haiku.
Portability problems not fixed by Gnulib:
POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/search.h.html
Gnulib module: search
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/semaphore.h.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/setjmp.h.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/signal.h.html
Gnulib module: signal-h
Portability problems fixed by Gnulib:
volatile sig_atomic_t
is rejected by older compilers on some
platforms:
AIX.
sigset_t
is missing on some platforms:
MSVC 14.
sigset_t
is only declared in <sys/types.h> on some platforms:
mingw.
struct sigaction
and siginfo_t
are missing on some
platforms:
mingw, MSVC 14.
pid_t
is not defined on some platforms:
MSVC 14.
SIGPIPE
is not defined on some platforms:
mingw, MSVC 14.
SA_RESETHAND
and SA_RESTART
are not defined
on some platforms:
NonStop.
sighandler_t
(a GNU extension) is not defined on most non-glibc
platforms:
macOS 11.1, FreeBSD 13.0, NetBSD 9.0, OpenBSD 6.7, AIX 5.1, HP-UX 11,
IRIX 6.5, Solaris 11.4, Cygwin, mingw, MSVC 14.
Portability problems not fixed by Gnulib:
SIGBUS
is set to the same value as SIGSEGV
,
rather than being a distinct signal, on some platforms:
Haiku.
POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/spawn.h.html
Gnulib module: spawn
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
POSIX specification:
Not in POSIX yet, but we expect it will be,
at least temporarily until it becomes obsolete due to its phasing
out starting in C23.
ISO C23 (latest free draft
http://www.open-std.org/jtc1/sc22/wg14/www/docs/n3047.pdf)
sections 6.5.3.4, 6.7.5, 7.15.
C++11 (latest free draft
http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2011/n3242.pdf)
section 18.10.
Gnulib module: alignasof
Portability problems fixed by Gnulib:
<stdalign.h>
must be included before using
alignas
or alignof
. For example, GCC versions before 13 do not
support these keywords, which were standardized by C23.
On C23 and later platforms, <stdalign.h>
has no effect and need
not be included. (Gnulib-using code should not include
<stdalign.h>
without also employing Gnulib’s now-deprecated
stdalign
module.)
<stdalign.h>
does not define alignof
.
alignof
macro returns too large values for
the types double
and long long
in GCC 4.7.0.
_Alignas
and _Alignof
keywords or macros.
This portability problem should not matter with code using this module,
as such code should use alignas
and alignof
instead.
<stdalign.h>
defines the macros
__alignas_is_defined
and
__alignof_is_defined
to 1.
In C23, these macros are not defined.
This portability problem should not matter with code using Gnulib’s
alignasof
module, as such code should use alignas
and
alignof
without checking these two macros. (Gnulib’s
now-deprecated stdalign
module defines these two macros.)
Portability problems not fixed by Gnulib:
alignof
must be a
parenthesized type. Recent versions of GCC support an extension in
which the operand can also be a unary expression, as with
sizeof
. The Gnulib substitute does not support this extension.
alignof
cannot be a structure type containing a
flexible array member.
alignas
keyword or macro is not always supported.
Supported compilers include any compiler supporting C11 or later,
which includes GCC, IBM C, Sun C 5.9 and later,
and MSVC 7.0 and later.
alignas
of auto
variables (i.e.,
variables on the stack). They diagnose and ignore the alignment: Sun
C 5.11.
alignas
that are greater than 8: mingw.
alignas
to be a single integer constant, not an expression: MSVC 7.0 through
at least 10.0.
alignas
. The bug is fixed in Sun C 5.15, also known as Oracle
Developer Studio 12.6 (2017).
alignas
and alignof
are reserved words;
they might be macros.
POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/stdarg.h.html
Gnulib module: stdarg
Portability problems fixed by Gnulib:
va_copy
to work.
Portability problems not fixed by Gnulib:
POSIX specification:
Not in POSIX yet, but we expect it will be.
ISO C11 (latest free draft
http://www.open-std.org/jtc1/sc22/wg14/www/docs/n1570.pdf)
section 7.17.
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/stdbool.h.html
Gnulib module: stdbool-c99
The stdbool-c99
module is present only for programs that
formerly used the old stdbool
module for C99 compatibility,
and that for some reason cannot use the current stdbool
module
for C23 compatibility.
Portability problems fixed by Gnulib:
true
incorrectly on some platforms:
OpenBSD 4.7 with gcc 2.95.
Portability problems not fixed by Gnulib:
<stdbool.h>
is included, or if
the program is intended to be compiled by a C++ compiler.
(With the advent of C23, ‘_Bool’ is obsolescent anyway.)
_Bool
is a typedef; it might be a macro.
For example, C23 allows _Bool
to be a macro.
POSIX specification:
Not in POSIX yet, but we expect it will be.
ISO draft C23
(https://www.open-std.org/jtc1/sc22/wg14/www/docs/n3047.pdf)
section 7.20.
Gnulib module: stdckdint
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
stdckdint.h
macros can have side effects.
POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/stddef.h.html
Gnulib module: stddef
Portability problems fixed by Gnulib:
unreachable
, which was added in C23:
GCC 13, clang 15, AIX with xlc 12.1, Solaris with Sun C 5.15, and others.
max_align_t
, which was added in C11:
NetBSD 8.0, Solaris 11.0, and others.
max_align_t
does not have the expected alignment on some platforms:
NetBSD 8.0/x86, AIX 7.2 with xlc in 64-bit mode.
wchar_t
.
NULL
macro that cannot be used in arbitrary
expressions:
NetBSD 5.0
NULL
macro whose value does not have the size
of a pointer:
AIX 7.2 with xlc in 64-bit mode.
Portability problems not fixed by Gnulib:
nullptr_t
,
which Gnulib cannot usefully emulate:
GCC 12, Clang 15, and other pre-2023 C compilers.
offsetof
macro that cannot be used in
arbitrary expressions:
Solaris 11.4
This problem can be worked around by parenthesizing the
offsetof
expression in the unlikely case you use it with
sizeof
or ‘[]’.
POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/stdint.h.html
Gnulib module: stdint
Portability problems fixed by Gnulib:
SIG_ATOMIC_MIN
and SIG_ATOMIC_MAX
are incorrect
on some platforms:
FreeBSD 6.2/ia64, FreeBSD 13.0/arm64.
WINT_MAX
is incorrect on some platforms:
mingw.
INT8_MAX
, UINT8_MAX
etc. are not usable in
preprocessor expressions on some platforms:
HP-UX 11.23.
INTPTR_MAX
and UINTPTR_MAX
, although correctly
defined in <stdint.h>
, are replaced by empty values when
<limits.h>
or <inttypes.h>
gets included later on some platforms:
Solaris 9 with GCC 4.5 or newer.
WCHAR_MIN
and WCHAR_MAX
are not defined in
<stdint.h>
(only in <wchar.h>
) on some platforms:
Dragonfly.
__STDC_CONSTANT_MACROS
to make visible the definitions of
constant macros such as INTMAX_C
, and one must define
__STDC_LIMIT_MACROS
to make visible the definitions of limit
macros such as INTMAX_MAX
.
SIZE_MAX
has the wrong type,
albeit with the correct value:
32-bit glibc 2.24 (on s390 architecture), Mac OS X 10.7.
INTMAX_WIDTH
are not defined on some platforms:
glibc 2.24, NetBSD 9.0, many others.
Portability problems not fixed by Gnulib:
{uint,int}_fast{8,16,32,64}_t
may not correspond to the fastest
types available on the system.
Other <stdint.h>
substitutes may define these types differently,
so public header files should avoid these types.
long int
.
For example, as of 2007, Sun C mishandled #if LLONG_MIN < 0
on
a platform with 32-bit long int
and 64-bit long long int
;
this bug was fixed on or before Oracle Developer Studio 12.6
(Sun C 5.15 SunOS_sparc 2017/05/30).
Some older preprocessors mishandle constants ending in LL
.
To work around these problems, compute the value of expressions like
LONG_MAX < LLONG_MAX
at configure
-time rather than at
#if
-time.
The stdint
module uses #include_next
. If you wish to install
the generated stdint.h file under another name, typically in order to
be able to use some of the types defined by stdint.h in your public
header file, you could use the following Makefile.am-snippet:
BUILT_SOURCES += idn-int.h DISTCLEANFILES += idn-int.h nodist_include_HEADERS += idn-int.h idn-int.h: if test -n "$(STDINT_H)"; then \ sed -e s/include_next/include/ gl/stdint.h > idn-int.h; \ else \ echo '#include <stdint.h>' > idn-int.h; \ fi
POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/stdio.h.html
Gnulib module: stdio
Portability problems fixed by Gnulib:
off_t
is missing on some platforms:
glibc 2.8, eglibc 2.11.2 and others.
ssize_t
is missing on some platforms:
glibc 2.8, Mac OS X 10.5, Solaris 10, MSVC 14, and others.
va_list
is missing on some platforms:
glibc 2.8, OpenBSD 4.0, Solaris 11.4, and others.
NULL
macro that cannot be used in arbitrary
expressions:
NetBSD 5.0
Portability problems not fixed by Gnulib:
POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/stdlib.h.html
Gnulib module: stdlib, system-posix
Portability problems fixed by the Gnulib module stdlib
:
EXIT_SUCCESS
and EXIT_FAILURE
are not defined on
some platforms.
NULL
macro that cannot be used in arbitrary
expressions:
NetBSD 5.0
MB_CUR_MAX
is too small (3 instead of 4) in UTF-8 locales
on some platforms:
Solaris 10.
Portability problems fixed by the Gnulib module system-posix
:
WIFSIGNALED
, WIFEXITED
, WIFSTOPPED
,
WTERMSIG
, WEXITSTATUS
, WNOHANG
, WUNTRACED
,
WSTOPSIG
are not defined in this header file (only in
<sys/wait.h>
) on some platforms:
MirBSD 10.
Portability problems not fixed by Gnulib:
once_flag
, of the macro
ONCE_FLAG_INIT
, and the declaration of the function
call_once
, that are required by ISO C 23, are not provided.
To get them, import Gnulib module call_once
and include
<threads.h>
rather than <stdlib.h>
.
WEXITSTATUS
require an lvalue
argument on some platforms.
macOS 11.1.
POSIX specification:
Not in POSIX yet, but we expect it will be.
ISO C11 (latest free draft
http://www.open-std.org/jtc1/sc22/wg14/www/docs/n1570.pdf)
sections 7.23.
Gnulib module: stdnoreturn
Portability problems fixed by Gnulib:
<stdlib.h>
and
<process.h>
, on some platforms:
MSVC/clang.
Portability problems not fixed by Gnulib:
<stdnoreturn.h>
and the noreturn
macro are obsolescent in C23.
<stdnoreturn.h>
cannot be #included in C++ mode on some platforms:
FreeBSD 13.1.
<stdnoreturn.h>
should be #included before ‘_Noreturn’ is used.
_Noreturn
is a reserved word;
it might be a macro.
lint
is defined, standard headers define
_Noreturn
(and therefore noreturn
) to be a macro that
expands to the empty token sequence on some platforms:
Cygwin 2.5.1, FreeBSD 10.3.
noreturn
expands to the empty token
sequence, to avoid problems with standard headers that use noreturn
in combination with __attribute__
or __declspec
. Although
the resulting code operates correctly, the compiler is not informed whether
noreturn
functions do not return, so it may generate incorrect
warnings at compile-time, or code that is slightly less optimized. This
problem does not occur with _Noreturn
.
-Werror=old-style-declaration
requires _Noreturn
or noreturn
before the returned type
in a declaration, and therefore rejects valid but unusually-worded
declarations such as void _Noreturn foo (void);
.
POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/string.h.html
Gnulib module: string
Portability problems fixed by Gnulib:
NULL
macro that cannot be used in arbitrary
expressions:
NetBSD 5.0
Portability problems not fixed by Gnulib:
POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/strings.h.html
Gnulib module: strings
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/stropts.h.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/sys_ipc.h.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/sys_mman.h.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/sys_msg.h.html
Gnulib module: sys_msg
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/sys_resource.h.html
Gnulib module: sys_resource
Portability problems fixed by Gnulib:
RUSAGE_SELF
and
RUSAGE_CHILDREN
constants:
OpenVMS.
Portability problems not fixed by Gnulib:
RLIM_SAVED_CUR
or RLIM_SAVED_MAX
.
POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/sys_select.h.html
Gnulib module: sys_select
Portability problems fixed by Gnulib:
<sys/types.h>
to be included first.
<string.h>
before FD_ZERO
can be used—on some platforms:
AIX 7.1, Solaris 11.4.
Portability problems not fixed by Gnulib:
POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/sys_sem.h.html
Gnulib module: sys_sem
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/sys_shm.h.html
Gnulib module: sys_shm
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/sys_socket.h.html
Gnulib module: sys_socket
Portability problems fixed by Gnulib:
<sys/types.h>
to be included first.
socklen_t
on some platforms:
IRIX 6.5.
struct iovec
on some platforms:
OpenBSD 4.4.
SHUT_RD
, SHUT_WR
,
SHUT_RDWR
macros on some platforms, despite having the shutdown
functions:
emx+gcc.
struct sockaddr_storage
type does not have a member ss_family
on some platforms:
AIX 7.1.
CMSG_SPACE
and CMSG_LEN
macros are not provided on some
platforms:
OpenVMS.
SO_REUSEPORT
macro on some
platforms:
Minix 3.1.8, Solaris 10, Cygwin, mingw, MSVC 14.
Portability problems not fixed by Gnulib:
msg_control
and
msg_controllen
members of struct msghdr
on some
platforms. This can be detected by the absence of the
CMSG_FIRSTHDR
macro:
gnulib replacement header, old BSD
POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/sys_stat.h.html
Gnulib module: sys_stat
Portability problems fixed by Gnulib module sys_stat
:
mode_t
is not defined on some platforms:
MSVC 14.
S_IFMT
or S_IFIFO
, are missing on some
platforms.
S_ISBLK
, S_ISCHR
, S_ISDIR
, S_ISFIFO
,
S_ISLNK
, S_ISREG
, S_ISSOCK
are broken on some platforms.
S_ISDOOR
, that are not defined
on other platforms.
lstat
and mkdir
are not declared on some platforms:
mingw, MSVC 14.
UTIME_NOW
and UTIME_OMIT
are missing on some
platforms.
struct stat
does not include st_atim
,
st_mtim
, or st_ctim
members. Use the gnulib module
‘stat-time’ for accessors to portably get at subsecond resolution.
Portability problems fixed by Gnulib module sys_stat
, together with module windows-stat-inodes
:
st_ino
is always 0.
On platforms where off_t
is a 32-bit type, struct stat
cannot represent the size of files or block devices 2 GiB or lager
and may not work correctly on directories 2 GiB or larger.
Also, on platforms where ino_t
is a 32-bit type,
struct stat
cannot represent larger inode numbers.
See Large File Support, for how to address these problems.
See Avoiding the year 2038 problem, for portability issues with the
time_t
components of struct stat
.
Portability problems not fixed by Gnulib:
S_IFBLK
is missing on some platforms:
MSVC 14.
st_ino
is an array of three ino_t
values,
not a single value.
b
are known to represent the same file.
st_dev
and st_ino
values, even when st_ino
is nonzero:
st_dev
exceeds 255, or if a local
st_ino
exceeds 16777215.
st_size
contains bogus information for
symlinks; use the Gnulib module areadlink-with-size
for a
better way to get symlink contents.
To partially work around porting problems with Microsoft Windows and OpenVMS,
you can use the Gnulib same-inode
module to test whether two
struct stat
objects are known to represent the same file.
For example, psame_inode (&a, &b)
is true if the struct stat
objects a
and b
are known to represent the same file.
Another partial workaround is to compare other file metadata such as
st_mode
and st_mtime
on platforms where st_dev
and st_ino
not uniquely identify a file. However, this does
not work reliably on files whose metadata are being changed by other
programs, or where the metadata happen to be equal.
POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/sys_statvfs.h.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/sys_time.h.html
Gnulib module: sys_time
Portability problems fixed by Gnulib:
tv_sec
type that is
narrower than time_t
on some native Windows platforms:
mingw64 in 64-bit mode,
mingw64 in 32-bit mode when __MINGW_USE_VC2005_COMPAT
is defined,
MSVC 14 in 64-bit mode,
MSVC 14 in 32-bit mode when _USE_32BIT_TIME_T
is not defined.
See Avoiding the year 2038 problem, for portability issues with
time_t
and the time_t
component of struct timeval
.
Portability problems not fixed by Gnulib:
tv_sec
type that is
wider than time_t
:
OpenBSD 5.1 in 64-bit mode.
POSIX specification:
https://pubs.opengroup.org/onlinepubs/009695399/basedefs/sys/timeb.h.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/sys_times.h.html
Gnulib module: sys_times
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/sys_types.h.html
Gnulib module: sys_types
Portability problems fixed by Gnulib:
pid_t
is not defined on some platforms:
MSVC 14.
size_t
is not defined in this file on some platforms:
MSVC 14.
ssize_t
is not defined on some platforms:
MSVC 14.
mode_t
is not defined on some platforms:
MSVC 14.
major
, minor
, and
makedev
through this header; however, when
sys/sysmacros.h exists, that file should also be included to
avoid deprecation warnings from the versions in this header:
glibc 2.25.
See Avoiding the year 2038 problem, for portability issues with
time_t
.
Portability problems not fixed by Gnulib:
blksize_t
and suseconds_t
are signed integer types that are wider than long
:
glibc x32
This module, together with the module largefile
, also defines the type
off_t
to a 64-bit integer type on some platforms:
mingw, MSVC 14.
POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/sys_uio.h.html
Gnulib module: sys_uio
Portability problems fixed by Gnulib:
<sys/types.h>
to be
included first) on some platforms:
OpenBSD 4.4.
Portability problems not fixed by Gnulib:
POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/sys_un.h.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/sys_utsname.h.html
Gnulib module: sys_utsname
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/sys_wait.h.html
Gnulib module: sys_wait
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
WEXITSTATUS
require an lvalue
argument on some platforms.
macOS 11.1.
POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/syslog.h.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/tar.h.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/termios.h.html
Gnulib module: termios
Portability problems fixed by Gnulib:
pid_t
on all platforms:
glibc on some architectures, FreeBSD 6.4, OpenBSD 4.9, Cygwin 1.7.11.
Portability problems not fixed by Gnulib:
struct termios
, cc_t
, speed_t
, tcflag_t
are not defined on some platforms:
mingw, MSVC 14.
POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/tgmath.h.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
Defines the multithreading facility of ISO C11.
Gnulib module: threads-h
Portability problems fixed by Gnulib:
thrd_start_t
incorrectly on some platforms:
AIX 7.2.
TSS_DTOR_ITERATIONS
on some platforms:
AIX 7.2.
Portability problems not fixed by Gnulib:
thread_local
macro on some platforms:
POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/time.h.html
Gnulib module: time-h
Portability problems fixed by Gnulib:
TIME_UTC
is not defined on many platforms:
glibc 2.15, macOS 10.13, FreeBSD 11.0, NetBSD 7.1, OpenBSD 6.0, Minix 3.1.8, AIX 7.1, HP-UX 11.31, IRIX 6.5, Solaris 11.3, Cygwin 2.9, mingw, MSVC 14, Android 9.0.
NULL
macro that cannot be used in arbitrary
expressions:
NetBSD 5.0.
Portability problems fixed by the Gnulib module year2038
:
time_t
defaults to 32-bit but can be
changed to 64-bit, functions like stat
can fail with
errno == EOVERFLOW
when a 32-bit timestamp is out of range,
such as with a file timestamp in the far future or past:
glibc 2.34+ atop 32-bit x86 or ARM Linux.
See Avoiding the year 2038 problem.
Portability problems not fixed by Gnulib:
time_t
is always 32-bit, functions like
stat
can fail with errno == EOVERFLOW
when a timestamp
is out of range, such as with a file timestamp in the far future or
past; on other such platforms,
the functions silently return the low-order 32 bits of the correct
timestamp. These platforms will be obsolete when 32-bit time_t
rolls around, which will occur in 2038 for the typical case when
time_t
is signed.
See Avoiding the year 2038 problem.
tv_nsec
member of struct timespec
is not of type long
, but is of type long long
instead:
glibc x32
POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/trace.h.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
Defines the types char16_t
, char32_t
and declares the
functions mbrtoc16
, c16rtomb
, mbrtoc32
,
c32rtomb
.
Gnulib module: uchar or uchar-c23
Portability problems fixed by either Gnulib module uchar
or uchar-c23
:
Portability problems fixed by Gnulib module uchar-c23
:
char32_t
values may not be Unicode code points.
This is the case in ISO C 11 compliant but not ISO C 23 compliant
implementations.
Portability problems not fixed by Gnulib:
POSIX specification:
https://pubs.opengroup.org/onlinepubs/009695399/basedefs/ucontext.h.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/ulimit.h.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/unistd.h.html
Gnulib module: unistd
Portability problems fixed by Gnulib:
_exit
function is not declared in this file on some platforms:
mingw.
NULL
macro that cannot be used in arbitrary
expressions:
NetBSD 5.0
Portability problems not fixed by Gnulib:
POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/utime.h.html
Gnulib module: utime-h
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/utmpx.h.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
struct utmpx
field ut_user
,
older platforms have the field ut_name
.
struct utmpx
field ut_exit
does not exist on some platforms:
macOS, FreeBSD, AIX, Cygwin.
struct utmpx
field ut_session
does not exist
on some platforms:
macOS, FreeBSD, AIX, HP-UX, Cygwin.
struct utmpx
field ut_addr
or ut_addr_v6
or
ut_ss
does not exist on some platforms:
macOS, FreeBSD, AIX, IRIX, Solaris.
time_t
was historically 32 bits.
year2038
or
year2038-recommended
modules are used and the program is
configured without the --disable-year2038 option.
The readutmp
module works around this problem:
glibc 2.38 on 32-bit platforms like x86 and ARM where time_t
was historically 32 bits.
See Avoiding the year 2038 problem.
POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/wchar.h.html
Gnulib module: wchar
Portability problems fixed by Gnulib:
wint_t
is incorrect on some platforms:
mingw, MSVC 14.
NULL
macro that cannot be used in arbitrary
expressions:
NetBSD 5.0
Portability problems not fixed by Gnulib:
POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/wctype.h.html
Gnulib module: wctype-h
Portability problems fixed by Gnulib:
wint_t
is incorrect on some platforms:
mingw, MSVC 14.
isw*
are missing on some platforms:
FreeBSD 4.11.
iswblank
is declared but not defined on some platforms:
IRIX 6.5.30.
Portability problems not fixed by Gnulib:
POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/wordexp.h.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
This chapter describes which functions and function-like macros specified by ISO C (including ISO TS 18661-1) or POSIX are substituted by Gnulib, which portability pitfalls are fixed by Gnulib, and which (known) portability problems are not worked around by Gnulib.
The notation “Gnulib module: —” means that Gnulib does not provide a
module providing a substitute for the function. When the list
“Portability problems not fixed by Gnulib” is empty, such a module is
not needed: No portability problems are known. Otherwise, it indicates
that such a module would be useful but is not available: No one so far
found this function important enough to contribute a substitute for it.
If you need this particular function, you may write to
<bug-gnulib at gnu dot org>
.
FD_CLR
FD_ISSET
FD_SET
FD_ZERO
_Exit
_exit
_longjmp
_setjmp
_tolower
_toupper
a64l
abort
abs
accept
access
acos
acosf
acosh
acoshf
acoshl
acosl
aio_cancel
aio_error
aio_fsync
aio_read
aio_return
aio_suspend
aio_write
alarm
aligned_alloc
alphasort
asctime
asctime_r
asin
asinf
asinh
asinhf
asinhl
asinl
assert
atan
atan2
atan2f
atan2l
atanf
atanh
atanhf
atanhl
atanl
atexit
atof
atoi
atol
atoll
basename
bind
bsearch
btowc
c8rtomb
c16rtomb
c32rtomb
cabs
cabsf
cabsl
cacos
cacosf
cacosh
cacoshf
cacoshl
cacosl
calloc
call_once
canonicalize
canonicalizef
canonicalizel
carg
cargf
cargl
casin
casinf
casinh
casinhf
casinhl
casinl
catan
catanf
catanh
catanhf
catanhl
catanl
catclose
catgets
catopen
cbrt
cbrtf
cbrtl
ccos
ccosf
ccosh
ccoshf
ccoshl
ccosl
ceil
ceilf
ceill
cexp
cexpf
cexpl
cfgetispeed
cfgetospeed
cfsetispeed
cfsetospeed
chdir
chmod
chown
cimag
cimagf
cimagl
clearerr
clock
clock_getcpuclockid
clock_getres
clock_gettime
clock_nanosleep
clock_settime
clog
clogf
clogl
close
closedir
closelog
cnd_broadcast
cnd_destroy
cnd_init
cnd_signal
cnd_timedwait
cnd_wait
confstr
conj
conjf
conjl
connect
copysign
copysignf
copysignl
cos
cosf
cosh
coshf
coshl
cosl
cpow
cpowf
cpowl
cproj
cprojf
cprojl
creal
crealf
creall
creat
crypt
csin
csinf
csinh
csinhf
csinhl
csinl
csqrt
csqrtf
csqrtl
ctan
ctanf
ctanh
ctanhf
ctanhl
ctanl
ctermid
ctime
ctime_r
daddl
daylight
dbm_clearerr
dbm_close
dbm_delete
dbm_error
dbm_fetch
dbm_firstkey
dbm_nextkey
dbm_open
dbm_store
ddivl
difftime
dirfd
dirname
div
dlclose
dlerror
dlopen
dlsym
dmull
dprintf
drand48
dsubl
dup
dup2
duplocale
encrypt
endgrent
endhostent
endnetent
endprotoent
endpwent
endservent
endutxent
environ
erand48
erf
erfc
erfcf
erfcl
erff
erfl
errno
execl
execle
execlp
execv
execve
execvp
exit
exp
exp2
exp2f
exp2l
expf
expl
expm1
expm1f
expm1l
fabs
fabsf
fabsl
faccessat
fadd
faddl
fattach
fchdir
fchmod
fchmodat
fchown
fchownat
fclose
fcntl
fdatasync
fdetach
fdim
fdimf
fdiml
fdiv
fdivl
fdopen
fdopendir
feclearexcept
fegetenv
fegetexceptflag
fegetmode
fegetround
feholdexcept
feof
feraiseexcept
ferror
fesetenv
fesetexcept
fesetexceptflag
fesetmode
fesetround
fetestexcept
fetestexceptflag
feupdateenv
fexecve
fflush
ffs
fgetc
fgetpos
fgets
fgetwc
fgetws
fileno
flockfile
floor
floorf
floorl
fma
fmaf
fmal
fmax
fmaxf
fmaxl
fmaxmag
fmaxmagf
fmaxmagl
fmemopen
fmin
fminf
fminl
fminmag
fminmagf
fminmagl
fmod
fmodf
fmodl
fmtmsg
fmul
fmull
fnmatch
fopen
fork
fpathconf
fpclassify
fprintf
fputc
fputs
fputwc
fputws
fread
free
freeaddrinfo
freelocale
freopen
frexp
frexpf
frexpl
fromfp
fromfpf
fromfpl
fromfpx
fromfpxf
fromfpxl
fscanf
fseek
fseeko
fsetpos
fstat
fstatat
fstatvfs
fsub
fsubl
fsync
ftell
ftello
ftok
ftruncate
ftrylockfile
ftw
funlockfile
futimens
fwide
fwprintf
fwrite
fwscanf
gai_strerror
getaddrinfo
getc
getc_unlocked
getchar
getchar_unlocked
getcwd
getdate
getdate_err
getdelim
getegid
getenv
geteuid
getgid
getgrent
getgrgid
getgrgid_r
getgrnam
getgrnam_r
getgroups
gethostent
gethostid
gethostname
getitimer
getline
getlogin
getlogin_r
getmsg
getnameinfo
getnetbyaddr
getnetbyname
getnetent
getopt
getpayload
getpayloadf
getpayloadl
getpeername
getpgid
getpgrp
getpid
getpmsg
getppid
getpriority
getprotobyname
getprotobynumber
getprotoent
getpwent
getpwnam
getpwnam_r
getpwuid
getpwuid_r
getrlimit
getrusage
gets
getservbyname
getservbyport
getservent
getsid
getsockname
getsockopt
getsubopt
gettimeofday
getuid
getutxent
getutxid
getutxline
getwc
getwchar
glob
globfree
gmtime
gmtime_r
grantpt
hcreate
hdestroy
hsearch
htonl
htons
hypot
hypotf
hypotl
iconv
iconv_close
iconv_open
if_freenameindex
if_indextoname
if_nameindex
if_nametoindex
ilogb
ilogbf
ilogbl
imaxabs
imaxdiv
inet_addr
inet_ntoa
inet_ntop
inet_pton
initstate
insque
ioctl
isalnum
isalnum_l
isalpha
isalpha_l
isascii
isastream
isatty
isblank
isblank_l
iscntrl
iscntrl_l
isdigit
isdigit_l
isfinite
isgraph
isgraph_l
isgreater
isgreaterequal
isinf
isless
islessequal
islessgreater
islower
islower_l
isnan
isnormal
isprint
isprint_l
ispunct
ispunct_l
isspace
isspace_l
isunordered
isupper
isupper_l
iswalnum
iswalnum_l
iswalpha
iswalpha_l
iswblank
iswblank_l
iswcntrl
iswcntrl_l
iswctype
iswctype_l
iswdigit
iswdigit_l
iswgraph
iswgraph_l
iswlower
iswlower_l
iswprint
iswprint_l
iswpunct
iswpunct_l
iswspace
iswspace_l
iswupper
iswupper_l
iswxdigit
iswxdigit_l
isxdigit
isxdigit_l
j0
j1
jn
jrand48
kill
killpg
l64a
labs
lchown
lcong48
ldexp
ldexpf
ldexpl
ldiv
lfind
lgamma
lgammaf
lgammal
link
linkat
lio_listio
listen
llabs
lldiv
llogb
llogbf
llogbl
llrint
llrintf
llrintl
llround
llroundf
llroundl
localeconv
localtime
localtime_r
lockf
log
log10
log10f
log10l
log1p
log1pf
log1pl
log2
log2f
log2l
logb
logbf
logbl
logf
logl
longjmp
lrand48
lrint
lrintf
lrintl
lround
lroundf
lroundl
lsearch
lseek
lstat
malloc
mblen
mbrlen
mbrtoc8
mbrtoc16
mbrtoc32
mbrtowc
mbsinit
mbsnrtowcs
mbsrtowcs
mbstowcs
mbtowc
memccpy
memchr
memcmp
memcpy
memmove
memset
memset_explicit
mkdir
mkdirat
mkdtemp
mkfifo
mkfifoat
mknod
mknodat
mkstemp
mktime
mlock
mlockall
mmap
modf
modff
modfl
mprotect
mq_close
mq_getattr
mq_notify
mq_open
mq_receive
mq_send
mq_setattr
mq_timedreceive
mq_timedsend
mq_unlink
mrand48
msgctl
msgget
msgrcv
msgsnd
msync
mtx_destroy
mtx_init
mtx_lock
mtx_timedlock
mtx_trylock
mtx_unlock
munlock
munlockall
munmap
nan
nanf
nanl
nanosleep
nearbyint
nearbyintf
nearbyintl
newlocale
nextafter
nextafterf
nextafterl
nextdown
nextdownf
nextdownl
nexttoward
nexttowardf
nexttowardl
nextup
nextupf
nextupl
nftw
nice
nl_langinfo
nl_langinfo_l
nrand48
ntohl
ntohs
open
openat
opendir
openlog
open_memstream
open_wmemstream
optarg
opterr
optind
optopt
pathconf
pause
pclose
perror
pipe
poll
popen
posix_fadvise
posix_fallocate
posix_madvise
posix_mem_offset
posix_memalign
posix_openpt
posix_spawn
posix_spawn_file_actions_addclose
posix_spawn_file_actions_adddup2
posix_spawn_file_actions_addopen
posix_spawn_file_actions_destroy
posix_spawn_file_actions_init
posix_spawnattr_destroy
posix_spawnattr_getflags
posix_spawnattr_getpgroup
posix_spawnattr_getschedparam
posix_spawnattr_getschedpolicy
posix_spawnattr_getsigdefault
posix_spawnattr_getsigmask
posix_spawnattr_init
posix_spawnattr_setflags
posix_spawnattr_setpgroup
posix_spawnattr_setschedparam
posix_spawnattr_setschedpolicy
posix_spawnattr_setsigdefault
posix_spawnattr_setsigmask
posix_spawnp
posix_trace_attr_destroy
posix_trace_attr_getclockres
posix_trace_attr_getcreatetime
posix_trace_attr_getgenversion
posix_trace_attr_getinherited
posix_trace_attr_getlogfullpolicy
posix_trace_attr_getlogsize
posix_trace_attr_getmaxdatasize
posix_trace_attr_getmaxsystemeventsize
posix_trace_attr_getmaxusereventsize
posix_trace_attr_getname
posix_trace_attr_getstreamfullpolicy
posix_trace_attr_getstreamsize
posix_trace_attr_init
posix_trace_attr_setinherited
posix_trace_attr_setlogfullpolicy
posix_trace_attr_setlogsize
posix_trace_attr_setmaxdatasize
posix_trace_attr_setname
posix_trace_attr_setstreamfullpolicy
posix_trace_attr_setstreamsize
posix_trace_clear
posix_trace_close
posix_trace_create
posix_trace_create_withlog
posix_trace_event
posix_trace_eventid_equal
posix_trace_eventid_get_name
posix_trace_eventid_open
posix_trace_eventset_add
posix_trace_eventset_del
posix_trace_eventset_empty
posix_trace_eventset_fill
posix_trace_eventset_ismember
posix_trace_eventtypelist_getnext_id
posix_trace_eventtypelist_rewind
posix_trace_flush
posix_trace_get_attr
posix_trace_get_filter
posix_trace_get_status
posix_trace_getnext_event
posix_trace_open
posix_trace_rewind
posix_trace_set_filter
posix_trace_shutdown
posix_trace_start
posix_trace_stop
posix_trace_timedgetnext_event
posix_trace_trid_eventid_open
posix_trace_trygetnext_event
posix_typed_mem_get_info
posix_typed_mem_open
pow
powf
powl
pread
printf
pselect
psiginfo
psignal
pthread_atfork
pthread_attr_destroy
pthread_attr_getdetachstate
pthread_attr_getguardsize
pthread_attr_getinheritsched
pthread_attr_getschedparam
pthread_attr_getschedpolicy
pthread_attr_getscope
pthread_attr_getstack
pthread_attr_getstacksize
pthread_attr_init
pthread_attr_setdetachstate
pthread_attr_setguardsize
pthread_attr_setinheritsched
pthread_attr_setschedparam
pthread_attr_setschedpolicy
pthread_attr_setscope
pthread_attr_setstack
pthread_attr_setstacksize
pthread_barrier_destroy
pthread_barrier_init
pthread_barrier_wait
pthread_barrierattr_destroy
pthread_barrierattr_getpshared
pthread_barrierattr_init
pthread_barrierattr_setpshared
pthread_cancel
pthread_cleanup_pop
pthread_cleanup_push
pthread_cond_broadcast
pthread_cond_destroy
pthread_cond_init
pthread_cond_signal
pthread_cond_timedwait
pthread_cond_wait
pthread_condattr_destroy
pthread_condattr_getclock
pthread_condattr_getpshared
pthread_condattr_init
pthread_condattr_setclock
pthread_condattr_setpshared
pthread_create
pthread_detach
pthread_equal
pthread_exit
pthread_getconcurrency
pthread_getcpuclockid
pthread_getschedparam
pthread_getspecific
pthread_join
pthread_key_create
pthread_key_delete
pthread_kill
pthread_mutex_consistent
pthread_mutex_destroy
pthread_mutex_getprioceiling
pthread_mutex_init
pthread_mutex_lock
pthread_mutex_setprioceiling
pthread_mutex_timedlock
pthread_mutex_trylock
pthread_mutex_unlock
pthread_mutexattr_destroy
pthread_mutexattr_getprioceiling
pthread_mutexattr_getprotocol
pthread_mutexattr_getpshared
pthread_mutexattr_getrobust
pthread_mutexattr_gettype
pthread_mutexattr_init
pthread_mutexattr_setprioceiling
pthread_mutexattr_setprotocol
pthread_mutexattr_setpshared
pthread_mutexattr_setrobust
pthread_mutexattr_settype
pthread_once
pthread_rwlock_destroy
pthread_rwlock_init
pthread_rwlock_rdlock
pthread_rwlock_timedrdlock
pthread_rwlock_timedwrlock
pthread_rwlock_tryrdlock
pthread_rwlock_trywrlock
pthread_rwlock_unlock
pthread_rwlock_wrlock
pthread_rwlockattr_destroy
pthread_rwlockattr_getpshared
pthread_rwlockattr_init
pthread_rwlockattr_setpshared
pthread_self
pthread_setcancelstate
pthread_setcanceltype
pthread_setconcurrency
pthread_setschedparam
pthread_setschedprio
pthread_setspecific
pthread_sigmask
pthread_spin_destroy
pthread_spin_init
pthread_spin_lock
pthread_spin_trylock
pthread_spin_unlock
pthread_testcancel
ptsname
putc
putc_unlocked
putchar
putchar_unlocked
putenv
putmsg
putpmsg
puts
pututxline
putwc
putwchar
pwrite
qsort
quick_exit
raise
rand
rand_r
random
read
readdir
readdir_r
readlink
readlinkat
readv
realloc
realpath
recv
recvfrom
recvmsg
regcomp
regerror
regexec
regfree
remainder
remainderf
remainderl
remove
remque
remquo
remquof
remquol
rename
renameat
rewind
rewinddir
rint
rintf
rintl
rmdir
round
roundeven
roundevenf
roundevenl
roundf
roundl
scalbln
scalblnf
scalblnl
scalbn
scalbnf
scalbnl
scandir
scanf
sched_get_priority_max
sched_get_priority_min
sched_getparam
sched_getscheduler
sched_rr_get_interval
sched_setparam
sched_setscheduler
sched_yield
seed48
seekdir
select
sem_close
sem_destroy
sem_getvalue
sem_init
sem_open
sem_post
sem_timedwait
sem_trywait
sem_unlink
sem_wait
semctl
semget
semop
send
sendmsg
sendto
setbuf
setegid
setenv
seteuid
setgid
setgrent
sethostent
setitimer
setjmp
setkey
setlocale
setlogmask
setnetent
setpayload
setpayloadf
setpayloadl
setpayloadsig
setpayloadsigf
setpayloadsigl
setpgid
setpgrp
setpriority
setprotoent
setpwent
setregid
setreuid
setrlimit
setservent
setsid
setsockopt
setstate
setuid
setutxent
setvbuf
shm_open
shm_unlink
shmat
shmctl
shmdt
shmget
shutdown
sigaction
sigaddset
sigaltstack
sigdelset
sigemptyset
sigfillset
sighold
sigignore
siginterrupt
sigismember
siglongjmp
signal
signbit
signgam
sigpause
sigpending
sigprocmask
sigqueue
sigrelse
sigset
sigsetjmp
sigsuspend
sigtimedwait
sigwait
sigwaitinfo
sin
sinf
sinh
sinhf
sinhl
sinl
sleep
snprintf
sockatmark
socket
socketpair
sprintf
sqrt
sqrtf
sqrtl
srand
srand48
srandom
sscanf
stat
statvfs
stderr
stdin
stdout
stpcpy
stpncpy
strcasecmp
strcasecmp_l
strcat
strchr
strcmp
strcoll
strcoll_l
strcpy
strcspn
strdup
strerror
strerror_l
strerror_r
strfmon
strfmon_l
strfromd
strfromf
strfroml
strftime
strftime_l
strlen
strncasecmp
strncasecmp_l
strncat
strncmp
strncpy
strndup
strnlen
strpbrk
strptime
strrchr
strsignal
strspn
strstr
strtod
strtof
strtoimax
strtok
strtok_r
strtol
strtold
strtoll
strtoul
strtoull
strtoumax
strxfrm
strxfrm_l
swab
swprintf
swscanf
symlink
symlinkat
sync
sysconf
syslog
system
tan
tanf
tanh
tanhf
tanhl
tanl
tcdrain
tcflow
tcflush
tcgetattr
tcgetpgrp
tcgetsid
tcsendbreak
tcsetattr
tcsetpgrp
tdelete
telldir
tempnam
tfind
tgamma
tgammaf
tgammal
thrd_create
thrd_current
thrd_detach
thrd_equal
thrd_exit
thrd_join
thrd_sleep
thrd_yield
time
timegm
timer_create
timer_delete
timer_getoverrun
timer_gettime
timer_settime
times
timespec_getres
timezone
tmpfile
tmpnam
toascii
tolower
tolower_l
totalorder
totalorderf
totalorderl
totalordermag
totalordermagf
totalordermagl
toupper
toupper_l
towctrans
towctrans_l
towlower
towlower_l
towupper
towupper_l
trunc
truncate
truncf
truncl
tsearch
tss_create
tss_delete
tss_get
tss_set
ttyname
ttyname_r
twalk
tzname
tzset
ufromfp
ufromfpf
ufromfpl
ufromfpx
ufromfpxf
ufromfpxl
ulimit
umask
uname
ungetc
ungetwc
unlink
unlinkat
unlockpt
unsetenv
uselocale
utime
utimensat
utimes
va_arg
va_copy
va_end
va_start
vdprintf
vfprintf
vfscanf
vfwprintf
vfwscanf
vprintf
vscanf
vsnprintf
vsprintf
vsscanf
vswprintf
vswscanf
vwprintf
vwscanf
wait
waitid
waitpid
wcpcpy
wcpncpy
wcrtomb
wcscasecmp
wcscasecmp_l
wcscat
wcschr
wcscmp
wcscoll
wcscoll_l
wcscpy
wcscspn
wcsdup
wcsftime
wcslen
wcsncasecmp
wcsncasecmp_l
wcsncat
wcsncmp
wcsncpy
wcsnlen
wcsnrtombs
wcspbrk
wcsrchr
wcsrtombs
wcsspn
wcsstr
wcstod
wcstof
wcstoimax
wcstok
wcstol
wcstold
wcstoll
wcstombs
wcstoul
wcstoull
wcstoumax
wcswidth
wcsxfrm
wcsxfrm_l
wctob
wctomb
wctrans
wctrans_l
wctype
wctype_l
wcwidth
wmemchr
wmemcmp
wmemcpy
wmemmove
wmemset
wordexp
wordfree
wprintf
write
writev
wscanf
y0
y1
yn
FD_CLR
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/FD_CLR.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
FD_ISSET
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/FD_ISSET.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
FD_SET
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/FD_SET.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
FD_ZERO
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/FD_ZERO.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
_Exit
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/_Exit.html
Gnulib module: _Exit
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
_exit
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/_exit.html
Gnulib module: unistd
Portability problems fixed by Gnulib:
<stdlib.h>
)
on some platforms:
mingw, MSVC 14.
Portability problems not fixed by Gnulib:
_longjmp
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/_longjmp.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
Note: Despite its being removed from POSIX, in 2023 on all
systems which have _setjmp
, it is the fastest way to save the
registers but not the signal mask (up to 30 times faster than setjmp
on some systems).
_setjmp
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/_setjmp.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
Note: Despite its being removed from POSIX, in 2023 on all
systems which have _setjmp
, it is the fastest way to save the
registers but not the signal mask (up to 30 times faster than setjmp
on some systems).
_tolower
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/_tolower.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
tolower
instead.
_toupper
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/_toupper.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
toupper
instead.
a64l
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/a64l.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
abort
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/abort.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
abs
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/abs.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
accept
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/accept.html
Gnulib module: accept
Portability problems fixed by Gnulib:
accept
function cannot be used in calls to read
,
write
, and close
; you have to use recv
, send
,
closesocket
in these cases instead.
errno
, and WSAGetLastError
must be used
instead.
_HPUX_ALT_XOPEN_SOCKET_API
is not defined, this function behaves incorrectly because it is declared
to take a pointer to a 64-bit wide socklen_t
entity but in fact
considers it as a pointer to a 32-bit wide unsigned int
entity.
Portability problems not fixed by Gnulib:
socklen_t
type; in this case this function’s
third argument type is ‘int *’.
access
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/access.html
Gnulib module: access
Portability problems fixed by Gnulib:
X_OK
mode on some platforms:
MSVC 14.
Portability problems not fixed by Gnulib:
Other problems of this function:
stat
versus lstat
). If you need this option, use
the Gnulib module faccessat
with the AT_EACCESS
flag.
execlp
or execvp
. Nevertheless,
this function may return true for such files.
execlp
and execvp
search for files with the
suffixes .com
, .exe
, .bat
, .cmd
, when the
file with the given file name does not exist. Whereas cmd.exe
searches according to the PATHEXT
environment variable. This
function does not perform any search; it merely looks at the file with
the given file name.
acos
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/acos.html
Gnulib module: acos
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
acosf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/acosf.html
Gnulib module: acosf
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
acosh
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/acosh.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
acoshf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/acoshf.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
acoshl
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/acoshl.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
acosl
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/acosl.html
Gnulib module: acosl
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
aio_cancel
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/aio_cancel.html
Gnulib module: —
Portability problems fixed by Gnulib:
off_t
is a 32-bit type, this function may not
work correctly on files 2 GiB and larger. See Large File Support.
Portability problems not fixed by Gnulib:
aio_error
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/aio_error.html
Gnulib module: —
Portability problems fixed by Gnulib:
off_t
is a 32-bit type, this function may not
work correctly on files 2 GiB and larger. See Large File Support.
Portability problems not fixed by Gnulib:
aio_fsync
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/aio_fsync.html
Gnulib module: —
Portability problems fixed by Gnulib:
off_t
is a 32-bit type, this function may not
work correctly on files 2 GiB and larger. See Large File Support.
Portability problems not fixed by Gnulib:
aio_read
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/aio_read.html
Gnulib module: —
Portability problems fixed by Gnulib:
off_t
is a 32-bit type, this function may not
work correctly on files 2 GiB and larger. See Large File Support.
Portability problems not fixed by Gnulib:
aio_return
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/aio_return.html
Gnulib module: —
Portability problems fixed by Gnulib:
off_t
is a 32-bit type, this function may not
work correctly on files 2 GiB and larger. See Large File Support.
Portability problems not fixed by Gnulib:
aio_suspend
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/aio_suspend.html
Gnulib module: —
Portability problems fixed by Gnulib:
off_t
is a 32-bit type, this function may not
work correctly on files 2 GiB and larger. See Large File Support.
Portability problems not fixed by Gnulib:
aio_write
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/aio_write.html
Gnulib module: —
Portability problems fixed by Gnulib:
off_t
is a 32-bit type, this function may not
work correctly on files 2 GiB and larger. See Large File Support.
Portability problems not fixed by Gnulib:
alarm
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/alarm.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<io.h>
header on some platforms:
mingw (2012 or newer).
aligned_alloc
¶Documentation:
man aligned_alloc
Gnulib module: aligned_alloc
Portability problems fixed by Gnulib:
sizeof (void *)
on some platforms:
macOS 11.1, AIX 7.3.1.
Portability problems not fixed by Gnulib:
aligned_alloc
crashes if the requested size is
not a multiple of the alignment:
AddressSanitizer (gcc 11.2 or clang 13).
Gnulib has partial substitutes for aligned_alloc
that do not crash even if the AddressSanitizer bug is present:
alignalloc
provides a portable function
alignalloc
that is a near-substitute for glibc
aligned_alloc
, except that the result must be freed
with alignfree
rather than plain free
.
aligned-malloc
provides functions for
allocating and freeing blocks of suitably aligned memory.
pagealign_alloc
provides a similar API for
allocating and freeing blocks of memory aligned on a system page boundary.
alphasort
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/alphasort.html
Gnulib module: alphasort
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
const void *
on some platforms:
glibc 2.3.6, macOS 10.7, FreeBSD 6.0, NetBSD 7.1, OpenBSD 6.7.
void *
on some platforms:
AIX 5.1.
asctime
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/asctime.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
strftime
(or even sprintf
) instead.
asctime_r
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/asctime_r.html
Future POSIX removal:
https://www.austingroupbugs.net/view.php?id=1410
Gnulib module: extensions
Portability problems fixed by Gnulib:
_POSIX_PTHREAD_SEMANTICS
is not defined).
Portability problems not fixed by Gnulib:
strftime
(or even sprintf
) instead.
asin
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/asin.html
Gnulib module: asin
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
asinf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/asinf.html
Gnulib module: asinf
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
asinh
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/asinh.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
asinhf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/asinhf.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
asinhl
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/asinhl.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
asinl
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/asinl.html
Gnulib module: asinl
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
assert
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/assert.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
Extension: Gnulib offers a module ‘assert’ that allows the installer to disable assertions through a ‘configure’ option: ‘--disable-assert’.
atan
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/atan.html
Gnulib module: atan
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
atan2
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/atan2.html
Gnulib module: atan2
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
atan2f
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/atan2f.html
Gnulib module: atan2f
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
atan2l
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/atan2l.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
atanf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/atanf.html
Gnulib module: atanf
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
atanh
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/atanh.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
atanhf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/atanhf.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
atanhl
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/atanhl.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
atanl
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/atanl.html
Gnulib module: atanl
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
atexit
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/atexit.html
Gnulib module: atexit
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
atof
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/atof.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
atoi
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/atoi.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
atol
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/atol.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
atoll
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/atoll.html
Gnulib module: atoll
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
basename
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/basename.html
LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-basename-3.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
basename
: the POSIX
version and the GNU version.
basename
assumes file names in POSIX syntax; it does not work with file
names in Windows syntax.
The Gnulib module basename-lgpl
provides similar API, with a function
last_component
, that also works with Windows file names.
bind
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/bind.html
Gnulib module: bind
Portability problems fixed by Gnulib:
errno
, and WSAGetLastError
must be used
instead.
Portability problems not fixed by Gnulib:
bsearch
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/bsearch.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
btowc
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/btowc.html
Gnulib module: btowc
Portability problems fixed by Gnulib:
mbrtowc
and can return WEOF
:
glibc 2.35, MirOS BSD #10.
mbrtowc
on some platforms:
mingw.
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and
therefore cannot accommodate all Unicode characters.
However, the Gnulib function btoc32
, provided by Gnulib module
btoc32
, operates on 32-bit wide characters and therefore does not have
this limitation.
c8rtomb
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
c16rtomb
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
c32rtomb
¶Gnulib module: c32rtomb
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
cabs
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/cabs.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
cabsf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/cabsf.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
cabsl
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/cabsl.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
cacos
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/cacos.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
cacosf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/cacosf.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
cacosh
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/cacosh.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
cacoshf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/cacoshf.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
cacoshl
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/cacoshl.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
cacosl
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/cacosl.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
calloc
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/calloc.html
Gnulib module: calloc-posix
Portability problems fixed by Gnulib:
errno
to ENOMEM
on
some platforms:
mingw, MSVC 14.
calloc (n, s)
can succeed even if
multiplying n
by s
would exceed PTRDIFF_MAX
or
SIZE_MAX
. Although failing to check for exceeding
PTRDIFF_MAX
is arguably allowed by POSIX it can lead to
undefined behavior later, so calloc-posix
does not allow
going over the limit.
Extension: Gnulib provides a module ‘calloc-gnu’ that substitutes a
calloc
implementation that behaves more like the glibc implementation.
It fixes this portability problem:
calloc (0, s)
and calloc (n, 0)
return NULL
on success
on some platforms:
AIX 7.2.
call_once
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/Call-Once.html.
Gnulib module: call_once
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
canonicalize
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/FP-Bit-Twiddling.html.
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
canonicalizef
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/FP-Bit-Twiddling.html.
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
canonicalizel
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/FP-Bit-Twiddling.html.
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
carg
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/carg.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
cargf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/cargf.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
cargl
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/cargl.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
casin
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/casin.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
casinf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/casinf.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
casinh
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/casinh.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
casinhf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/casinhf.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
casinhl
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/casinhl.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
casinl
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/casinl.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
catan
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/catan.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
catanf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/catanf.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
catanh
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/catanh.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
catanhf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/catanhf.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
catanhl
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/catanhl.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
catanl
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/catanl.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
catclose
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/catclose.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
catgets
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/catgets.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
catopen
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/catopen.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
cbrt
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/cbrt.html
Gnulib module: cbrt
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
cbrtf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/cbrtf.html
Gnulib module: cbrtf
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
cbrtl
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/cbrtl.html
Gnulib module: cbrtl or cbrtl-ieee
Portability problems fixed by either Gnulib module cbrtl
or cbrtl-ieee
Portability problems fixed by Gnulib module cbrtl-ieee
:
Portability problems not fixed by Gnulib:
ccos
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ccos.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
ccosf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ccosf.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
ccosh
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ccosh.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
ccoshf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ccoshf.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
ccoshl
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ccoshl.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
ccosl
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ccosl.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
ceil
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ceil.html
Gnulib module: ceil or ceil-ieee
Portability problems fixed by either Gnulib module ceil
or ceil-ieee
:
Portability problems fixed by Gnulib module ceil-ieee
:
Portability problems not fixed by Gnulib:
ceilf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ceilf.html
Gnulib module: ceilf or ceilf-ieee
Portability problems fixed by either Gnulib module ceilf
or ceilf-ieee
:
Portability problems fixed by Gnulib module ceilf-ieee
:
Portability problems not fixed by Gnulib:
ceill
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ceill.html
Gnulib module: ceill or ceill-ieee
Portability problems fixed by either Gnulib module ceill
or ceill-ieee
:
Portability problems fixed by Gnulib module ceill-ieee
:
Portability problems not fixed by Gnulib:
cexp
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/cexp.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
cexpf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/cexpf.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
cexpl
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/cexpl.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
cfgetispeed
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/cfgetispeed.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
cfgetospeed
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/cfgetospeed.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
cfsetispeed
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/cfsetispeed.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
cfsetospeed
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/cfsetospeed.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
chdir
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/chdir.html
Gnulib module: chdir
Portability problems fixed by Gnulib:
<io.h>
or
<direct.h>
) on some platforms:
mingw, MSVC 14.
Portability problems not fixed by Gnulib:
chmod
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/chmod.html
Gnulib module: chmod
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
EACCES
when the failure is
due to lack of appropriate privileges (EPERM
), not to
search permission denied on the file name prefix (EACCES
):
Linux kernel 5.15 with glibc 2.35 and a CIFS v1 file system
(see https://bugs.gnu.org/65599).
chown
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/chown.html
Gnulib module: chown
Portability problems fixed by Gnulib:
chown("link-to-file/",uid,gid)
:
macOS 12.5, FreeBSD 7.2, AIX 7.3.1, Solaris 9.
lchown
:
some very old platforms.
ENOSYS
:
mingw, MSVC 14.
Portability problems not fixed by Gnulib:
EACCES
when the failure is
due to lack of appropriate privileges (EPERM
), not to
search permission denied on the file name prefix (EACCES
):
Linux kernel 5.15 with glibc 2.35 and a CIFS v1 file system
(see https://bugs.gnu.org/65599).
cimag
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/cimag.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
cimagf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/cimagf.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
cimagl
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/cimagl.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
clearerr
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/clearerr.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
clock
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/clock.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
clock_getcpuclockid
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/clock_getcpuclockid.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
clock_getres
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/clock_getres.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
clock_gettime
, i.e., the minimum distance between
differing timestamps. For example, on AIX 7.2 it returns 10
milliseconds even though the clock resolution is 1 microsecond.
Conversely, on GNU/Linux it typically returns 1 nanosecond even
though the clock resolution may be greater.
The Gnulib module gettime-res
is a partial substitute; it implements
the CLOCK_REALTIME
functionality of clock_getres
,
and fixes the too-high resolution bug of platforms like AIX 7.2.
clock_gettime
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/clock_gettime.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
tv_sec
field of the result
uninitialized on some platforms:
mingw in 32-bit mode.
The Gnulib modules gettime
and timespec_get
are partial
substitutes; they implement the CLOCK_REALTIME
functionality of
clock_gettime
.
clock_nanosleep
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/clock_nanosleep.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
clock_settime
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/clock_settime.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
clog
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/clog.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
clogf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/clogf.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
clogl
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/clogl.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
close
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/close.html
Gnulib module: close
Portability problems fixed by Gnulib:
<io.h>
)
on some platforms:
MSVC 14.
socket
and accept
do not return file descriptors that can be closed by close
.
Instead, closesocket
must be used.
Portability problems not fixed by Gnulib:
closedir
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/closedir.html
Gnulib module: closedir
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
closelog
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/closelog.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
cnd_broadcast
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/ISO-C-Condition-Variables.html.
Gnulib module: cnd
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
cnd_destroy
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/ISO-C-Condition-Variables.html.
Gnulib module: cnd
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
cnd_init
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/ISO-C-Condition-Variables.html.
Gnulib module: cnd
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
cnd_signal
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/ISO-C-Condition-Variables.html.
Gnulib module: cnd
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
cnd_timedwait
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/ISO-C-Condition-Variables.html.
Gnulib module: cnd
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
cnd_wait
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/ISO-C-Condition-Variables.html.
Gnulib module: cnd
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
confstr
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/confstr.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
conj
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/conj.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
conjf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/conjf.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
conjl
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/conjl.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
connect
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/connect.html
Gnulib module: connect
Portability problems fixed by Gnulib:
errno
, and WSAGetLastError
must be used
instead.
Portability problems not fixed by Gnulib:
copysign
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/copysign.html
Gnulib module: copysign
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
copysignf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/copysignf.html
Gnulib module: copysignf
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
copysignl
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/copysignl.html
Gnulib module: copysignl
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
cos
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/cos.html
Gnulib module: cos
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
cosf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/cosf.html
Gnulib module: cosf
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
cosh
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/cosh.html
Gnulib module: cosh
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
coshf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/coshf.html
Gnulib module: coshf
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
coshl
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/coshl.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
cosl
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/cosl.html
Gnulib module: cosl
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
cpow
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/cpow.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
cpowf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/cpowf.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
cpowl
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/cpowl.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
cproj
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/cproj.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
cprojf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/cprojf.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
cprojl
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/cprojl.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
creal
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/creal.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
crealf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/crealf.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
creall
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/creall.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
creat
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/creat.html
Gnulib module: creat
Portability problems fixed by Gnulib:
off_t
is a 32-bit type, creat
may not work
correctly with files 2 GiB and larger. See Large File Support.
Portability problems not fixed by Gnulib:
O_TEXT
mode. If you
need a file handle in O_BINARY
mode, you need to use the function
open
instead.
crypt
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/crypt.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<unistd.h>
(without -D_GNU_SOURCE
) on some platforms:
glibc (at least 2.11–2.13).
csin
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/csin.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
csinf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/csinf.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
csinh
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/csinh.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
csinhf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/csinhf.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
csinhl
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/csinhl.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
csinl
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/csinl.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
csqrt
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/csqrt.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
csqrtf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/csqrtf.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
csqrtl
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/csqrtl.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
ctan
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ctan.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
ctanf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ctanf.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
ctanh
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ctanh.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
ctanhf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ctanhf.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
ctanhl
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ctanhl.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
ctanl
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ctanl.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
ctermid
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ctermid.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
ctime
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ctime.html
Gnulib module: ctime
Portability problems fixed by Gnulib:
TZ
has been set by Cygwin.
Portability problems not fixed by Gnulib:
localtime_r
and strftime
(or even sprintf
) instead.
ctime
function need not be reentrant, and consequently is
not required to be thread safe. Implementations of ctime
typically write the timestamp into static buffer. If two threads
call ctime
at roughly the same time, you might end up with the
wrong date in one of the threads, or some undefined string. There is
a reentrant interface ctime_r
.
tzset
.
A more flexible function is strftime
. However, note that it is
locale dependent.
ctime_r
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ctime_r.html
Future POSIX removal:
https://www.austingroupbugs.net/view.php?id=1410
Gnulib module: extensions
Portability problems fixed by Gnulib:
_POSIX_PTHREAD_SEMANTICS
is not defined).
Portability problems not fixed by Gnulib:
localtime_r
and strftime
(or even sprintf
) instead.
ctime_r
takes a pre-allocated buffer and length of the buffer,
and returns NULL
on errors.
The input buffer should be at least 26 bytes in size. The output
string is locale-independent. However, years can have more than 4
digits if time_t
is sufficiently wide, so the length of the
required output buffer is not easy to determine. Increasing the
buffer size when ctime_r
returns NULL
is not necessarily
sufficient. The NULL
return value could mean some other error
condition, which will not go away by increasing the buffer size.
A more flexible function is strftime
. However, note that it is
locale dependent.
daddl
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/Misc-FP-Arithmetic.html.
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
daylight
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/daylight.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
tzset
.
A more portable way of getting the UTC offset is to use
strftime
with the %z
format. See strftime
.
dbm_clearerr
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/dbm_clearerr.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
dbm_close
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/dbm_close.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
dbm_delete
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/dbm_delete.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
dbm_error
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/dbm_error.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
dbm_fetch
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/dbm_fetch.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
dbm_firstkey
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/dbm_firstkey.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
dbm_nextkey
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/dbm_nextkey.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
dbm_open
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/dbm_open.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
dbm_store
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/dbm_store.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
ddivl
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/Misc-FP-Arithmetic.html.
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
difftime
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/difftime.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
dirfd
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/dirfd.html
Gnulib module: dirfd
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
dirfd
macro but no function, and the macro does not
work with an argument of type void *
, as a function would:
NetBSD 9.2.
dirname
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/dirname.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
dirname
assumes file names in POSIX syntax; it does not work with file
names in Windows syntax.
The Gnulib module dirname
provides similar API, with functions
dir_name
and mdir_name
, that also works with Windows
file names.
div
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/div.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
dlclose
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/dlclose.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
dlerror
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/dlerror.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
dlopen
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/dlopen.html
LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-dlopen-1.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
dlsym
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/dlsym.html
LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-dlsym-1.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
dmull
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/Misc-FP-Arithmetic.html.
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
dprintf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/dprintf.html
Gnulib module: dprintf or dprintf-posix or dprintf-gnu
Portability problems fixed by either Gnulib module dprintf
or dprintf-posix
or dprintf-gnu
:
Portability problems fixed by either Gnulib module dprintf-posix
or dprintf-gnu
:
w8
,
w16
, w32
, w64
, wf8
, wf16
, wf32
,
wf64
) on some platforms:
glibc, musl libc, macOS 12.5, FreeBSD 13.1, NetBSD 9.0, OpenBSD 7.2,
AIX 7.2, Solaris 11.4, Cygwin 2.9.0.
"%f"
, "%e"
, "%g"
of Infinity and NaN yields an
incorrect result on some platforms:
Solaris 11.4.
_FORTIFY_SOURCE >= 2
(set by default on Ubuntu),
Android, OpenBSD, macOS 11.1.
"%010f"
of NaN and Infinity yields an incorrect result (padded
with zeroes, or wrong capitalization) on some platforms:
Solaris 11.4.
"%#.0x"
or "%#.0X"
with a zero argument yields an
incorrect result (non-empty) on some platforms:
Mac OS X 10.6.
Portability problems fixed by Gnulib module dprintf-gnu
:
Portability problems not fixed by Gnulib:
%m
directive is not portable, use %s
mapped to an
argument of strerror(errno)
(or a version of strerror_r
)
instead.
errno
or the
stream error indicator on attempts to write to a read-only stream:
Cygwin 1.7.9.
drand48
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/drand48.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
dsubl
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/Misc-FP-Arithmetic.html.
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
dup
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/dup.html
Gnulib module: dup
Portability problems fixed by Gnulib:
<io.h>
)
on some platforms:
MSVC 14.
Portability problems not fixed by Gnulib:
dup2
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/dup2.html
Gnulib module: dup2
Portability problems fixed by Gnulib:
<io.h>
)
on some platforms:
MSVC 14.
EINVAL
when duplicating an fd to itself:
Android.
FD_CLOEXEC
flag when duplicating an fd
to itself on some platforms:
Haiku.
dup2 (1, 1)
on some platforms:
Cygwin 1.5.x.
-EBADF
instead of -1
on some platforms:
Linux releases between July 2008 and May 2009 (versions 2.6.27 to 2.6.29).
EMFILE
instead of EBADF
for
large targets, which interferes with using
dup2(fd,fd)==fd)
as the minimal EBADF
filter:
AIX 7.1, FreeBSD 6.1, Cygwin 1.5.
Portability problems not fixed by Gnulib:
duplocale
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/duplocale.html
Gnulib module: duplocale
Portability problems fixed by Gnulib:
LC_GLOBAL_LOCALE
is not supported on some platforms:
glibc 2.11, AIX 7.1.
LC_GLOBAL_LOCALE
, this function returns a wrong result
on some platforms:
NetBSD 7.1.
Portability problems not fixed by Gnulib:
locale_t
type is not defined
on some platforms:
z/OS.
LC_GLOBAL_LOCALE
, this function returns a wrong result
on some platforms:
Haiku.
encrypt
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/encrypt.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<unistd.h>
(without -D_GNU_SOURCE
) on some platforms:
glibc (at least 2.11–2.13).
endgrent
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/endgrent.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
endhostent
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/endhostent.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
endnetent
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/endnetent.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
endprotoent
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/endprotoent.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
endpwent
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/endpwent.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
endservent
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/endservent.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
endutxent
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/endutxent.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
environ
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/environ.html
Gnulib module: environ
Portability problems fixed by Gnulib:
extern char **environ;
to get the variable declared. This does not work any more, however, in shared libraries on macOS 11.1. Here is a workaround: Instead, one can use
#include <crt_externs.h> #define environ (*_NSGetEnviron())
This works at all versions of macOS.
-Wl,--disable-auto-import
is in use.
Portability problems not fixed by Gnulib:
environ
to clear all variables is not
portable; better is to assign environ
to one-element array
containing a NULL pointer. That said, an empty environment is not
portable either, as some systems may require particular environment
variables (such as PATH
) to be present in order to operate
consistently.
erand48
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/erand48.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
erf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/erf.html
Gnulib module: erf
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
erfc
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/erfc.html
Gnulib module: erfc
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
erfcf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/erfcf.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
erfcl
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/erfcl.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
erff
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/erff.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
erfl
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/erfl.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
errno
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/errno.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
errno
; their error code is
available through WSAGetLastError()
instead.
execl
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/execl.html
Gnulib module: execl
Portability problems fixed by Gnulib:
intptr_t
, not int
.
Note: The Gnulib replacement for this function is not async-safe, that is, it must not be invoked from a signal handler.
Portability problems not fixed by Gnulib:
execle
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/execle.html
Gnulib module: execle
Portability problems fixed by Gnulib:
intptr_t
, not int
.
Note: The Gnulib replacement for this function is not async-safe, that is, it must not be invoked from a signal handler.
Portability problems not fixed by Gnulib:
execlp
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/execlp.html
Gnulib module: execlp
Portability problems fixed by Gnulib:
intptr_t
, not int
.
Portability problems not fixed by Gnulib:
execv
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/execv.html
Gnulib module: execv
Portability problems fixed by Gnulib:
intptr_t
, not int
.
Note: The Gnulib replacement for this function is not async-safe, that is, it must not be invoked from a signal handler.
Portability problems not fixed by Gnulib:
execve
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/execve.html
Gnulib module: execve
Portability problems fixed by Gnulib:
intptr_t
, not int
.
Note: The Gnulib replacement for this function is not async-safe, that is, it must not be invoked from a signal handler.
Portability problems not fixed by Gnulib:
execvp
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/execvp.html
Gnulib module: execvp
Portability problems fixed by Gnulib:
intptr_t
, not int
.
Portability problems not fixed by Gnulib:
exit
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/exit.html
Gnulib module: stdlib
Portability problems fixed by Gnulib:
EXIT_SUCCESS
and EXIT_FAILURE
,
see stdlib.h.
Portability problems not fixed by Gnulib:
exp
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/exp.html
Gnulib module: exp
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
exp2
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/exp2.html
Gnulib module: exp2
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
exp2f
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/exp2f.html
Gnulib module: exp2f
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
exp2l
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/exp2l.html
Gnulib module: exp2l or exp2l-ieee
Portability problems fixed by either Gnulib module exp2l
or exp2l-ieee
:
Portability problems fixed by Gnulib module exp2l-ieee
:
Portability problems not fixed by Gnulib:
expf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/expf.html
Gnulib module: expf
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
expl
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/expl.html
Gnulib module: expl
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
expm1
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/expm1.html
Gnulib module: expm1 or expm1-ieee
Portability problems fixed by either Gnulib module expm1
or expm1-ieee
:
Portability problems fixed by Gnulib module expm1-ieee
:
Portability problems not fixed by Gnulib:
expm1f
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/expm1f.html
Gnulib module: expm1f or expm1f-ieee
Portability problems fixed by either Gnulib module expm1f
or expm1f-ieee
:
Portability problems fixed by Gnulib module expm1f-ieee
:
Portability problems not fixed by Gnulib:
expm1l
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/expm1l.html
Gnulib module: expm1l
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
fabs
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fabs.html
Gnulib module: fabs
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
fabsf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fabsf.html
Gnulib module: fabsf
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
fabsl
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fabsl.html
Gnulib module: fabsl
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
faccessat
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/faccessat.html
Gnulib module: faccessat
Portability problems fixed by Gnulib:
faccessat (dfd, "file/", amode, flag)
succeeds instead of failing when file is not a directory.
macOS 11.1.
Portability problems not fixed by Gnulib:
AT_SYMLINK_NOFOLLOW
flag,
which is supported by GNU faccessat
.
faccessat
can mishandle AT_EACCESS
after a process starts as root and then becomes non-root:
GNU/Linux with glibc 2.32.
Other problems of this function:
fadd
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/Misc-FP-Arithmetic.html.
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
faddl
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/Misc-FP-Arithmetic.html.
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
fattach
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fattach.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
fchdir
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fchdir.html
Gnulib module: fchdir
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
fchmod
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fchmod.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
EACCES
when the failure is
due to lack of appropriate privileges (EPERM
), not to
search permission denied on the file name prefix (EACCES
):
Linux kernel 5.15 with glibc 2.35 and a CIFS v1 file system
(see https://bugs.gnu.org/65599).
fchmodat
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fchmodat.html
Gnulib module: fchmodat
Portability problems fixed by Gnulib:
AT_SYMLINK_NOFOLLOW
flag,
this function fails with errno
set to ENOTSUP
,
even when the file is not a symbolic link:
GNU/Linux with glibc 2.31, Cygwin 2.9.
Portability problems not fixed by Gnulib:
AT_SYMLINK_NOFOLLOW
flag is specified,
this function can fail with errno
set to EMFILE
or ENFILE
,
and it fails with errno
set to EOPNOTSUPP
if the
/proc file system is not mounted:
GNU/Linux with glibc 2.34.
EACCES
when the failure is
due to lack of appropriate privileges (EPERM
), not to
search permission denied on the file name prefix (EACCES
):
Linux kernel 5.15 with glibc 2.35 and a CIFS v1 file system
(see https://bugs.gnu.org/65599).
fchown
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fchown.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
EACCES
when the failure is
due to lack of appropriate privileges (EPERM
), not to
search permission denied on the file name prefix (EACCES
):
Linux kernel 5.15 with glibc 2.35 and a CIFS v1 file system
(see https://bugs.gnu.org/65599).
fchownat
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fchownat.html
Gnulib module: fchownat
Portability problems fixed by Gnulib:
lchown
is unsupported, or fail altogether if
chown
is unsupported.
<sys/stat.h>
, not in <unistd.h>
,
on some platforms:
Android 4.3.
fchown(dir,"link-to-file/",uid,gid,flag)
:
Solaris 9.
AT_SYMLINK_NOFOLLOW
:
Linux kernel 2.6.17.
Portability problems not fixed by Gnulib:
EACCES
when the failure is
due to lack of appropriate privileges (EPERM
), not to
search permission denied on the file name prefix (EACCES
):
Linux kernel 5.15 with glibc 2.35 and a CIFS v1 file system
(see https://bugs.gnu.org/65599).
fclose
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fclose.html
Gnulib module: fclose
Portability problems fixed by Gnulib:
socket
and accept
followed by fdopen
do not return streams that can be closed by
fclose
.
Portability problems not fixed by Gnulib:
errno
upon failure.
fcntl
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fcntl.html
LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-fcntl-3.html
Gnulib module: fcntl
Portability problems fixed by Gnulib:
F_DUPFD_CLOEXEC
on some
platforms:
glibc with Linux kernels before 2.6.24,
Mac OS X 10.5, FreeBSD 6.0, NetBSD 5.0, OpenBSD 6.7, AIX 7.1, HP-UX 11,
IRIX 6.5, Solaris 11 2010-11, Cygwin 1.7.1.
Note that the gnulib replacement code is functional but not atomic.
F_DUPFD_CLOEXEC
action of this function does not set the
FD_CLOEXEC
flag on some platforms:
NetBSD 9.0.
F_DUPFD_CLOEXEC
action of this function sets the
FD_CLOEXEC
flag on the wrong file descriptor on some platforms:
Haiku.
F_DUPFD
action of this function does not reject
out-of-range targets properly on some platforms:
AIX 7.1, Cygwin 1.5.x, Haiku.
F_DUPFD
action of this function mistakenly clears
FD_CLOEXEC
on the source descriptor on some platforms:
Haiku.
Portability problems not fixed by Gnulib:
F_SETFD
,
F_GETFL
, F_SETFL
, F_GETOWN
, F_SETOWN
,
F_GETLK
, F_SETLK
, and F_SETLKW
on some platforms:
mingw, MSVC 14.
F_SETLK
and
F_SETLKW
fail with errno
set to different values on
different systems: EINVAL
on OpenIndiana (as suggested by the
POSIX 1003.1-2017 fcntl
specification), ENOLCK
on
GNU/Linux, and EOPNOTSUPP
on FreeBSD.
fdatasync
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fdatasync.html
Gnulib module: fdatasync
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
fdetach
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fdetach.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
fdim
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fdim.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
fdimf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fdimf.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
fdiml
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fdiml.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
fdiv
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/Misc-FP-Arithmetic.html.
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
fdivl
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/Misc-FP-Arithmetic.html.
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
fdopen
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fdopen.html
Gnulib module: fdopen
Portability problems fixed by Gnulib:
errno
upon failure.
Portability problems not fixed by Gnulib:
fdopendir
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fdopendir.html
Gnulib module: fdopendir
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
feclearexcept
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/feclearexcept.html
Gnulib module: fenv-exceptions-tracking-c99
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
fegetenv
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fegetenv.html
Gnulib module: fenv-environment
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
fegetexceptflag
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fegetexceptflag.html
Gnulib module: fenv-exceptions-state-c99
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
fegetmode
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/Control-Functions.html.
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
fegetround
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fegetround.html
Gnulib module: fenv-rounding
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
feholdexcept
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/feholdexcept.html
Gnulib module: fenv-environment
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
feof
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/feof.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
feraiseexcept
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/feraiseexcept.html
Gnulib module: fenv-exceptions-tracking-c99
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
ferror
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ferror.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
fesetenv
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fesetenv.html
Gnulib module: fenv-environment
Portability problems fixed by Gnulib:
FE_DFL_ENV
cannot be used because it leads to a link error
on some platforms:
NetBSD 9.3/hppa, NetBSD 9.3/sparc, Cygwin 2.9.0.
FE_DFL_ENV
argument, has no effect
on the x86 mxcsr
register and thus on floating-point operations
performed in the SSE unit on some platforms:
mingw 10.
Portability problems not fixed by Gnulib:
fesetexcept
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/Status-bit-operations.html.
Gnulib module: fenv-exceptions-tracking-c23
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
fesetexceptflag
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fesetexceptflag.html
Gnulib module: fenv-exceptions-state-c99
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
fesetmode
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/Control-Functions.html.
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
fesetround
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fesetround.html
Gnulib module: fenv-rounding
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
long double
operations on some platforms:
FreeBSD/arm64, NetBSD/sparc64, OpenBSD/mips64.
fetestexcept
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fetestexcept.html
Gnulib module: fenv-exceptions-tracking-c99
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
fetestexceptflag
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/Status-bit-operations.html.
Gnulib module: fenv-exceptions-state-c23
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
feupdateenv
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/feupdateenv.html
Gnulib module: fenv-environment
Portability problems fixed by Gnulib:
FE_DFL_ENV
on some platforms:
glibc 2.37/riscv64.
Portability problems not fixed by Gnulib:
fexecve
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fexecve.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
fflush
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fflush.html
Gnulib module: fflush
Portability problems fixed by Gnulib:
fflush
followed by fseek
or fseeko
, applied to an input
stream, should have the effect of positioning the underlying file descriptor.
It doesn’t do this on some platforms:
glibc 2.34, FreeBSD 13.0, and others.
fflush
on an input stream changes the position of the stream to the
end of the previous buffer, on some platforms: mingw, MSVC 14.
fflush
on an input stream right after ungetc
does not discard
the ungetc
buffer, on some platforms:
macOS 11.1, FreeBSD 6.0, NetBSD 9.0, OpenBSD 6.7, Cygwin 1.5.25-10.
Portability problems not fixed by Gnulib:
fflush
, ftell
, ftello
, fgetpos
behave incorrectly
on input streams that are opened in O_TEXT
mode and whose contents
contains Unix line terminators (LF), on some platforms: mingw, MSVC 14.
errno
upon failure.
MSVC_INVALID_PARAMETER_HANDLING
is
HAIRY_LIBRARY_HANDLING
or SANE_LIBRARY_HANDLING
,
on some platforms:
MSVC 14.
fflush
on an input stream right after ungetc
does not discard
the ungetc
buffer, on some platforms:
AIX 5.1, HP-UX 11, IRIX 6.5, Solaris 11 2010-11, mingw, MSVC 14.
ffs
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ffs.html
Gnulib module: ffs
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
fgetc
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fgetc.html
Gnulib module: stdio, nonblocking
Portability problems fixed by Gnulib module stdio
, together with module nonblocking
:
errno
being set to EINVAL
instead of EAGAIN
on
some platforms:
mingw, MSVC 14.
Portability problems not fixed by Gnulib:
feof
would return nonzero. However, on some systems this
function attempts to read from the underlying file descriptor even if
the stream’s end-of-file indicator is set. These systems include
glibc and default Solaris.
errno
upon failure.
MSVC_INVALID_PARAMETER_HANDLING
is
HAIRY_LIBRARY_HANDLING
or SANE_LIBRARY_HANDLING
,
on some platforms:
MSVC 14.
fgetpos
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fgetpos.html
Gnulib module: —
Portability problems fixed by Gnulib:
off_t
is a 32-bit type, this function may not
work correctly on files 2 GiB and larger. See Large File Support.
Portability problems not fixed by Gnulib:
fflush
, ftell
, ftello
, fgetpos
behave incorrectly
on input streams that are opened in O_TEXT
mode and whose contents
contains Unix line terminators (LF), on some platforms: mingw, MSVC 14.
fgets
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fgets.html
Gnulib module: stdio, nonblocking
Portability problems fixed by Gnulib module stdio
, together with module nonblocking
:
errno
being set to EINVAL
instead of EAGAIN
on
some platforms:
mingw, MSVC 14.
Portability problems not fixed by Gnulib:
feof
would return nonzero. However, on some systems this
function attempts to read from the underlying file descriptor even if
the stream’s end-of-file indicator is set. These systems include
glibc and default Solaris.
errno
upon failure.
fgetwc
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fgetwc.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
fgetws
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fgetws.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
fileno
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fileno.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
flockfile
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/flockfile.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
floor
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/floor.html
Gnulib module: floor or floor-ieee
Portability problems fixed by either Gnulib module floor
or floor-ieee
:
Portability problems fixed by Gnulib module floor-ieee
:
Portability problems not fixed by Gnulib:
floorf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/floorf.html
Gnulib module: floorf or floorf-ieee
Portability problems fixed by either Gnulib module floorf
or floorf-ieee
:
Portability problems fixed by Gnulib module floorf-ieee
:
Portability problems not fixed by Gnulib:
floorl
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/floorl.html
Gnulib module: floorl or floorl-ieee
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
fma
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fma.html
Gnulib module: fma
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
fmaf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fmaf.html
Gnulib module: fmaf
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
fmal
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fmal.html
Gnulib module: fmal
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
fmax
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fmax.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
fmaxf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fmaxf.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
fmaxl
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fmaxl.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
fmaxmag
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/Misc-FP-Arithmetic.html.
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
fmaxmagf
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/Misc-FP-Arithmetic.html.
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
fmaxmagl
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/Misc-FP-Arithmetic.html.
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
fmemopen
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fmemopen.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
fmin
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fmin.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
fminf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fminf.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
fminl
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fminl.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
fminmag
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/Misc-FP-Arithmetic.html.
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
fminmagf
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/Misc-FP-Arithmetic.html.
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
fminmagl
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/Misc-FP-Arithmetic.html.
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
fmod
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fmod.html
Gnulib module: fmod or fmod-ieee
Portability problems fixed by either Gnulib module fmod
or fmod-ieee
:
Portability problems fixed by Gnulib module fmod-ieee
:
Portability problems not fixed by Gnulib:
fmodf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fmodf.html
Gnulib module: fmodf or fmodf-ieee
Portability problems fixed by either Gnulib module fmodf
or fmodf-ieee
:
Portability problems fixed by Gnulib module fmodf-ieee
:
Portability problems not fixed by Gnulib:
fmodl
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fmodl.html
Gnulib module: fmodl or fmodl-ieee
Portability problems fixed by either Gnulib module fmodl
or fmodl-ieee
:
Portability problems fixed by Gnulib module fmodl-ieee
:
Portability problems not fixed by Gnulib:
fmtmsg
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fmtmsg.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
fmul
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/Misc-FP-Arithmetic.html.
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
fmull
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/Misc-FP-Arithmetic.html.
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
fnmatch
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fnmatch.html
LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-fnmatch-3.html
Documentation:
Gnulib module: fnmatch or fnmatch-gnu
Portability problems fixed by either Gnulib module fnmatch
or fnmatch-gnu
:
"?"
pattern character fails to match characters outside the
single-byte range on some platforms:
NetBSD 9.3,
Android 13.
"?"
pattern character fails to match characters outside the
Unicode BMP on some platforms:
Solaris 10, Cygwin 3.4.6,
MSVC,
32-bit AIX.
[!a-z]
) are not
supported on some platforms:
Solaris 11.4.
[:alnum:]
) inside
bracket expressions are not supported on some platforms:
FreeBSD 13.2,
NetBSD 9.3, Solaris 11 OpenIndiana, Cygwin 3.4.6.
[:alnum:]
) inside
bracket expressions fail to match characters outside the single-byte
range on some platforms:
Android 13.
[:cntrl:]
matches the empty string
on some platforms:
Solaris 11.4.
'['
on some platforms:
glibc 2.12,
macOS 12.5,
NetBSD 9.3.
Portability problems fixed by Gnulib module fnmatch-gnu
:
FNM_LEADING_DIR
and
FNM_CASEFOLD
on some platforms:
AIX 7.2, HP-UX 11.31, IRIX 6.5, Solaris 10.
FNM_CASEFOLD
does not work in many situations on some platforms:
NetBSD 9.3.
FNM_CASEFOLD
does not work for multibyte characters
consisting of more than one byte on some platforms:
Android 13.
FNM_EXTMATCH
on all non-glibc platforms:
musl libc, macOS 12.5, FreeBSD 13.2, NetBSD 9.3, OpenBSD 7.2, Minix 3.3, AIX 7.2, HP-UX 11.31, IRIX 6.5, Solaris 11.4, Cygwin 3.4.6, Android 13.
FNM_FILE_NAME
as an
alias of FNM_PATHNAME
on some platforms:
NetBSD 9.3, AIX 7.2, HP-UX 11.31, IRIX 6.5, Solaris 10.
Portability problems not fixed by Gnulib:
Note: Gnulib’s replacement function has some limitations:
"[[.ch.]]"
) or
equivalence classes (such as "[[=a=]]"
).
fopen
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fopen.html
Gnulib module: fopen or fopen-gnu
Portability problems fixed by either Gnulib module fopen
or fopen-gnu
:
off_t
is a 32-bit type, fopen
may not work
correctly with files 2 GiB and larger. See Large File Support.
Portability problems fixed by Gnulib module fopen-gnu
:
O_EXCL
), introduced in ISO C11,
on some platforms:
FreeBSD 8.2, NetBSD 6.1, OpenBSD 5.6, Minix 3.2, AIX 6.1, HP-UX 11.31, IRIX 6.5, Solaris 11.3, Cygwin 1.7.16 (2012), mingw, MSVC 14.
O_CLOEXEC
),
introduced into a future POSIX revision through
https://www.austingroupbugs.net/view.php?id=411, on some platforms:
glibc 2.6, macOS 11.1, FreeBSD 9.0, NetBSD 5.1, OpenBSD 5.6, Minix 3.2, AIX 7.2, HP-UX 11.31, IRIX 6.5, Solaris 11.3, Cygwin 1.7.16 (2012), mingw, MSVC 14.
Portability problems not fixed by Gnulib:
errno
upon failure.
'\n'
to CR/LF by default. Use the
"b"
flag if you need reliable binary I/O.
fstat
after open
and
fdopen
, rather than fopen
and fileno
.
fork
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fork.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
fork
followed by a call of the exec
family
(execl
, execlp
, execle
, execv
, execvp
,
or execve
) is less efficient than vfork
followed by the same
call. vfork
is a variant of fork
that has been introduced to
optimize the fork
/exec
pattern.
_spawnvp
instead.
fpathconf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fpathconf.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
fpclassify
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fpclassify.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
fprintf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fprintf.html
Gnulib module: fprintf-posix or fprintf-gnu or stdio, nonblocking, sigpipe
Portability problems fixed by either Gnulib module fprintf-posix
or fprintf-gnu
:
hh
, ll
,
j
, t
, z
) on some platforms:
AIX 5.1, HP-UX 11.23, IRIX 6.5, Solaris 9, Cygwin 1.5.24, old mingw, MSVC 9.
w8
,
w16
, w32
, w64
, wf8
, wf16
, wf32
,
wf64
) on some platforms:
glibc, musl libc, macOS 12.5, FreeBSD 13.1, NetBSD 9.0, OpenBSD 7.2,
AIX 7.2, HP-UX 11, IRIX 6.5, Solaris 11.4, Cygwin 2.9.0, mingw, MSVC 14.
"%f"
, "%e"
, "%g"
of Infinity and NaN yields an
incorrect result on some platforms:
AIX 5.2, Solaris 11.4, mingw, MSVC 14.
_FORTIFY_SOURCE >= 2
(set by default on Ubuntu),
Android, OpenBSD, macOS 11.1, MSVC 14.
"%2$s"
, on some platforms:
NetBSD 3.0, mingw, MSVC 14.
'
flag on some platforms:
NetBSD 3.0, Cygwin 1.5.24, mingw, MSVC 14.
"%010f"
of NaN and Infinity yields an incorrect result (padded
with zeroes, or wrong capitalization) on some platforms:
Mac OS X 10.5, FreeBSD 6.0, NetBSD 5.0, AIX 5.2, IRIX 6.5, Solaris 11.4, Cygwin 1.5.x, mingw, MSVC/clang.
"%#.0x"
or "%#.0X"
with a zero argument yields an
incorrect result (non-empty) on some platforms:
Mac OS X 10.6.
Portability problems fixed by Gnulib module fprintf-gnu
:
Portability problems fixed by Gnulib module stdio
or fprintf-posix
or fprintf-gnu
, together with module nonblocking
:
errno
being set to ENOSPC
instead of EAGAIN
on some
platforms:
mingw, MSVC 14.
Portability problems fixed by Gnulib module stdio
or fprintf-posix
or fprintf-gnu
, together with module sigpipe
:
SIGPIPE
handler, on some platforms:
mingw, MSVC 14.
Portability problems not fixed by Gnulib:
%m
directive is not portable, use %s
mapped to an
argument of strerror(errno)
(or a version of strerror_r
)
instead.
EOF
but
does not set the error flag for ferror
on some platforms:
glibc 2.13, cygwin 1.7.9.
fputc
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fputc.html
Gnulib module: stdio, nonblocking, sigpipe
Portability problems fixed by Gnulib module stdio
, together with module nonblocking
:
errno
being set to ENOSPC
instead of EAGAIN
on some
platforms:
mingw, MSVC 14.
Portability problems fixed by Gnulib module stdio
, together with module sigpipe
:
SIGPIPE
handler, on some platforms:
mingw, MSVC 14.
Portability problems not fixed by Gnulib:
errno
upon failure.
errno
or the
stream error indicator on attempts to write to a read-only stream:
Cygwin 1.7.9.
MSVC_INVALID_PARAMETER_HANDLING
is
HAIRY_LIBRARY_HANDLING
or SANE_LIBRARY_HANDLING
,
on some platforms:
MSVC 14.
fputs
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fputs.html
Gnulib module: stdio, nonblocking, sigpipe
Portability problems fixed by Gnulib module stdio
, together with module nonblocking
:
errno
being set to ENOSPC
instead of EAGAIN
on some
platforms:
mingw, MSVC 14.
Portability problems fixed by Gnulib module stdio
, together with module sigpipe
:
SIGPIPE
handler, on some platforms:
mingw, MSVC 14.
Portability problems not fixed by Gnulib:
errno
upon failure.
errno
or the
stream error indicator on attempts to write to a read-only stream:
Cygwin 1.7.9.
fputwc
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fputwc.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
fputws
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fputws.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
errno
or the
stream error indicator on attempts to write to a read-only stream:
Cygwin 1.7.9.
fread
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fread.html
Gnulib module: stdio, nonblocking
Portability problems fixed by Gnulib module stdio
, together with module nonblocking
:
errno
being set to EINVAL
instead of EAGAIN
on
some platforms:
mingw, MSVC 14.
Portability problems not fixed by Gnulib:
feof
would return nonzero. However, on some systems this
function attempts to read from the underlying file descriptor even if
the stream’s end-of-file indicator is set. These systems include
glibc and default Solaris.
errno
upon failure.
MSVC_INVALID_PARAMETER_HANDLING
is
HAIRY_LIBRARY_HANDLING
or SANE_LIBRARY_HANDLING
,
on some platforms:
MSVC 14.
free
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/free.html
Gnulib module: free-posix
Portability problems fixed by Gnulib:
errno
on many platforms:
glibc 2.32, Mac OS X, FreeBSD, NetBSD, OpenBSD 4.4, Minix, AIX, HP-UX, IRIX, Cygwin, mingw, MSVC.
Portability problems not fixed by Gnulib:
freeaddrinfo
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/freeaddrinfo.html
Gnulib module: getaddrinfo
Portability problems fixed by Gnulib:
<ws2tcpip.h>
rather than in
<netdb.h>
.
cdecl
.
Portability problems not fixed by Gnulib:
freelocale
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/freelocale.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
locale_t
type is not defined
on some platforms:
z/OS.
newlocale
invocations
on some platforms:
Haiku.
freopen
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/freopen.html
Gnulib module: freopen
Portability problems fixed by Gnulib:
stream
does not already have an open
file descriptor, freopen
returns the stream without opening
the file: glibc 2.24.
off_t
is a 32-bit type, freopen
may not work
correctly with files 2 GiB and larger. See Large File Support.
Portability problems not fixed by Gnulib:
errno
upon failure.
NULL
file name argument on some
platforms:
OpenBSD 4.9, AIX 7.1, HP-UX 11.23, IRIX 6.5, Solaris 10, mingw, MSVC 14.
fileno(f)
will be the same
before and after a call to freopen(name,mode,f)
. However, the
module freopen-safer
can at least protect stdin
, stdout
,
and stderr
.
frexp
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/frexp.html
Gnulib module: frexp
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
frexpf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/frexpf.html
Gnulib module: frexpf
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
frexpl
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/frexpl.html
Gnulib module: frexpl
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
fromfp
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/Rounding-Functions.html.
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
fromfpf
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/Rounding-Functions.html.
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
fromfpl
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/Rounding-Functions.html.
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
fromfpx
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/Rounding-Functions.html.
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
fromfpxf
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/Rounding-Functions.html.
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
fromfpxl
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/Rounding-Functions.html.
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
fscanf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fscanf.html
LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-fscanf.html
Gnulib module: stdio, nonblocking
Portability problems fixed by Gnulib module stdio
, together with module nonblocking
:
errno
being set to EINVAL
instead of EAGAIN
on
some platforms:
mingw, MSVC 14.
Portability problems not fixed by Gnulib:
feof
would return nonzero. However, on some systems this
function attempts to read from the underlying file descriptor even if
the stream’s end-of-file indicator is set. These systems include
glibc and default Solaris.
errno
upon failure.
hh
, ll
, j
,
t
, z
size specifiers.
fseek
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fseek.html
Gnulib module: fseek
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
errno
upon failure.
long
is a 32-bit type, fseek
does not work
correctly with files 2 GiB and larger, even when the AC_SYS_LARGEFILE
macro is used. The fix is to use fseeko
instead.
fseeko
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fseeko.html
Gnulib module: fseeko
Portability problems fixed by Gnulib:
fseeko
in <stdio.h>
is not enabled by default
on some platforms:
glibc 2.3.6.
off_t
is a 32-bit type, fseeko
does not work
correctly with files 2 GiB and larger. See Large File Support.
Portability problems not fixed by Gnulib:
fsetpos
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fsetpos.html
Gnulib module: —
Portability problems fixed by Gnulib:
off_t
is a 32-bit type, this function may not
work correctly on files 2 GiB and larger. See Large File Support.
Portability problems not fixed by Gnulib:
fstat
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fstat.html
Gnulib module: fstat
Portability problems fixed by Gnulib:
off_t
is a 32-bit type, fstat
may not correctly
report the size of files or block devices 2 GiB and larger..
See Large File Support.
tv_sec
value, tv_nsec
might be in the range
−1000000000..−1, representing a negative nanoseconds
offset from tv_sec
.
st_atime
, st_ctime
, st_mtime
fields are affected by
the current time zone and by the DST flag of the current time zone on some
platforms:
mingw, MSVC 14 (when the environment variable TZ
is set).
Portability problems not fixed by Gnulib:
struct stat
.
fstat
applied to the file descriptors 0 and 1, returns
different st_ino
values, even if standard input and standard output
are not redirected and refer to the same terminal.
fstatat
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fstatat.html
Gnulib module: fstatat
Portability problems fixed by Gnulib:
off_t
is a 32-bit type, fstatat
may
not correctly report the size of files or block devices larger than 2
GB. See Large File Support.
fstatat(fd,"file/",buf,flag)
succeeds instead of
failing with ENOTDIR
.
Solaris 9.
tv_sec
value, tv_nsec
might be in the range
−1000000000..−1, representing a negative nanoseconds
offset from tv_sec
.
Portability problems not fixed by Gnulib:
AT_EMPTY_PATH
is not used:
glibc 2.7, Linux 2.6.38.
struct stat
.
fstatvfs
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fstatvfs.html
Gnulib module: —
Portability problems fixed by Gnulib:
f_blocks
in ‘struct statvfs’ is a 32-bit
value, this function may not work correctly on files systems larger than
4 TiB. See Large File Support. This affects
glibc/Hurd, HP-UX 11, Solaris.
Portability problems not fixed by Gnulib:
fsub
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/Misc-FP-Arithmetic.html.
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
fsubl
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/Misc-FP-Arithmetic.html.
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
fsync
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fsync.html
Gnulib module: fsync
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
EBADF
on some platforms:
AIX 7.2, Cygwin 2.9.
ftell
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ftell.html
Gnulib module: ftell
Portability problems fixed by Gnulib:
putc
that followed a
getc
call that reached EOF on some platforms:
Solaris 11 2010-11.
ungetc
, throws away the ungetc
buffer, changes the stream’s file position, and returns the wrong position on
some platforms:
macOS 10.15 and newer.
Portability problems not fixed by Gnulib:
fseek
on some
platforms:
HP-UX 11.
fflush
, ftell
, ftello
, fgetpos
behave incorrectly
on input streams that are opened in O_TEXT
mode and whose contents
contains Unix line terminators (LF), on some platforms: mingw, MSVC 14.
long
is a 32-bit type, ftell
does not work
correctly with files 2 GiB and larger, even when the AC_SYS_LARGEFILE
macro is used. The fix is to use ftello
instead.
ftello
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ftello.html
Gnulib module: ftello
Portability problems fixed by Gnulib:
ftello
in <stdio.h>
is not enabled by default
on some platforms:
glibc 2.3.6.
putc
that followed a
getc
call that reached EOF on some platforms:
Solaris 11 2010-11.
ungetc
, throws away the ungetc
buffer, changes the stream’s file position, and returns the wrong position on
some platforms:
macOS 10.15 and newer.
off_t
is a 32-bit type, ftello
does not work
correctly with files 2 GiB and larger. See Large File Support.
Portability problems not fixed by Gnulib:
fseek
on some
platforms:
HP-UX 11.
fflush
, ftell
, ftello
, fgetpos
behave incorrectly
on input streams that are opened in O_TEXT
mode and whose contents
contains Unix line terminators (LF), on some platforms: mingw, MSVC 14.
ftok
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ftok.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
ftruncate
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ftruncate.html
Gnulib module: ftruncate
Portability problems fixed by Gnulib:
off_t
is a 32-bit type, this function may not
work correctly on files 2 GiB and larger. See Large File Support.
Portability problems not fixed by Gnulib:
ftrylockfile
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ftrylockfile.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
ftw
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ftw.html
Gnulib module: —
Portability problems fixed by Gnulib:
off_t
is a 32-bit type, this function may not
work correctly on files 2 GiB and larger. See Large File Support.
Portability problems not fixed by Gnulib:
fts
instead.
funlockfile
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/funlockfile.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
futimens
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/futimens.html
Gnulib module: futimens
Portability problems fixed by Gnulib:
ENOSYS
on some platforms:
Linux kernel 2.6.21.
UTIME_OMIT
or UTIME_NOW
, some systems require
the tv_sec
argument to be 0, and don’t necessarily handle all
file permissions in the manner required by POSIX:
Linux kernel 2.6.25.
UTIME_OMIT
for the modification time, but specifying
an access time, some systems fail to update the change time:
Linux kernel 2.6.32, macOS 11.1, NetBSD 9.0, Solaris 11.1.
AT_FDCWD
as the fd argument does not properly fail with
EBADF
on some systems:
glibc 2.11, musl libc, Solaris 11.
Portability problems not fixed by Gnulib:
ENOSYS
; the gnulib
module ‘utimens’ provides a more reliable interface fdutimens
.
stat
modifies the access time of
directories on some platforms, so utimensat
can only
effectively change directory modification time:
Cygwin 1.5.x.
fwide
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fwide.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
fwide
is not guaranteed to be able to change a file stream’s mode
to a different mode than the current one.
fwprintf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fwprintf.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
w8
,
w16
, w32
, w64
, wf8
, wf16
, wf32
,
wf64
) on some platforms:
glibc, musl libc, macOS 12.5, FreeBSD 13.1, NetBSD 9.0, OpenBSD 7.2,
AIX 7.2, HP-UX 11, Solaris 11.4, Cygwin 2.9.0, mingw, MSVC 14.
"%#.0x"
or "%#.0X"
with a zero argument yields an
incorrect result (non-empty) on some platforms:
Mac OS X 10.6.
%m
directive is not portable, use %s
mapped to an
argument of strerror(errno)
(or a version of strerror_r
)
instead.
%c
and %s
conversions may fail
on some platforms:
glibc 2.35.
errno
or the
stream error indicator on attempts to write to a read-only stream:
Cygwin 1.7.9.
fwrite
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fwrite.html
Gnulib module: stdio, nonblocking, sigpipe
Portability problems fixed by Gnulib module stdio
, together with module nonblocking
:
errno
being set to ENOSPC
instead of EAGAIN
on some
platforms:
mingw, MSVC 14.
Portability problems fixed by Gnulib module stdio
, together with module sigpipe
:
SIGPIPE
handler, on some platforms:
mingw, MSVC 14.
Portability problems not fixed by Gnulib:
errno
upon failure.
errno
or the
stream error indicator on attempts to write to a read-only stream:
Cygwin 1.7.9.
MSVC_INVALID_PARAMETER_HANDLING
is
HAIRY_LIBRARY_HANDLING
or SANE_LIBRARY_HANDLING
,
on some platforms:
MSVC 14.
fwscanf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fwscanf.html
LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-fwscanf.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
gai_strerror
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/gai_strerror.html
Gnulib module: getaddrinfo
Portability problems fixed by Gnulib:
<ws2tcpip.h>
on some
platforms:
mingw, MSVC 14.
char *
instead of const char *
on some platforms:
AIX 7.1, HP-UX 11, Solaris 9, mingw, MSVC 14.
Portability problems not fixed by Gnulib:
getaddrinfo
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getaddrinfo.html
Gnulib module: getaddrinfo
Portability problems fixed by Gnulib:
<ws2tcpip.h>
rather than in
<netdb.h>
.
cdecl
.
Portability problems not fixed by Gnulib:
getc
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getc.html
Gnulib module: stdio, nonblocking
Portability problems fixed by Gnulib module stdio
, together with module nonblocking
:
errno
being set to EINVAL
instead of EAGAIN
on
some platforms:
mingw, MSVC 14.
Portability problems not fixed by Gnulib:
feof
would return nonzero. However, on some systems this
function attempts to read from the underlying file descriptor even if
the stream’s end-of-file indicator is set. These systems include
glibc and default Solaris.
errno
upon failure.
getc_unlocked
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getc_unlocked.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getchar
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getchar.html
Gnulib module: stdio, nonblocking
Portability problems fixed by Gnulib module stdio
, together with module nonblocking
:
errno
being set to EINVAL
instead of EAGAIN
on
some platforms:
mingw, MSVC 14.
Portability problems not fixed by Gnulib:
feof
would return nonzero. However, on some systems this
function attempts to read from the underlying file descriptor even if
the stream’s end-of-file indicator is set. These systems include
glibc and default Solaris.
errno
upon failure.
getchar_unlocked
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getchar_unlocked.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getcwd
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getcwd.html
LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-getcwd.html
Gnulib module: getcwd or getcwd-lgpl
Portability problems fixed by either Gnulib module getcwd
or
getcwd-lgpl
:
<io.h>
or
<direct.h>
) on some platforms:
mingw, MSVC 14.
getcwd (NULL, n)
allocates memory for the result.
On some other platforms, this call is not allowed.
getcwd
uses int
instead of size_t
for the size argument when using non-standard
headers, and the declaration is missing from <unistd.h>
:
mingw, MSVC 14.
getcwd (buf, 0)
crashes:
MSVC 14.
getcwd (buf, 0)
fails with ERANGE
instead of the required EINVAL
:
mingw.
Portability problems fixed by Gnulib module getcwd
:
PATH_MAX
)
correctly on some platforms:
glibc on Linux 2.4.20, musl libc 1.2.2/powerpc64le, macOS 11.1, FreeBSD 6.4, NetBSD 9.0, OpenBSD 6.7, AIX 7.1.
Portability problems not fixed by Gnulib:
getcwd(NULL, nonzero)
, some platforms, such as glibc
or cygwin, allocate exactly nonzero
bytes and fail with
ERANGE
if it was not big enough, while other platforms, such as
FreeBSD, mingw, or MSVC 14, ignore the size argument and allocate whatever size
is necessary. If this call succeeds, an application cannot portably
access beyond the string length of the result.
getdate
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getdate.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
Gnulib provides a module parse-datetime
that contains a function
parse_datetime
that has similar functionality as the getdate
function.
getdate_err
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getdate_err.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getdelim
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getdelim.html
Gnulib module: getdelim
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getegid
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getegid.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getenv
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getenv.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
geteuid
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/geteuid.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getgid
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getgid.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getgrent
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getgrent.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getgrgid
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getgrgid.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getgrgid_r
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getgrgid_r.html
Gnulib module: extensions
Portability problems fixed by Gnulib:
_POSIX_PTHREAD_SEMANTICS
is not defined).
Portability problems not fixed by Gnulib:
getgrnam
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getgrnam.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getgrnam_r
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getgrnam_r.html
Gnulib module: extensions
Portability problems fixed by Gnulib:
_POSIX_PTHREAD_SEMANTICS
is not defined).
Portability problems not fixed by Gnulib:
getgroups
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getgroups.html
Gnulib module: getgroups
Portability problems fixed by Gnulib:
getgroups (0, NULL)
always fails. See macro
‘AC_FUNC_GETGROUPS’.
Portability problems not fixed by Gnulib:
fork
and exec
if
the parent process is multi-threaded.
The Gnulib module mgetgroups
provides a similar API.
gethostent
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/gethostent.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
gethostid
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/gethostid.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
gethostname
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/gethostname.html
Gnulib module: gethostname
Portability problems fixed by Gnulib:
<winsock2.h>
) on some platforms:
MSVC 14.
Portability problems not fixed by Gnulib:
int
instead of size_t
on some platforms:
Solaris 10.
EINVAL
, instead of returning a truncated host name.
getitimer
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getitimer.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
timer_gettime
instead.
getline
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getline.html
Gnulib module: getline
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getlogin
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getlogin.html
Gnulib module: getlogin
Portability problems fixed by Gnulib:
_POSIX
is defined on some platforms:
mingw.
Portability problems not fixed by Gnulib:
getlogin_r
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getlogin_r.html
Gnulib module: getlogin_r
Portability problems fixed by Gnulib:
_REENTRANT
is defined,
on some platforms:
HP-UX 11.
ERANGE
, when the buffer is not large enough, on some platforms:
macOS 11.1.
Portability problems not fixed by Gnulib:
_POSIX_PTHREAD_SEMANTICS
is not defined).
EINVAL
instead of ERANGE
when
the second argument is zero on some platforms:
HP-UX 11.31.
ENOMEM
instead of ERANGE
on
some platforms:
Haiku.
getmsg
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getmsg.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getnameinfo
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getnameinfo.html
Gnulib module: getaddrinfo
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getnetbyaddr
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getnetbyaddr.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getnetbyname
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getnetbyname.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getnetent
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getnetent.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getopt
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getopt.html
LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/libutil-getopt-3.html
Gnulib module: getopt-posix or getopt-gnu
The module getopt-gnu
has support for “long options” and for
“options that take optional arguments”. Compared to the API defined by POSIX,
it adds a header file <getopt.h>
and a function getopt_long
.
Portability problems fixed by either Gnulib module getopt-posix
or getopt-gnu
:
optind
after a missing required argument is wrong
on some platforms:
macOS 11.1, AIX 7.1, mingw.
Portability problems fixed by Gnulib module getopt-gnu
:
getopt
does not support the ‘+’ flag in the options
string on some platforms:
macOS 11.1, AIX 5.2, HP-UX 11, IRIX 6.5, Solaris 11 2010-11.
getopt
does not obey the combination of ‘+’
and ‘:’ flags in the options string on some platforms:
glibc 2.11.
getopt
does not obey the ‘-’ flag in the options
string when POSIXLY_CORRECT
is set on some platforms:
Cygwin 1.7.0.
getopt
does not support options with optional arguments
on some platforms:
macOS 11.1, OpenBSD 4.0, AIX 5.2, HP-UX 11, IRIX 6.5, Solaris 11 2010-11, Cygwin 1.5.x.
getopt_long
is missing on some platforms:
AIX 5.1, HP-UX 11, IRIX 6.5, Solaris 9, MSVC 14.
getopt_long
does not support abbreviated long options
where all disambiguations are equivalent on some platforms:
OpenBSD 5.0.
getopt_long_only
is missing on some platforms:
FreeBSD 5.2.1, NetBSD 9.0, AIX 5.1, HP-UX 11, IRIX 6.5, Solaris 9, mingw, MSVC 14.
W;
on some
platforms:
glibc 2.14.
Portability problems not fixed by Gnulib:
getopt
allows
mixing option and non-option arguments on the command line in any order.
Other implementations, such as the one in Cygwin, enforce strict POSIX
compliance: they require that the option arguments precede the non-option
arguments. This is something to watch out in your program’s
testsuite.
POSIXLY_CORRECT
, by setting
optind
to 0. Several BSD implementations provide optreset
,
causing a reset by setting it non-zero, although it does not
necessarily re-read POSIXLY_CORRECT
. Solaris getopt
does
not support either reset method, but does not maintain state that
needs the extra level of reset.
getpayload
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/FP-Bit-Twiddling.html.
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getpayloadf
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/FP-Bit-Twiddling.html.
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getpayloadl
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/FP-Bit-Twiddling.html.
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getpeername
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getpeername.html
Gnulib module: getpeername
Portability problems fixed by Gnulib:
errno
, and WSAGetLastError
must be used
instead.
_HPUX_ALT_XOPEN_SOCKET_API
is not defined, this function behaves incorrectly because it is declared
to take a pointer to a 64-bit wide socklen_t
entity but in fact
considers it as a pointer to a 32-bit wide unsigned int
entity.
Portability problems not fixed by Gnulib:
socklen_t
type; in this case this function’s
third argument type is ‘int *’.
getpgid
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getpgid.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getpgrp
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getpgrp.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getpid
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getpid.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getpmsg
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getpmsg.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getppid
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getppid.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getpriority
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getpriority.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getprotobyname
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getprotobyname.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getprotobynumber
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getprotobynumber.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getprotoent
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getprotoent.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getpwent
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getpwent.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getpwnam
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getpwnam.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getpwnam_r
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getpwnam_r.html
Gnulib module: extensions
Portability problems fixed by Gnulib:
_POSIX_PTHREAD_SEMANTICS
is not defined).
Portability problems not fixed by Gnulib:
getpwuid
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getpwuid.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
fork
and exec
if
the parent process is multi-threaded. Instead, use getpwuid_r
prior to forking.
getpwuid_r
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getpwuid_r.html
Gnulib module: extensions
Portability problems fixed by Gnulib:
_POSIX_PTHREAD_SEMANTICS
is not defined).
Portability problems not fixed by Gnulib:
fork
and exec
if
the parent process is multi-threaded. Use it prior to forking.
getrlimit
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getrlimit.html
LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-getrlimit-1.html
Gnulib module: —
Portability problems fixed by Gnulib:
rlim_t
is a 32-bit type, this function does not
allow to retrieve limits larger than 4 GiB and larger,
such as for RLIMIT_FSIZE. See Large File Support.
Portability problems not fixed by Gnulib:
getrusage
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getrusage.html
Gnulib module: getrusage
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
struct rusage
with
meaningful values.
gets
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/gets.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
fgets
instead.
errno
being set to EINVAL
instead of EAGAIN
on
some platforms:
mingw, MSVC 14.
errno
upon failure.
getservbyname
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getservbyname.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getservbyport
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getservbyport.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getservent
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getservent.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getsid
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getsid.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getsockname
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getsockname.html
Gnulib module: getsockname
Portability problems fixed by Gnulib:
errno
, and WSAGetLastError
must be used
instead.
_HPUX_ALT_XOPEN_SOCKET_API
is not defined, this function behaves incorrectly because it is declared
to take a pointer to a 64-bit wide socklen_t
entity but in fact
considers it as a pointer to a 32-bit wide unsigned int
entity.
Portability problems not fixed by Gnulib:
socklen_t
type; in this case this function’s
third argument type is ‘int *’.
getsockopt
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getsockopt.html
LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-getsockopt-1.html
Gnulib module: getsockopt
Portability problems fixed by Gnulib:
errno
, and WSAGetLastError
must be used
instead.
_HPUX_ALT_XOPEN_SOCKET_API
is not defined, this function behaves incorrectly because it is declared
to take a pointer to a 64-bit wide socklen_t
entity but in fact
considers it as a pointer to a 32-bit wide unsigned int
entity.
Portability problems not fixed by Gnulib:
socklen_t
type; in this case this function’s
fifth argument type is ‘int *’.
getsubopt
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getsubopt.html
Gnulib module: getsubopt
Portability problems fixed by Gnulib:
unistd.h
instead of
stdlib.h
on some platforms:
Cygwin 1.7.1.
Portability problems not fixed by Gnulib:
gettimeofday
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/gettimeofday.html
Gnulib module: gettimeofday
Portability problems fixed by Gnulib:
struct
timezone*
rather than void *
, making it an error to redeclare
the function with the POSIX signature:
glibc.
However, rather than penalize these systems with a replacement
function, gnulib defines GETTIMEOFDAY_TIMEZONE
to the
appropriate type for use in avoiding a compiler warning if assigning
gettimeofday
to a function pointer.
Portability problems not fixed by Gnulib:
gettimeofday
is not NULL
.
gettime
or timespec_get
instead.
(POSIX recommends to use the function clock_gettime
, but there is
no corresponding Gnulib module for it yet.)
getuid
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getuid.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getutxent
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getutxent.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getutxid
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getutxid.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getutxline
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getutxline.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getwc
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getwc.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
getwchar
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getwchar.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
glob
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/glob.html
Gnulib module: glob
Portability problems fixed by Gnulib:
off_t
is a 32-bit type, this function may not
work correctly on huge directories 2 GiB and larger.
See Large File Support.
Portability problems not fixed by Gnulib:
gl_flags
field.
globfree
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/globfree.html
Gnulib module: glob
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
gmtime
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/gmtime.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
gmtime_r
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/gmtime_r.html
Gnulib module: time_r
Portability problems fixed by Gnulib:
_REENTRANT
is defined,
on some platforms:
HP-UX 11.
Portability problems not fixed by Gnulib:
grantpt
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/grantpt.html
Gnulib module: grantpt
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
hcreate
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/hcreate.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
hdestroy
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/hdestroy.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
hsearch
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/hsearch.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
htonl
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/htonl.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
htons
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/htons.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
hypot
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/hypot.html
Gnulib module: hypot or hypot-ieee
Portability problems fixed by either Gnulib module hypot
or hypot-ieee
:
Portability problems fixed by Gnulib module hypot-ieee
:
Portability problems not fixed by Gnulib:
hypotf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/hypotf.html
Gnulib module: hypotf or hypotf-ieee
Portability problems fixed by either Gnulib module hypotf
or hypotf-ieee
:
Portability problems fixed by Gnulib module hypot-ieee
:
Portability problems not fixed by Gnulib:
hypotl
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/hypotl.html
Gnulib module: hypotl or hypotl-ieee
Portability problems fixed by either Gnulib module hypotl
or hypotl-ieee
:
Portability problems fixed by Gnulib module hypotl-ieee
:
Portability problems not fixed by Gnulib:
iconv
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/iconv.html
Gnulib module: iconv
Portability problems fixed by Gnulib:
Portability problems handled by Gnulib
(in the sense that HAVE_ICONV
does not get defined if the system’s
iconv
function has this problem):
Portability problems not fixed by Gnulib:
iconv
encounters an input character that is valid but that
cannot be converted to the output character set, glibc’s and GNU libiconv’s
iconv
stop the conversion. Some other implementations put an
implementation-defined character into the output buffer.
Gnulib provides higher-level facilities striconv
and striconveh
(wrappers around iconv
) that deal with conversion errors in a platform
independent way.
iconv_close
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/iconv_close.html
Gnulib module: iconv
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
iconv_open
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/iconv_open.html
Gnulib module: iconv, iconv_open, iconv_open-utf
Portability problems fixed by either Gnulib module iconv
or iconv_open
:
Portability problems handled by either Gnulib module iconv
or iconv_open
(in the sense that HAVE_ICONV
does not get defined if the system’s
iconv_open
function has this problem):
Portability problems fixed by Gnulib module iconv_open
:
Portability problems fixed by Gnulib module iconv_open-utf
:
Portability problems not fixed by Gnulib:
striconveh
(a wrapper around iconv
) that deals with
this problem.
if_freenameindex
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/if_freenameindex.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
if_indextoname
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/if_indextoname.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
if_nameindex
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/if_nameindex.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
if_nametoindex
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/if_nametoindex.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
ilogb
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ilogb.html
Gnulib module: ilogb
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
ilogbf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ilogbf.html
Gnulib module: ilogbf
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
ilogbl
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ilogbl.html
Gnulib module: ilogbl
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
imaxabs
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/imaxabs.html
Gnulib module: imaxabs
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
imaxdiv
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/imaxdiv.html
Gnulib module: imaxdiv
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
inet_addr
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/inet_addr.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
inet_pton
instead.
inet_ntoa
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/inet_ntoa.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
inet_ntop
instead.
inet_ntoa
function need not be reentrant, and consequently
is not required to be thread safe. Implementations of
inet_ntoa
typically write the timestamp into static buffer.
If two threads call inet_ntoa
at roughly the same time, you
might end up with the wrong date in one of the threads, or some
undefined string.
Note: inet_ntoa
is specific for IPv4 addresses.
A protocol independent function is inet_ntop
.
inet_ntop
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/inet_ntop.html
Gnulib module: inet_ntop
Portability problems fixed by Gnulib:
<netdb.h>
instead of <arpa/inet.h>
on some platforms:
NonStop Kernel.
<ws2tcpip.h>
, with a POSIX incompatible
declaration, on some platforms:
MSVC 14 on Windows >= Vista.
Portability problems not fixed by Gnulib:
size_t
instead of
socklen_t
on some platforms:
Solaris 10.
inet_pton
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/inet_pton.html
Gnulib module: inet_pton
Portability problems fixed by Gnulib:
<netdb.h>
instead of <arpa/inet.h>
on some platforms:
NonStop Kernel.
<ws2tcpip.h>
, with a POSIX incompatible
declaration, on some platforms:
MSVC 14 on Windows >= Vista.
Portability problems not fixed by Gnulib:
initstate
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/initstate.html
Gnulib module: random
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
unsigned long
instead of unsigned int
on
some platforms:
MidnightBSD 2.0.
long
instead of size_t
on some platforms:
MidnightBSD 2.0.
insque
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/insque.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
ioctl
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ioctl.html
LSB specification:
Gnulib module: ioctl
Portability problems fixed by Gnulib:
ioctl
is called
ioctlsocket
, and error codes from this function are not placed in
errno
, and WSAGetLastError
must be used instead.
unsigned long
rather than int
on some platforms:
glibc 2.26, macOS 11.1, FreeBSD 13.0, NetBSD 9.0, OpenBSD 6.7, Haiku 2017.
Portability problems not fixed by Gnulib:
ioctl
requests are platform and hardware specific.
isalnum
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/isalnum.html
Gnulib module: ctype
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
Note: This function’s behaviour depends on the locale, but does not support
the multibyte characters that occur in strings in locales with
MB_CUR_MAX > 1
(this includes all the common UTF-8 locales).
There are five alternative APIs:
c_isalnum
This function operates in a locale independent way and returns true only for ASCII characters. It is provided by the Gnulib module ‘c-ctype’.
iswalnum
This function operates in a locale dependent way, on wide characters. In
order to use it, you first have to convert from multibyte to wide characters,
using the mbrtowc
function. It is provided by the Gnulib module
‘wctype’.
c32isalnum
This function operates in a locale dependent way, on 32-bit wide characters.
In order to use it, you first have to convert from multibyte to 32-bit wide
characters, using the mbrtoc32
function. It is provided by the
Gnulib module ‘c32isalnum’.
mb_isalnum
This function operates in a locale dependent way, on multibyte characters. It is provided by the Gnulib module ‘mbchar’.
uc_is_alnum
This function operates in a locale independent way, on Unicode characters. It is provided by the Gnulib module ‘unictype/ctype-alnum’.
isalnum_l
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/isalnum_l.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
isalpha
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/isalpha.html
Gnulib module: ctype
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
Note: This function’s behaviour depends on the locale, but does not support
the multibyte characters that occur in strings in locales with
MB_CUR_MAX > 1
(this includes all the common UTF-8 locales).
There are five alternative APIs:
c_isalpha
This function operates in a locale independent way and returns true only for ASCII characters. It is provided by the Gnulib module ‘c-ctype’.
iswalpha
This function operates in a locale dependent way, on wide characters. In
order to use it, you first have to convert from multibyte to wide characters,
using the mbrtowc
function. It is provided by the Gnulib module
‘wctype’.
c32isalpha
This function operates in a locale dependent way, on 32-bit wide characters.
In order to use it, you first have to convert from multibyte to 32-bit wide
characters, using the mbrtoc32
function. It is provided by the
Gnulib module ‘c32isalpha’.
mb_isalpha
This function operates in a locale dependent way, on multibyte characters. It is provided by the Gnulib module ‘mbchar’.
uc_is_alpha
This function operates in a locale independent way, on Unicode characters. It is provided by the Gnulib module ‘unictype/ctype-alpha’.
isalpha_l
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/isalpha_l.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
isascii
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/isascii.html
Gnulib module: ctype
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
Note: This function’s behaviour depends on the locale, but requires special
handling for the multibyte characters that occur in strings in locales with
MB_CUR_MAX > 1
(this includes all the common UTF-8 locales).
There are two alternative APIs:
c_isascii
This function operates in a locale independent way and returns true only for ASCII characters. It is provided by the Gnulib module ‘c-ctype’.
mb_isascii
This function operates in a locale dependent way, on multibyte characters. It is provided by the Gnulib module ‘mbchar’.
isastream
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/isastream.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
isatty
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/isatty.html
Gnulib module: isatty
Portability problems fixed by Gnulib:
<io.h>
)
on some platforms:
MSVC 14.
Portability problems not fixed by Gnulib:
isblank
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/isblank.html
Gnulib module: isblank
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
Note: This function’s behaviour depends on the locale, but does not support
the multibyte characters that occur in strings in locales with
MB_CUR_MAX > 1
(this includes all the common UTF-8 locales).
There are five alternative APIs:
c_isblank
This function operates in a locale independent way and returns true only for ASCII characters. It is provided by the Gnulib module ‘c-ctype’.
iswblank
This function operates in a locale dependent way, on wide characters. In
order to use it, you first have to convert from multibyte to wide characters,
using the mbrtowc
function. It is provided by the Gnulib module
‘wctype’.
c32isblank
This function operates in a locale dependent way, on 32-bit wide characters.
In order to use it, you first have to convert from multibyte to 32-bit wide
characters, using the mbrtoc32
function. It is provided by the
Gnulib module ‘c32isblank’.
mb_isblank
This function operates in a locale dependent way, on multibyte characters. It is provided by the Gnulib module ‘mbchar’.
uc_is_blank
This function operates in a locale independent way, on Unicode characters. It is provided by the Gnulib module ‘unictype/ctype-blank’.
isblank_l
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/isblank_l.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
iscntrl
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/iscntrl.html
Gnulib module: ctype
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
Note: This function’s behaviour depends on the locale, but does not support
the multibyte characters that occur in strings in locales with
MB_CUR_MAX > 1
(this includes all the common UTF-8 locales).
There are five alternative APIs:
c_iscntrl
This function operates in a locale independent way and returns true only for ASCII characters. It is provided by the Gnulib module ‘c-ctype’.
iswcntrl
This function operates in a locale dependent way, on wide characters. In
order to use it, you first have to convert from multibyte to wide characters,
using the mbrtowc
function. It is provided by the Gnulib module
‘wctype’.
c32iscntrl
This function operates in a locale dependent way, on 32-bit wide characters.
In order to use it, you first have to convert from multibyte to 32-bit wide
characters, using the mbrtoc32
function. It is provided by the
Gnulib module ‘c32iscntrl’.
mb_iscntrl
This function operates in a locale dependent way, on multibyte characters. It is provided by the Gnulib module ‘mbchar’.
uc_is_cntrl
This function operates in a locale independent way, on Unicode characters. It is provided by the Gnulib module ‘unictype/ctype-cntrl’.
iscntrl_l
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/iscntrl_l.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
isdigit
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/isdigit.html
Gnulib module: ctype
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
Note: This function’s behaviour depends on the locale, but does not support
the multibyte characters that occur in strings in locales with
MB_CUR_MAX > 1
(this includes all the common UTF-8 locales).
There are five alternative APIs:
c_isdigit
This function operates in a locale independent way and returns true only for ASCII characters. It is provided by the Gnulib module ‘c-ctype’.
iswdigit
This function operates in a locale dependent way, on wide characters. In
order to use it, you first have to convert from multibyte to wide characters,
using the mbrtowc
function. It is provided by the Gnulib module
‘wctype’.
c32isdigit
This function operates in a locale dependent way, on 32-bit wide characters.
In order to use it, you first have to convert from multibyte to 32-bit wide
characters, using the mbrtoc32
function. It is provided by the
Gnulib module ‘c32isdigit’.
mb_isdigit
This function operates in a locale dependent way, on multibyte characters. It is provided by the Gnulib module ‘mbchar’.
uc_is_digit
This function operates in a locale independent way, on Unicode characters. It is provided by the Gnulib module ‘unictype/ctype-digit’.
isdigit_l
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/isdigit_l.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
isfinite
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/isfinite.html
Gnulib module: isfinite
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
isfinite
raises an
exception given a signaling NaN operand.
isgraph
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/isgraph.html
Gnulib module: ctype
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
Note: This function’s behaviour depends on the locale, but does not support
the multibyte characters that occur in strings in locales with
MB_CUR_MAX > 1
(this includes all the common UTF-8 locales).
There are five alternative APIs:
c_isgraph
This function operates in a locale independent way and returns true only for ASCII characters. It is provided by the Gnulib module ‘c-ctype’.
iswgraph
This function operates in a locale dependent way, on wide characters. In
order to use it, you first have to convert from multibyte to wide characters,
using the mbrtowc
function. It is provided by the Gnulib module
‘wctype’.
c32isgraph
This function operates in a locale dependent way, on 32-bit wide characters.
In order to use it, you first have to convert from multibyte to 32-bit wide
characters, using the mbrtoc32
function. It is provided by the
Gnulib module ‘c32isgraph’.
mb_isgraph
This function operates in a locale dependent way, on multibyte characters. It is provided by the Gnulib module ‘mbchar’.
uc_is_graph
This function operates in a locale independent way, on Unicode characters. It is provided by the Gnulib module ‘unictype/ctype-graph’.
isgraph_l
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/isgraph_l.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
isgreater
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/isgreater.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
isgreaterequal
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/isgreaterequal.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
isinf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/isinf.html
Gnulib module: isinf
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
isless
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/isless.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
islessequal
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/islessequal.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
islessgreater
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/islessgreater.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
islower
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/islower.html
Gnulib module: ctype
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
Note: This function’s behaviour depends on the locale, but does not support
the multibyte characters that occur in strings in locales with
MB_CUR_MAX > 1
(this includes all the common UTF-8 locales).
There are five alternative APIs:
c_islower
This function operates in a locale independent way and returns true only for ASCII characters. It is provided by the Gnulib module ‘c-ctype’.
iswlower
This function operates in a locale dependent way, on wide characters. In
order to use it, you first have to convert from multibyte to wide characters,
using the mbrtowc
function. It is provided by the Gnulib module
‘wctype’.
c32islower
This function operates in a locale dependent way, on 32-bit wide characters.
In order to use it, you first have to convert from multibyte to 32-bit wide
characters, using the mbrtoc32
function. It is provided by the
Gnulib module ‘c32islower’.
mb_islower
This function operates in a locale dependent way, on multibyte characters. It is provided by the Gnulib module ‘mbchar’.
uc_is_lower
This function operates in a locale independent way, on Unicode characters. It is provided by the Gnulib module ‘unictype/ctype-lower’.
islower_l
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/islower_l.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
isnan
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/isnan.html
Gnulib module: isnan
Portability problems fixed by Gnulib:
isnan
was introduced with C99 and is thus commonly not present
on pre-C99 systems.
isnan
is not a macro on some platforms:
IRIX 6.5, Solaris 11.4.
cc
, isnan
does not recognize some NaNs.
Portability problems not fixed by Gnulib:
isnormal
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/isnormal.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
isprint
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/isprint.html
Gnulib module: ctype
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
Note: This function’s behaviour depends on the locale, but does not support
the multibyte characters that occur in strings in locales with
MB_CUR_MAX > 1
(this includes all the common UTF-8 locales).
There are five alternative APIs:
c_isprint
This function operates in a locale independent way and returns true only for ASCII characters. It is provided by the Gnulib module ‘c-ctype’.
iswprint
This function operates in a locale dependent way, on wide characters. In
order to use it, you first have to convert from multibyte to wide characters,
using the mbrtowc
function. It is provided by the Gnulib module
‘wctype’.
c32isprint
This function operates in a locale dependent way, on 32-bit wide characters.
In order to use it, you first have to convert from multibyte to 32-bit wide
characters, using the mbrtoc32
function. It is provided by the
Gnulib module ‘c32isprint’.
mb_isprint
This function operates in a locale dependent way, on multibyte characters. It is provided by the Gnulib module ‘mbchar’.
uc_is_print
This function operates in a locale independent way, on Unicode characters. It is provided by the Gnulib module ‘unictype/ctype-print’.
isprint_l
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/isprint_l.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
ispunct
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ispunct.html
Gnulib module: ctype
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
Note: This function’s behaviour depends on the locale, but does not support
the multibyte characters that occur in strings in locales with
MB_CUR_MAX > 1
(this includes all the common UTF-8 locales).
There are five alternative APIs:
c_ispunct
This function operates in a locale independent way and returns true only for ASCII characters. It is provided by the Gnulib module ‘c-ctype’.
iswpunct
This function operates in a locale dependent way, on wide characters. In
order to use it, you first have to convert from multibyte to wide characters,
using the mbrtowc
function. It is provided by the Gnulib module
‘wctype’.
c32ispunct
This function operates in a locale dependent way, on 32-bit wide characters.
In order to use it, you first have to convert from multibyte to 32-bit wide
characters, using the mbrtoc32
function. It is provided by the
Gnulib module ‘c32ispunct’.
mb_ispunct
This function operates in a locale dependent way, on multibyte characters. It is provided by the Gnulib module ‘mbchar’.
uc_is_punct
This function operates in a locale independent way, on Unicode characters. It is provided by the Gnulib module ‘unictype/ctype-punct’.
ispunct_l
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ispunct_l.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
isspace
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/isspace.html
Gnulib module: ctype
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
Note: This function’s behaviour depends on the locale, but does not support
the multibyte characters that occur in strings in locales with
MB_CUR_MAX > 1
(this includes all the common UTF-8 locales).
There are five alternative APIs:
c_isspace
This function operates in a locale independent way and returns true only for ASCII characters. It is provided by the Gnulib module ‘c-ctype’.
iswspace
This function operates in a locale dependent way, on wide characters. In
order to use it, you first have to convert from multibyte to wide characters,
using the mbrtowc
function. It is provided by the Gnulib module
‘wctype’.
c32isspace
This function operates in a locale dependent way, on 32-bit wide characters.
In order to use it, you first have to convert from multibyte to 32-bit wide
characters, using the mbrtoc32
function. It is provided by the
Gnulib module ‘c32isspace’.
mb_isspace
This function operates in a locale dependent way, on multibyte characters. It is provided by the Gnulib module ‘mbchar’.
uc_is_space
This function operates in a locale independent way, on Unicode characters. It is provided by the Gnulib module ‘unictype/ctype-space’.
isspace_l
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/isspace_l.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
isunordered
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/isunordered.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
isupper
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/isupper.html
Gnulib module: ctype
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
Note: This function’s behaviour depends on the locale, but does not support
the multibyte characters that occur in strings in locales with
MB_CUR_MAX > 1
(this includes all the common UTF-8 locales).
There are five alternative APIs:
c_isupper
This function operates in a locale independent way and returns true only for ASCII characters. It is provided by the Gnulib module ‘c-ctype’.
iswupper
This function operates in a locale dependent way, on wide characters. In
order to use it, you first have to convert from multibyte to wide characters,
using the mbrtowc
function. It is provided by the Gnulib module
‘wctype’.
c32isupper
This function operates in a locale dependent way, on 32-bit wide characters.
In order to use it, you first have to convert from multibyte to 32-bit wide
characters, using the mbrtoc32
function. It is provided by the
Gnulib module ‘c32isupper’.
mb_isupper
This function operates in a locale dependent way, on multibyte characters. It is provided by the Gnulib module ‘mbchar’.
uc_is_upper
This function operates in a locale independent way, on Unicode characters. It is provided by the Gnulib module ‘unictype/ctype-upper’.
isupper_l
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/isupper_l.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
iswalnum
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/iswalnum.html
Gnulib module: wctype-h
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and
therefore cannot accommodate all Unicode characters.
However, the Gnulib function c32isalnum
, provided by Gnulib module
c32isalnum
, operates on 32-bit wide characters and therefore does not
have this limitation.
iswalnum_l
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/iswalnum_l.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
iswalpha
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/iswalpha.html
Gnulib module: wctype-h
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and
therefore cannot accommodate all Unicode characters.
However, the Gnulib function c32isalpha
, provided by Gnulib module
c32isalpha
, operates on 32-bit wide characters and therefore does not
have this limitation.
iswalpha_l
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/iswalpha_l.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
iswblank
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/iswblank.html
Gnulib module: iswblank
Portability problems fixed by Gnulib:
-D_GNU_SOURCE
) on some platforms:
glibc 2.8.
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and
therefore cannot accommodate all Unicode characters.
However, the Gnulib function c32isblank
, provided by Gnulib module
c32isblank
, operates on 32-bit wide characters and therefore does not
have this limitation.
iswblank_l
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/iswblank_l.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
iswcntrl
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/iswcntrl.html
Gnulib module: wctype-h
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and
therefore cannot accommodate all Unicode characters.
However, the Gnulib function c32iscntrl
, provided by Gnulib module
c32iscntrl
, operates on 32-bit wide characters and therefore does not
have this limitation.
iswcntrl_l
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/iswcntrl_l.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
iswctype
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/iswctype.html
Gnulib module: iswctype
Portability problems fixed by Gnulib:
<wchar.h>
, not in <wctype.h>
, on
some platforms:
HP-UX 11.00.
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
However, the Gnulib function c32_apply_type_test
, provided by Gnulib
module c32_apply_type_test
, operates on 32-bit wide characters and
therefore does not have this limitation.
iswctype_l
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/iswctype_l.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
iswdigit
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/iswdigit.html
Gnulib module: iswdigit
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and
therefore cannot accommodate all Unicode characters.
However, the Gnulib function c32isdigit
, provided by Gnulib module
c32isdigit
, operates on 32-bit wide characters and therefore does not
have this limitation.
iswdigit_l
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/iswdigit_l.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
iswgraph
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/iswgraph.html
Gnulib module: wctype-h
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and
therefore cannot accommodate all Unicode characters.
However, the Gnulib function c32isgraph
, provided by Gnulib module
c32isgraph
, operates on 32-bit wide characters and therefore does not
have this limitation.
iswgraph_l
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/iswgraph_l.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
iswlower
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/iswlower.html
Gnulib module: wctype-h
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and
therefore cannot accommodate all Unicode characters.
However, the Gnulib function c32islower
, provided by Gnulib module
c32islower
, operates on 32-bit wide characters and therefore does not
have this limitation.
iswlower_l
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/iswlower_l.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
iswprint
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/iswprint.html
Gnulib module: wctype-h
Portability problems fixed by Gnulib:
'\t'
) character
on some platforms:
mingw.
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and
therefore cannot accommodate all Unicode characters.
However, the Gnulib function c32isprint
, provided by Gnulib module
c32isprint
, operates on 32-bit wide characters and therefore does not
have this limitation.
iswprint_l
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/iswprint_l.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
iswpunct
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/iswpunct.html
Gnulib module: iswpunct
Portability problems fixed by Gnulib:
ispunct
function, because it
returns false for the characters '$'
, '+'
, '<'
,
'='
, '>'
, '^'
, '`'
, '|'
, '~'
on some platforms:
Android 11.
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and
therefore cannot accommodate all Unicode characters.
However, the Gnulib function c32ispunct
, provided by Gnulib module
c32ispunct
, operates on 32-bit wide characters and therefore does not
have this limitation.
iswpunct_l
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/iswpunct_l.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
iswspace
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/iswspace.html
Gnulib module: wctype-h
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and
therefore cannot accommodate all Unicode characters.
However, the Gnulib function c32isspace
, provided by Gnulib module
c32isspace
, operates on 32-bit wide characters and therefore does not
have this limitation.
iswspace_l
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/iswspace_l.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
iswupper
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/iswupper.html
Gnulib module: wctype-h
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and
therefore cannot accommodate all Unicode characters.
However, the Gnulib function c32isupper
, provided by Gnulib module
c32isupper
, operates on 32-bit wide characters and therefore does not
have this limitation.
iswupper_l
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/iswupper_l.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
iswxdigit
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/iswxdigit.html
Gnulib module: iswxdigit
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and
therefore cannot accommodate all Unicode characters.
However, the Gnulib function c32isxdigit
, provided by Gnulib module
c32isxdigit
, operates on 32-bit wide characters and therefore does not
have this limitation.
iswxdigit_l
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/iswxdigit_l.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
isxdigit
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/isxdigit.html
Gnulib module: ctype
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
Note: This function’s behaviour depends on the locale, but does not support
the multibyte characters that occur in strings in locales with
MB_CUR_MAX > 1
(this includes all the common UTF-8 locales).
There are five alternative APIs:
c_isxdigit
This function operates in a locale independent way and returns true only for ASCII characters. It is provided by the Gnulib module ‘c-ctype’.
iswxdigit
This function operates in a locale dependent way, on wide characters. In
order to use it, you first have to convert from multibyte to wide characters,
using the mbrtowc
function. It is provided by the Gnulib module
‘wctype’.
c32isxdigit
This function operates in a locale dependent way, on 32-bit wide characters.
In order to use it, you first have to convert from multibyte to 32-bit wide
characters, using the mbrtoc32
function. It is provided by the
Gnulib module ‘c32isxdigit’.
mb_isxdigit
This function operates in a locale dependent way, on multibyte characters. It is provided by the Gnulib module ‘mbchar’.
uc_is_xdigit
This function operates in a locale independent way, on Unicode characters. It is provided by the Gnulib module ‘unictype/ctype-xdigit’.
isxdigit_l
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/isxdigit_l.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
j0
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/j0.html
Gnulib module: j0
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
j1
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/j1.html
Gnulib module: j1
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
jn
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/jn.html
Gnulib module: jn
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
jrand48
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/jrand48.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
kill
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/kill.html
LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-kill-3.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
killpg
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/killpg.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
l64a
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/l64a.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
labs
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/labs.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
lchown
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/lchown.html
Gnulib module: lchown
Portability problems fixed by Gnulib:
ENOSYS
:
mingw, MSVC 14.
lchown("link-to-file/",uid,gid)
:
FreeBSD 7.2, Solaris 9.
lchmod
, the replacement only fixes this for non-symlinks:
OpenBSD 4.0.
Portability problems not fixed by Gnulib:
EACCES
when the failure is
due to lack of appropriate privileges (EPERM
), not to
search permission denied on the file name prefix (EACCES
):
Linux kernel 5.15 with glibc 2.35 and a CIFS v1 file system
(see https://bugs.gnu.org/65599).
lcong48
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/lcong48.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
ldexp
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ldexp.html
Gnulib module: ldexp
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
ldexpf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ldexpf.html
Gnulib module: ldexpf
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
ldexpl
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ldexpl.html
Gnulib module: ldexpl
Portability problems fixed by Gnulib:
<math.h>
on some platforms:
Mac OS X.
Portability problems not fixed by Gnulib:
ldiv
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ldiv.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
lfind
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/lfind.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
lgamma
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/lgamma.html
Gnulib module: lgamma
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
lgammaf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/lgammaf.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
lgammal
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/lgammal.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
link
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/link.html
LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-link-1.html
Gnulib module: link
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
linkat
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/linkat.html
Gnulib module: linkat
Portability problems fixed by Gnulib:
AT_SYMLINK_FOLLOW
on some platforms:
Linux kernel 2.6.17.
Portability problems not fixed by Gnulib:
lio_listio
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/lio_listio.html
Gnulib module: —
Portability problems fixed by Gnulib:
off_t
is a 32-bit type, this function may not
work correctly on files 2 GiB and larger. See Large File Support.
Portability problems not fixed by Gnulib:
listen
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/listen.html
Gnulib module: listen
Portability problems fixed by Gnulib:
errno
, and WSAGetLastError
must be used
instead.
Portability problems not fixed by Gnulib:
llabs
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/llabs.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
lldiv
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/lldiv.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
llogb
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/Exponents-and-Logarithms.html.
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
llogbf
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/Exponents-and-Logarithms.html.
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
llogbl
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/Exponents-and-Logarithms.html.
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
llrint
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/llrint.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
llrintf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/llrintf.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
llrintl
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/llrintl.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
llround
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/llround.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
llroundf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/llroundf.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
llroundl
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/llroundl.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
localeconv
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/localeconv.html
Gnulib module: localeconv
Portability problems fixed by Gnulib:
struct lconv
type does not contain any members on some platforms:
Android up to 2014.
struct lconv
type does not contain the members
int_p_cs_precedes
, int_p_sign_posn
, int_p_sep_by_space
,
int_n_cs_precedes
, int_n_sign_posn
, int_n_sep_by_space
on some platforms:
glibc, OpenBSD 4.9, HP-UX 11, IRIX 6.5, Solaris 11.4, Cygwin 1.5.x, mingw, MSVC 14.
struct lconv
of type char
are -1 instead
of CHAR_MAX on some platforms:
mingw.
Portability problems not fixed by Gnulib:
localtime
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/localtime.html
Gnulib module: localtime
Portability problems fixed by Gnulib:
TZ
has been set by Cygwin.
Portability problems not fixed by Gnulib:
time_rz
module to work around the problem.
tzset
.
localtime_r
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/localtime_r.html
Gnulib module: time_r
Portability problems fixed by Gnulib:
_REENTRANT
is defined,
on some platforms:
HP-UX 11.
Portability problems not fixed by Gnulib:
time_rz
module to work around the problem.
lockf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/lockf.html
Gnulib module: —
Portability problems fixed by Gnulib:
off_t
is a 32-bit type, this function may not
work correctly across the entire data range of files 2 GiB and larger.
See Large File Support.
Portability problems not fixed by Gnulib:
log
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/log.html
Gnulib module: log or log-ieee
Portability problems fixed by either Gnulib module log
or log-ieee
:
Portability problems fixed by Gnulib module log-ieee
:
Portability problems not fixed by Gnulib:
log10
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/log10.html
Gnulib module: log10 or log10-ieee
Portability problems fixed by either Gnulib module log10
or log10-ieee
:
Portability problems fixed by Gnulib module log10-ieee
:
Portability problems not fixed by Gnulib:
log10f
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/log10f.html
Gnulib module: log10f or log10f-ieee
Portability problems fixed by either Gnulib module log10f
or log10f-ieee
:
Portability problems fixed by Gnulib module log10f-ieee
:
Portability problems not fixed by Gnulib:
log10l
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/log10l.html
Gnulib module: log10l
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
log1p
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/log1p.html
Gnulib module: log1p or log1p-ieee
Portability problems fixed by either Gnulib module log1p
or log1p-ieee
:
Portability problems fixed by Gnulib module log1p-ieee
:
Portability problems not fixed by Gnulib:
log1pf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/log1pf.html
Gnulib module: log1pf or log1pf-ieee
Portability problems fixed by either Gnulib module log1pf
or log1pf-ieee
:
-1.0f
on some platforms:
IRIX 6.5.
Portability problems fixed by Gnulib module log1pf-ieee
:
Portability problems not fixed by Gnulib:
log1pl
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/log1pl.html
Gnulib module: log1pl or log1pl-ieee
Portability problems fixed by either Gnulib module log1pl
or log1pl-ieee
:
Portability problems fixed by Gnulib module log1pl-ieee
:
Portability problems not fixed by Gnulib:
log2
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/log2.html
Gnulib module: log2 or log2-ieee
Portability problems fixed by either Gnulib module log2
or log2-ieee
:
Portability problems fixed by Gnulib module log2-ieee
:
Portability problems not fixed by Gnulib:
log2f
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/log2f.html
Gnulib module: log2f or log2f-ieee
Portability problems fixed by either Gnulib module log2f
or log2f-ieee
:
Portability problems fixed by Gnulib module log2f-ieee
:
Portability problems not fixed by Gnulib:
log2l
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/log2l.html
Gnulib module: log2l
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
logb
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/logb.html
Gnulib module: logb
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
logbf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/logbf.html
Gnulib module: logbf
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
logbl
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/logbl.html
Gnulib module: logbl
Portability problems fixed by Gnulib:
1.6810515715560467531313389086608763012990396724232e-4932L
on some platforms:
OpenBSD 7.3/mips64.
Portability problems not fixed by Gnulib:
logf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/logf.html
Gnulib module: logf or logf-ieee
Portability problems fixed by either Gnulib module logf
or logf-ieee
:
Portability problems fixed by Gnulib module logf-ieee
:
Portability problems not fixed by Gnulib:
logl
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/logl.html
Gnulib module: logl
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
longjmp
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/longjmp.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
sigaltstack
), on FreeBSD, NetBSD,
OpenBSD, you need to clear the SS_ONSTACK
flag in the stack_t
structure managed by the kernel.
lrand48
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/lrand48.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
lrint
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/lrint.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
lrintf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/lrintf.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
lrintl
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/lrintl.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
lround
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/lround.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
lroundf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/lroundf.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
lroundl
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/lroundl.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
lsearch
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/lsearch.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
lseek
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/lseek.html
Gnulib module: lseek
Portability problems fixed by Gnulib:
lseek (fd, offset, SEEK_DATA)
returns a value
greater than offset
even when offset
addresses data:
macOS 12
<io.h>
)
on some platforms:
MSVC 14.
off_t
is a 32-bit type, lseek
does not work
correctly with files 2 GiB and larger. See Large File Support.
Portability problems not fixed by Gnulib:
lseek
should set
errno
to EINVAL
and return −1, but in this situation a
SIGSYS
signal is raised on some platforms:
IRIX 6.5.
SEEK_DATA
and SEEK_HOLE
:
AIX, HP-UX, Microsoft Windows, NetBSD, OpenBSD.
SEEK_DATA
and SEEK_HOLE
,
and Gnulib works around the problem via #undef SEEK_DATA
and #undef SEEK_HOLE
:
FreeBSD 13, macOS 12.
lstat
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/lstat.html
Gnulib module: lstat
Portability problems fixed by Gnulib:
off_t
is a 32-bit type, lstat
may not
correctly report the size of files or block devices 2 GiB and larger.
See Large File Support.
lstat("file/",buf)
succeeds instead of
failing with ENOTDIR
.
macOS 11.1, Solaris 9.
tv_sec
value, tv_nsec
might be in the range
−1000000000..−1, representing a negative nanoseconds
offset from tv_sec
.
lstat
does not exist.
Portability problems not fixed by Gnulib:
struct stat
.
malloc
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/malloc.html
Gnulib module: malloc-posix
Portability problems fixed by Gnulib:
errno
to ENOMEM
on
some platforms:
mingw, MSVC 14.
malloc (n)
can succeed even if n
exceeds PTRDIFF_MAX
. Although this behavior is arguably
allowed by POSIX it can lead to behavior not defined by POSIX later,
so malloc-posix
does not allow going over the limit.
Extension: Gnulib provides a module ‘malloc-gnu’ that substitutes a
malloc
implementation that behaves more like the glibc implementation,
by fixing this portability problem:
malloc (0)
returns NULL
on success on some platforms:
AIX 7.2.
mblen
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/mblen.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
mbrlen
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/mbrlen.html
Gnulib module: mbrlen
Portability problems fixed by Gnulib:
(size_t) -1
and set errno
to EILSEQ
:
glibc 2.35.
(size_t) -2
when the input
is empty:
glibc 2.19.
(size_t) -1
instead of (size_t) -2
when the input is empty:
AIX 5.1.
Portability problems not fixed by Gnulib:
mbrtoc8
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
mbrtoc16
¶Gnulib module: mbrtoc16
Portability problems fixed by Gnulib:
(size_t) -1
and set errno
to EILSEQ
:
glibc 2.36.
(size_t) -2
when the input
is empty:
glibc 2.19,
Android 11.
(size_t) -3
instead of a byte count when it
has stored a high surrogate, and returns a byte count instead of
(size_t) -3
when it has stored a low surrogate, on some platforms:
Android.
mbrtowc
recognizes on some platforms:
FreeBSD 13.2,
Solaris 11.4, MSVC 14.
Portability problems not fixed by Gnulib:
mbrtoc16
returns a char16_t
value, mbsinit
cannot be used to determine whether the function is ready to return
another char16_t
value. To do so, instead call mbrtoc16
again, with an appropriately incremented const char *
argument
and an appropriately decremented size_t
argument.
mbrtoc32
¶Gnulib module: mbrtoc32 or mbrtoc32-regular
Portability problems fixed by either Gnulib module mbrtoc32
or mbrtoc32-regular
:
(size_t) -1
and set errno
to EILSEQ
:
glibc 2.35.
(size_t) -2
when the input
is empty:
glibc 2.19,
mingw,
Android 11,
Haiku.
mbrtowc
recognizes on some platforms:
FreeBSD 13.2,
Solaris 11.4, mingw, MSVC 14.
Portability problems fixed by Gnulib module mbrtoc32-regular
:
(size_t) -3
.
No known implementation currently (2023) behaves that way, but it may
theoretically happen.
With the mbrtoc32-regular
module, you have the guarantee that the
Gnulib-provided mbrtoc32
function maps each multibyte character to
exactly one Unicode character and thus never returns (size_t) -3
.
Portability problems not fixed by Gnulib:
Note: If you want the guarantee that the char32_t
values returned
by this function are Unicode code points, you also need to request the
uchar-c23
module.
mbrtowc
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/mbrtowc.html
Gnulib module: mbrtowc
Portability problems fixed by Gnulib:
(size_t) -1
and set errno
to EILSEQ
:
glibc 2.35.
(size_t) -2
when the input
is empty:
glibc 2.19,
MSVC 14, Android 11.
(size_t) -1
instead of (size_t) -2
when the input is empty:
AIX 7.2.
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and
therefore cannot accommodate all Unicode characters.
However, the ISO C11 function mbrtoc32
, provided by Gnulib module
mbrtoc32
, operates on 32-bit wide characters and therefore does not have
this limitation.
mbsinit
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/mbsinit.html
Gnulib module: mbsinit
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
mbrtoc16
or mbrtoc8
.
mbsnrtowcs
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/mbsnrtowcs.html
Gnulib module: mbsnrtowcs
Portability problems fixed by Gnulib:
(size_t) -1
and set errno
to EILSEQ
:
glibc 2.35.
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and
therefore cannot accommodate all Unicode characters.
However, the Gnulib function mbsnrtoc32s
, provided by Gnulib module
mbsnrtoc32s
, operates on 32-bit wide characters and therefore does not
have this limitation.
mbsrtowcs
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/mbsrtowcs.html
Gnulib module: mbsrtowcs
Portability problems fixed by Gnulib:
(size_t) -1
and set errno
to EILSEQ
:
glibc 2.35.
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and
therefore cannot accommodate all Unicode characters.
However, the Gnulib function mbsrtoc32s
, provided by Gnulib module
mbsrtoc32s
, operates on 32-bit wide characters and therefore does not
have this limitation.
mbstowcs
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/mbstowcs.html
Gnulib module: mbstowcs
Portability problems fixed by Gnulib:
(size_t) -1
and set errno
to EILSEQ
:
glibc 2.35.
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and
therefore cannot accommodate all Unicode characters.
However, the Gnulib function mbstoc32s
, provided by Gnulib module
mbstoc32s
, operates on 32-bit wide characters and therefore does not
have this limitation.
mbtowc
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/mbtowc.html
Gnulib module: mbtowc
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
memccpy
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/memccpy.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
memchr
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/memchr.html
Gnulib module: memchr
Portability problems fixed by Gnulib:
unsigned char
on some platforms:
Android 5.0.
Portability problems not fixed by Gnulib:
memcmp
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/memcmp.html
Gnulib module: memcmp
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
memcpy
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/memcpy.html
Gnulib module: memcpy
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
memmove
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/memmove.html
Gnulib module: memmove
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
memset
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/memset.html
Gnulib module: memset
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
memset_explicit
¶Documentation:
Gnulib module: memset_explicit
The memset_explicit
function is an approximation to what is
needed, and does not suffice in general to erase information.
Although calling memset_explicit
should clear the memory in
question, the information that was in memory may still be available
elsewhere on the machine. Proper implementation of information
erasure requires support from levels below C code.
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
mkdir
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/mkdir.html
Gnulib module: sys_stat or mkdir
Portability problems fixed by either Gnulib module sys_stat
or mkdir
:
<io.h>
or
<direct.h>
) on some platforms:
mingw, MSVC 14.
_mkdir
and takes only one argument. The fix (without Gnulib) is to define a macro
like this:
#define mkdir ((int (*)()) _mkdir)
or
#define mkdir(path,mode) _mkdir (path)
Portability problems fixed by Gnulib module mkdir
:
Portability problems not fixed by Gnulib:
mkdirat
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/mkdirat.html
Gnulib module: mkdirat
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
mkdtemp
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/mkdtemp.html
Gnulib module: mkdtemp
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
mkfifo
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/mkfifo.html
Gnulib module: mkfifo
Portability problems fixed by Gnulib:
ENOSYS
:
mingw, MSVC 14, Android 4.4.
Portability problems not fixed by Gnulib:
EISDIR
instead of the correct EEXIST
:
HP-UX 11.11.
mkfifoat
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/mkfifoat.html
Gnulib module: mkfifoat
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
EISDIR
instead of the correct
EEXIST
: HP-UX 11.11.
mknod
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/mknod.html
Gnulib module: mknod
Portability problems fixed by Gnulib:
ENOSYS
:
mingw, MSVC 14.
Portability problems not fixed by Gnulib:
EISDIR
instead of the correct EEXIST
:
HP-UX 11.11.
mknodat
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/mknodat.html
Gnulib module: mkfifoat
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
EISDIR
instead of the correct
EEXIST
: HP-UX 11.11.
mkstemp
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/mkstemp.html
Gnulib module: mkstemp
Portability problems fixed by Gnulib:
off_t
is a 32-bit type, mkstemp
may not work
correctly to create files 2 GiB and larger. See Large File Support.
mkstemp
can create a world or group
writable or readable file, if you haven’t set the process umask to
077. This is a security risk.
Portability problems not fixed by Gnulib:
The gnulib module clean-temp
can create temporary files that will not
be left behind after signals such as SIGINT.
mktime
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/mktime.html
Gnulib module: mktime
Portability problems fixed by Gnulib:
TZ
has been set by Cygwin.
mktime
may go into an endless loop on some platforms.
mktime
may occasionally return wrong results on some platforms.
Portability problems not fixed by Gnulib:
tzset
.
mlock
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/mlock.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
mlockall
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/mlockall.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
mmap
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/mmap.html
Gnulib module: —
Portability problems fixed by Gnulib:
off_t
is a 32-bit type, this function may not
work correctly across the entire data range of files 2 GiB and larger.
See Large File Support.
Portability problems not fixed by Gnulib:
MAP_ANONYMOUS | MAP_PRIVATE
and -1
instead of a file descriptor;
on others you have to use a read-only file descriptor of /dev/zero.
MAP_FIXED
), often causes mmap
to fail. Better pass NULL
in this case.
MAP_FIXED
basically never works. On other platforms, it depends
on the circumstances whether memory can be returned at a given address.
modf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/modf.html
Gnulib module: modf or modf-ieee
Portability problems fixed by either Gnulib module modf
or modf-ieee
:
Portability problems fixed by Gnulib module modf-ieee
:
Portability problems not fixed by Gnulib:
modff
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/modff.html
Gnulib module: modff or modff-ieee
Portability problems fixed by either Gnulib module modff
or modff-ieee
:
Portability problems fixed by Gnulib module modff-ieee
:
Portability problems not fixed by Gnulib:
modfl
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/modfl.html
Gnulib module: modfl or modfl-ieee
Portability problems fixed by either Gnulib module modfl
or modfl-ieee
:
Portability problems fixed by Gnulib module modfl-ieee
:
Portability problems not fixed by Gnulib:
mprotect
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/mprotect.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
errno
on some platforms:
mingw.
mprotect
on memory regions allocated
with malloc
.
mq_close
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/mq_close.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
mq_getattr
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/mq_getattr.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
mq_notify
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/mq_notify.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
mq_open
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/mq_open.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
mq_receive
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/mq_receive.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
mq_send
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/mq_send.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
mq_setattr
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/mq_setattr.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
mq_timedreceive
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/mq_timedreceive.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
mq_timedsend
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/mq_timedsend.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
mq_unlink
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/mq_unlink.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
mrand48
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/mrand48.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
msgctl
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/msgctl.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
msgget
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/msgget.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
msgrcv
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/msgrcv.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
msgsnd
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/msgsnd.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
msync
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/msync.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
msync
takes only two arguments.
mtx_destroy
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/ISO-C-Mutexes.html.
Gnulib module: mtx
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
mtx_init
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/ISO-C-Mutexes.html.
Gnulib module: mtx
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
mtx_lock
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/ISO-C-Mutexes.html.
Gnulib module: mtx
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
mtx_timedlock
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/ISO-C-Mutexes.html.
Gnulib module: mtx
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
mtx_trylock
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/ISO-C-Mutexes.html.
Gnulib module: mtx
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
mtx_unlock
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/ISO-C-Mutexes.html.
Gnulib module: mtx
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
munlock
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/munlock.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
munlockall
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/munlockall.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
munmap
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/munmap.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
nan
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/nan.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
nanf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/nanf.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
nanl
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/nanl.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
nanosleep
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/nanosleep.html
Gnulib module: nanosleep
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
nearbyint
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/nearbyint.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
nearbyintf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/nearbyintf.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
nearbyintl
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/nearbyintl.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
newlocale
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/newlocale.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
locale_t
type is not defined
on some platforms:
z/OS.
locale_t
type contains basically
no information on some platforms:
OpenBSD 6.3.
nextafter
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/nextafter.html
Gnulib module: nextafter
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
nextafterf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/nextafterf.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
nextafterl
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/nextafterl.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
nextdown
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
nextdownf
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
nextdownl
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
nexttoward
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/nexttoward.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
nexttowardf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/nexttowardf.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
nexttowardl
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/nexttowardl.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
nextup
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
nextupf
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
nextupl
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
nftw
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/nftw.html
Gnulib module: —
Portability problems fixed by Gnulib:
off_t
is a 32-bit type, this function may not
correctly report the size of files or block devices 2 GiB and larger.
See Large File Support.
Portability problems not fixed by Gnulib:
nice
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/nice.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
nice
returned 0 upon success.
nl_langinfo
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/nl_langinfo.html
Gnulib module: nl_langinfo
Portability problems fixed by Gnulib:
CODESET
is not supported on some platforms:
OpenBSD 3.8.
ALTMON_1
to ALTMON_12
are not defined on some
platforms:
glibc 2.26, musl libc, macOS 11.1, NetBSD 8.0, OpenBSD 6.7, AIX 7.2, HP-UX 11.31, IRIX 6.5, Solaris 11.4, Haiku, Cygwin 2.9.
ERA
, ERA_D_FMT
, ERA_D_T_FMT
,
ERA_T_FMT
, ALT_DIGITS
are not supported on some platforms:
OpenBSD 6.7.
YESEXPR
and NOEXPR
do not return a valid
string on some platforms:
IRIX 6.5.
Portability problems not fixed by Gnulib:
nl_langinfo(CODESET)
always
returns "US-ASCII"
.
nl_langinfo(CRNCYSTR)
returns the
empty string, although the local currency symbol, as returned by
localeconv()->currency_symbol
, is non-empty.
nl_langinfo(ABMON_1)
... nl_langinfo(ABMON_12)
are full month
names, not abbreviated month names.
nl_langinfo_l
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/nl_langinfo_l.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
nrand48
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/nrand48.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
ntohl
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ntohl.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
ntohs
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ntohs.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
open
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/open.html
Gnulib module: open, fchdir
Portability problems fixed by the Gnulib module open
:
O_CLOEXEC
:
Mac OS X 10.6, FreeBSD 8.4, NetBSD 5.1, OpenBSD 4.9, Minix 3.1.8, AIX 7.1, HP-UX 11, IRIX 6.5, Solaris 10, Cygwin 1.7.x, mingw, MSVC 14.
off_t
is a 32-bit type, open
may not work
correctly with files 2 GiB and larger. See Large File Support.
O_NONBLOCK
flag when it is defined
by the gnulib module nonblocking
on some platforms:
mingw, MSVC 14.
Portability problems fixed by the Gnulib module fchdir
:
Portability problems not fixed by Gnulib:
O_CLOEXEC
is not atomic, and so is
not safe in the presence of multiple threads or signal handlers.
open ("symlink", O_CREAT ...)
fails when the argument points to a
nonexistent file in an existing directory on some platforms:
Haiku.
open ("symlink", O_NOFOLLOW ...)
fails with errno
set to
EMLINK
instead of the POSIX-required ELOOP
on some
platforms:
FreeBSD 10.1.
open ("symlink", O_NOFOLLOW ...)
fails with errno
set to
EFTYPE
instead of the POSIX-required ELOOP
on some
platforms:
NetBSD 6.1.
O_TEXT
mode by
default; this means that it translates '\n'
to CR/LF by default. Use the
O_BINARY
flag if you need reliable binary I/O.
openat
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/openat.html
Gnulib module: openat
Portability problems fixed by Gnulib:
O_CLOEXEC
:
AIX 7.1, Solaris 10.
off_t
is a 32-bit type, open
may not work
correctly with files 2 GiB and larger. See Large File Support.
Portability problems not fixed by Gnulib:
O_CLOEXEC
is not atomic, and so is
not safe in the presence of multiple threads or signal handlers.
openat (fd, "symlink", O_NOFOLLOW ...)
fails with errno
set to EMLINK
instead of the POSIX-required ELOOP
on
some platforms:
FreeBSD 10.1.
openat (fd, "symlink", O_NOFOLLOW ...)
fails with errno
set to EFTYPE
instead of the POSIX-required ELOOP
on
some platforms:
NetBSD 6.1.
opendir
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/opendir.html
Gnulib module: opendir
Portability problems fixed by Gnulib:
off_t
is a 32-bit type, this function may not
work correctly on huge directories 2 GiB and larger. Also, on platforms
where ino_t
is a 32-bit type, this function may report inode numbers
incorrectly. See Large File Support.
Portability problems not fixed by Gnulib:
openlog
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/openlog.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
open_memstream
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/open_memstream.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
An alternative to the open_memstream
function is the Gnulib module
string-buffer
.
open_wmemstream
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/open_wmemstream.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
optarg
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/optarg.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
opterr
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/opterr.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
optind
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/optind.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
optopt
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/optopt.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pathconf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pathconf.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pause
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pause.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pclose
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pclose.html
Gnulib module: pclose
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
perror
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/perror.html
Gnulib module: perror
Portability problems fixed by Gnulib:
errno
of 0 like failure, although POSIX
requires that the message declare it as a success, on some platforms:
FreeBSD 8.2, OpenBSD 4.7, macOS 11.1.
strerror
buffer on some platforms:
Cygwin 1.7.9, Android 11.
Portability problems not fixed by Gnulib:
ferror
) on write failure, but not all platforms do this:
glibc 2.13, cygwin 1.7.9.
pipe
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pipe.html
Gnulib module: pipe-posix
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
EMFILE
if no
resources are left on some platforms:
Cygwin 1.7.9.
poll
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/poll.html
Gnulib module: poll
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
poll
replacement might
return 0 even before the timeout has passed. Programs using it with pipes can
thus busy wait.
popen
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/popen.html
Gnulib module: popen
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
COMSPEC
is not set.
popen
calls into subsequent popen
children:
Cygwin 1.5.x.
posix_fadvise
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_fadvise.html
Gnulib module: —
Portability problems fixed by Gnulib:
off_t
is a 32-bit type, this function may not
work correctly across the entire data range of files 2 GiB and larger.
See Large File Support.
Portability problems not fixed by Gnulib:
posix_fallocate
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_fallocate.html
Gnulib module: —
Portability problems fixed by Gnulib:
off_t
is a 32-bit type, this function may not
work correctly across the entire data range of files 2 GiB and larger.
See Large File Support.
Portability problems not fixed by Gnulib:
posix_madvise
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_madvise.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
posix_mem_offset
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_mem_offset.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
posix_memalign
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_memalign.html
Gnulib module: posix_memalign
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
The Gnulib module aligned-malloc
provides functions for
allocating and freeing blocks of suitably aligned memory.
The Gnulib module pagealign_alloc
provides a similar API for
allocating and freeing blocks of memory aligned on a system page boundary.
posix_openpt
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_openpt.html
Gnulib module: posix_openpt
Portability problems fixed by Gnulib:
ENOSYS
or ENOENT
on
some platforms.
Portability problems not fixed by Gnulib:
Note that when using this function to open the master side of a
pseudo-terminal, you still need platform dependent code to open the
corresponding slave side. The Gnulib module openpty
provides
an easy-to-use API that does both at once.
posix_spawn
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_spawn.html
Gnulib module: posix_spawn
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
The Gnulib modules posix_spawn_file_actions_addchdir
and
posix_spawn_file_actions_addfchdir
provide additional actions,
that consist in changing the current directory of the child process
before starting the specified program.
posix_spawn_file_actions_addclose
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_spawn_file_actions_addclose.html
Gnulib module: posix_spawn_file_actions_addclose
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
posix_spawn_file_actions_adddup2
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_spawn_file_actions_adddup2.html
Gnulib module: posix_spawn_file_actions_adddup2
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
posix_spawn_file_actions_addopen
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_spawn_file_actions_addopen.html
Gnulib module: posix_spawn_file_actions_addopen
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
posix_spawn_file_actions_destroy
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_spawn_file_actions_destroy.html
Gnulib module: posix_spawn_file_actions_destroy
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
posix_spawn_file_actions_init
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_spawn_file_actions_init.html
Gnulib module: posix_spawn_file_actions_init
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
posix_spawnattr_destroy
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_spawnattr_destroy.html
Gnulib module: posix_spawnattr_destroy
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
posix_spawnattr_getflags
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_spawnattr_getflags.html
Gnulib module: posix_spawnattr_getflags
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
posix_spawnattr_getpgroup
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_spawnattr_getpgroup.html
Gnulib module: posix_spawnattr_getpgroup
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
posix_spawnattr_getschedparam
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_spawnattr_getschedparam.html
Gnulib module: posix_spawnattr_getschedparam
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
posix_spawnattr_getschedpolicy
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_spawnattr_getschedpolicy.html
Gnulib module: posix_spawnattr_getschedpolicy
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
posix_spawnattr_getsigdefault
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_spawnattr_getsigdefault.html
Gnulib module: posix_spawnattr_getsigdefault
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
posix_spawnattr_getsigmask
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_spawnattr_getsigmask.html
Gnulib module: posix_spawnattr_getsigmask
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
posix_spawnattr_init
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_spawnattr_init.html
Gnulib module: posix_spawnattr_init
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
posix_spawnattr_setflags
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_spawnattr_setflags.html
Gnulib module: posix_spawnattr_setflags
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
posix_spawnattr_setpgroup
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_spawnattr_setpgroup.html
Gnulib module: posix_spawnattr_setpgroup
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
posix_spawnattr_setschedparam
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_spawnattr_setschedparam.html
Gnulib module: posix_spawnattr_setschedparam
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
posix_spawnattr_setschedpolicy
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_spawnattr_setschedpolicy.html
Gnulib module: posix_spawnattr_setschedpolicy
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
posix_spawnattr_setsigdefault
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_spawnattr_setsigdefault.html
Gnulib module: posix_spawnattr_setsigdefault
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
posix_spawnattr_setsigmask
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_spawnattr_setsigmask.html
Gnulib module: posix_spawnattr_setsigmask
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
posix_spawnp
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_spawnp.html
Gnulib module: posix_spawnp
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
The Gnulib modules posix_spawn_file_actions_addchdir
and
posix_spawn_file_actions_addfchdir
provide additional actions,
that consist in changing the current directory of the child process
before starting the specified program.
posix_trace_attr_destroy
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_attr_destroy.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
posix_trace_attr_getclockres
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_attr_getclockres.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
posix_trace_attr_getcreatetime
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_attr_getcreatetime.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
posix_trace_attr_getgenversion
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_attr_getgenversion.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
posix_trace_attr_getinherited
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_attr_getinherited.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
posix_trace_attr_getlogfullpolicy
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_attr_getlogfullpolicy.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
posix_trace_attr_getlogsize
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_attr_getlogsize.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
posix_trace_attr_getmaxdatasize
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_attr_getmaxdatasize.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
posix_trace_attr_getmaxsystemeventsize
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_attr_getmaxsystemeventsize.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
posix_trace_attr_getmaxusereventsize
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_attr_getmaxusereventsize.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
posix_trace_attr_getname
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_attr_getname.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
posix_trace_attr_getstreamfullpolicy
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_attr_getstreamfullpolicy.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
posix_trace_attr_getstreamsize
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_attr_getstreamsize.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
posix_trace_attr_init
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_attr_init.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
posix_trace_attr_setinherited
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_attr_setinherited.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
posix_trace_attr_setlogfullpolicy
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_attr_setlogfullpolicy.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
posix_trace_attr_setlogsize
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_attr_setlogsize.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
posix_trace_attr_setmaxdatasize
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_attr_setmaxdatasize.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
posix_trace_attr_setname
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_attr_setname.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
posix_trace_attr_setstreamfullpolicy
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_attr_setstreamfullpolicy.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
posix_trace_attr_setstreamsize
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_attr_setstreamsize.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
posix_trace_clear
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_clear.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
posix_trace_close
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_close.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
posix_trace_create
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_create.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
posix_trace_create_withlog
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_create_withlog.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
posix_trace_event
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_event.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
posix_trace_eventid_equal
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_eventid_equal.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
posix_trace_eventid_get_name
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_eventid_get_name.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
posix_trace_eventid_open
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_eventid_open.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
posix_trace_eventset_add
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_eventset_add.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
posix_trace_eventset_del
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_eventset_del.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
posix_trace_eventset_empty
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_eventset_empty.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
posix_trace_eventset_fill
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_eventset_fill.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
posix_trace_eventset_ismember
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_eventset_ismember.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
posix_trace_eventtypelist_getnext_id
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_eventtypelist_getnext_id.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
posix_trace_eventtypelist_rewind
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_eventtypelist_rewind.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
posix_trace_flush
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_flush.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
posix_trace_get_attr
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_get_attr.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
posix_trace_get_filter
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_get_filter.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
posix_trace_get_status
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_get_status.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
posix_trace_getnext_event
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_getnext_event.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
posix_trace_open
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_open.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
posix_trace_rewind
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_rewind.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
posix_trace_set_filter
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_set_filter.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
posix_trace_shutdown
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_shutdown.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
posix_trace_start
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_start.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
posix_trace_stop
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_stop.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
posix_trace_timedgetnext_event
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_timedgetnext_event.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
posix_trace_trid_eventid_open
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_trid_eventid_open.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
posix_trace_trygetnext_event
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_trygetnext_event.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
posix_typed_mem_get_info
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_typed_mem_get_info.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
posix_typed_mem_open
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_typed_mem_open.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pow
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pow.html
Gnulib module: pow
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
powf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/powf.html
Gnulib module: powf
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
powl
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/powl.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pread
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pread.html
Gnulib module: pread
Portability problems fixed by Gnulib:
off_t
is a 32-bit type, this function may not
work correctly on files 2 GiB and larger. See Large File Support.
Portability problems not fixed by Gnulib:
printf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/printf.html
Gnulib module: printf-posix or printf-gnu or stdio, nonblocking, sigpipe
Portability problems fixed by either Gnulib module printf-posix
or printf-gnu
:
hh
, ll
,
j
, t
, z
) on some platforms:
AIX 5.1, HP-UX 11.23, IRIX 6.5, Solaris 9, Cygwin 1.5.24, old mingw, MSVC 9.
w8
,
w16
, w32
, w64
, wf8
, wf16
, wf32
,
wf64
) on some platforms:
glibc, musl libc, macOS 12.5, FreeBSD 13.1, NetBSD 9.0, OpenBSD 7.2,
AIX 7.2, HP-UX 11, IRIX 6.5, Solaris 11.4, Cygwin 2.9.0, mingw, MSVC 14.
"%f"
, "%e"
, "%g"
of Infinity and NaN yields an
incorrect result on some platforms:
AIX 5.2, Solaris 11.4, mingw, MSVC 14.
_FORTIFY_SOURCE >= 2
(set by default on Ubuntu),
Android, OpenBSD, macOS 11.1, MSVC 14.
"%2$s"
, on some platforms:
NetBSD 3.0, mingw, MSVC 14.
'
flag on some platforms:
NetBSD 3.0, Cygwin 1.5.24, mingw, MSVC 14.
"%010f"
of NaN and Infinity yields an incorrect result (padded
with zeroes, or wrong capitalization) on some platforms:
Mac OS X 10.5, FreeBSD 6.0, NetBSD 5.0, AIX 5.2, IRIX 6.5, Solaris 11.4, Cygwin 1.5.x, mingw, MSVC/clang.
"%#.0x"
or "%#.0X"
with a zero argument yields an
incorrect result (non-empty) on some platforms:
Mac OS X 10.6.
Portability problems fixed by Gnulib module printf-gnu
:
Portability problems fixed by Gnulib module stdio
or printf-posix
or printf-gnu
, together with module nonblocking
:
errno
being set to ENOSPC
instead of EAGAIN
on some
platforms:
mingw, MSVC 14.
Portability problems fixed by Gnulib module stdio
or printf-posix
or printf-gnu
, together with module sigpipe
:
SIGPIPE
handler, on some platforms:
mingw, MSVC 14.
Portability problems not fixed by Gnulib:
%m
directive is not portable, use %s
mapped to an
argument of strerror(errno)
(or a version of strerror_r
)
instead.
EOF
but
does not set the error flag for ferror
on some platforms:
glibc 2.13, cygwin 1.7.9.
pselect
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pselect.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
_ALL_SOURCE
is defined).
psiginfo
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/psiginfo.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
psignal
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/psignal.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_atfork
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_atfork.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_attr_destroy
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_attr_destroy.html
Gnulib module: pthread-thread
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_attr_getdetachstate
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_attr_getdetachstate.html
Gnulib module: pthread-thread
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_attr_getguardsize
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_attr_getguardsize.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_attr_getinheritsched
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_attr_getinheritsched.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_attr_getschedparam
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_attr_getschedparam.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_attr_getschedpolicy
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_attr_getschedpolicy.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_attr_getscope
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_attr_getscope.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_attr_getstack
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_attr_getstack.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_attr_getstacksize
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_attr_getstacksize.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_attr_init
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_attr_init.html
Gnulib module: pthread-thread
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_attr_setdetachstate
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_attr_setdetachstate.html
Gnulib module: pthread-thread
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_attr_setguardsize
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_attr_setguardsize.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_attr_setinheritsched
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_attr_setinheritsched.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_attr_setschedparam
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_attr_setschedparam.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_attr_setschedpolicy
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_attr_setschedpolicy.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_attr_setscope
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_attr_setscope.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_attr_setstack
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_attr_setstack.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_attr_setstacksize
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_attr_setstacksize.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_barrier_destroy
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_barrier_destroy.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_barrier_init
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_barrier_init.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_barrier_wait
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_barrier_wait.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_barrierattr_destroy
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_barrierattr_destroy.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_barrierattr_init
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_barrierattr_init.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_cancel
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_cancel.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_cleanup_pop
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_cleanup_pop.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_cleanup_push
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_cleanup_push.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_cond_broadcast
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_cond_broadcast.html
Gnulib module: pthread-cond
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_cond_destroy
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_cond_destroy.html
Gnulib module: pthread-cond
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_cond_init
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_cond_init.html
Gnulib module: pthread-cond
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_cond_signal
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_cond_signal.html
Gnulib module: pthread-cond
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_cond_timedwait
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_cond_timedwait.html
Gnulib module: pthread-cond
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_cond_wait
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_cond_wait.html
Gnulib module: pthread-cond
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_condattr_destroy
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_condattr_destroy.html
Gnulib module: pthread-cond
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_condattr_getclock
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_condattr_getclock.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_condattr_init
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_condattr_init.html
Gnulib module: pthread-cond
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_condattr_setclock
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_condattr_setclock.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_create
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_create.html
Gnulib module: pthread-thread
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_detach
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_detach.html
Gnulib module: pthread-thread
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_equal
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_equal.html
Gnulib module: pthread-thread
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_exit
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_exit.html
Gnulib module: pthread-thread
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_getconcurrency
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_getconcurrency.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_getcpuclockid
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_getcpuclockid.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_getschedparam
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_getschedparam.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_getspecific
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_getspecific.html
Gnulib module: pthread-tss
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_join
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_join.html
Gnulib module: pthread-thread
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_key_create
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_key_create.html
Gnulib module: pthread-tss
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_key_delete
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_key_delete.html
Gnulib module: pthread-tss
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_kill
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_kill.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_mutex_consistent
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_mutex_consistent.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_mutex_destroy
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_mutex_destroy.html
Gnulib module: pthread-mutex
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_mutex_getprioceiling
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_mutex_getprioceiling.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_mutex_init
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_mutex_init.html
Gnulib module: pthread-mutex
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_mutex_lock
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_mutex_lock.html
Gnulib module: pthread-mutex
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_mutex_setprioceiling
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_mutex_setprioceiling.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_mutex_timedlock
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_mutex_timedlock.html
Gnulib module: pthread_mutex_timedlock
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_mutex_trylock
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_mutex_trylock.html
Gnulib module: pthread-mutex
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_mutex_unlock
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_mutex_unlock.html
Gnulib module: pthread-mutex
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_mutexattr_destroy
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_mutexattr_destroy.html
Gnulib module: pthread-mutex
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_mutexattr_getprioceiling
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_mutexattr_getprioceiling.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_mutexattr_getprotocol
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_mutexattr_getprotocol.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_mutexattr_getrobust
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_mutexattr_getrobust.html
Gnulib module: pthread-mutex
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_mutexattr_gettype
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_mutexattr_gettype.html
Gnulib module: pthread-mutex
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_mutexattr_init
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_mutexattr_init.html
Gnulib module: pthread-mutex
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_mutexattr_setprioceiling
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_mutexattr_setprioceiling.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_mutexattr_setprotocol
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_mutexattr_setprotocol.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_mutexattr_setrobust
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_mutexattr_setrobust.html
Gnulib module: pthread-mutex
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_mutexattr_settype
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_mutexattr_settype.html
Gnulib module: pthread-mutex
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_once
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_once.html
Gnulib module: pthread-once
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_rwlock_destroy
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_rwlock_destroy.html
Gnulib module: pthread-rwlock
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_rwlock_init
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_rwlock_init.html
Gnulib module: pthread-rwlock
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_rwlock_rdlock
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_rwlock_rdlock.html
Gnulib module: pthread-rwlock
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
gl_rwlock_t
type from the Gnulib
module ‘lock’.
pthread_rwlock_timedrdlock
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_rwlock_timedrdlock.html
Gnulib module: pthread-rwlock
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_rwlock_timedwrlock
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_rwlock_timedwrlock.html
Gnulib module: pthread-rwlock
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_rwlock_tryrdlock
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_rwlock_tryrdlock.html
Gnulib module: pthread-rwlock
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_rwlock_trywrlock
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_rwlock_trywrlock.html
Gnulib module: pthread-rwlock
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_rwlock_unlock
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_rwlock_unlock.html
Gnulib module: pthread-rwlock
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_rwlock_wrlock
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_rwlock_wrlock.html
Gnulib module: pthread-rwlock
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_rwlockattr_destroy
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_rwlockattr_destroy.html
Gnulib module: pthread-rwlock
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_rwlockattr_init
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_rwlockattr_init.html
Gnulib module: pthread-rwlock
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_self
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_self.html
Gnulib module: pthread-thread
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_setcancelstate
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_setcancelstate.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_setcanceltype
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_setcanceltype.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_setconcurrency
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_setconcurrency.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_setschedparam
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_setschedparam.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_setschedprio
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_setschedprio.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_setspecific
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_setspecific.html
Gnulib module: pthread-tss
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_sigmask
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_sigmask.html
Gnulib module: pthread_sigmask
Portability problems fixed by Gnulib:
<pthread.h>
instead of <signal.h>
on some platforms:
FreeBSD 6.4, OpenBSD 3.8.
-lpthread
on some platforms:
FreeBSD 13.0, MidnightBSD 1.1, HP-UX 11.31, Solaris 9.
Portability problems not fixed by Gnulib:
pthread_spin_destroy
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_spin_destroy.html
Gnulib module: pthread-spin
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_spin_init
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_spin_init.html
Gnulib module: pthread-spin
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_spin_lock
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_spin_lock.html
Gnulib module: pthread-spin
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_spin_trylock
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_spin_trylock.html
Gnulib module: pthread-spin
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_spin_unlock
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_spin_unlock.html
Gnulib module: pthread-spin
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_testcancel
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_testcancel.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
ptsname
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ptsname.html
Gnulib module: ptsname
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
Note that the Gnulib module ptsname_r
is a version of this
function that is more likely to be thread-safe.
putc
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/putc.html
Gnulib module: stdio, nonblocking, sigpipe
Portability problems fixed by Gnulib module stdio
, together with module nonblocking
:
errno
being set to ENOSPC
instead of EAGAIN
on some
platforms:
mingw, MSVC 14.
Portability problems fixed by Gnulib module stdio
, together with module sigpipe
:
SIGPIPE
handler, on some platforms:
mingw, MSVC 14.
Portability problems not fixed by Gnulib:
errno
upon failure.
errno
or the
stream error indicator on attempts to write to a read-only stream:
Cygwin 1.7.9.
putc_unlocked
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/putc_unlocked.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
errno
or the
stream error indicator on attempts to write to a read-only stream:
Cygwin 1.7.9.
putchar
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/putchar.html
Gnulib module: stdio, nonblocking, sigpipe
Portability problems fixed by Gnulib module stdio
, together with module nonblocking
:
errno
being set to ENOSPC
instead of EAGAIN
on some
platforms:
mingw, MSVC 14.
Portability problems fixed by Gnulib module stdio
, together with module sigpipe
:
SIGPIPE
handler, on some platforms:
mingw, MSVC 14.
Portability problems not fixed by Gnulib:
errno
upon failure.
errno
or the
stream error indicator on attempts to write to a read-only stream:
Cygwin 1.7.9.
putchar_unlocked
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/putchar_unlocked.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
errno
or the
stream error indicator on attempts to write to a read-only stream:
Cygwin 1.7.9.
putenv
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/putenv.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
Extension: Gnulib provides a module ‘putenv’ that substitutes a
putenv
implementation that can also be used to remove environment
variables.
putmsg
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/putmsg.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
putpmsg
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/putpmsg.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
puts
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/puts.html
Gnulib module: stdio, nonblocking, sigpipe
Portability problems fixed by Gnulib module stdio
, together with module nonblocking
:
errno
being set to ENOSPC
instead of EAGAIN
on some
platforms:
mingw, MSVC 14.
Portability problems fixed by Gnulib module stdio
, together with module sigpipe
:
SIGPIPE
handler, on some platforms:
mingw, MSVC 14.
Portability problems not fixed by Gnulib:
errno
upon failure.
errno
or the
stream error indicator on attempts to write to a read-only stream:
Cygwin 1.7.9.
pututxline
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pututxline.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
putwc
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/putwc.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
errno
or the
stream error indicator on attempts to write to a read-only stream:
Cygwin 1.7.9.
putwchar
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/putwchar.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
errno
or the
stream error indicator on attempts to write to a read-only stream:
Cygwin 1.7.9.
pwrite
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pwrite.html
Gnulib module: pwrite
Portability problems fixed by Gnulib:
off_t
is a 32-bit type, this function may not
work correctly on files 2 GiB and larger. See Large File Support.
off_t
argument
when large file support is enabled on some platforms:
HP-UX 11.11.
Portability problems not fixed by Gnulib:
qsort
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/qsort.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
quick_exit
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
raise
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/raise.html
Gnulib module: raise
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
rand
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/rand.html
Gnulib module: rand
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
rand_r
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/rand_r.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
random_r
from Gnulib module random_r
instead.
random
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/random.html
Gnulib module: random
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
read
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/read.html
Gnulib module: read, stdio, nonblocking
Portability problems fixed by Gnulib module read
:
<io.h>
)
on some platforms:
mingw, MSVC 14.
Portability problems fixed by Gnulib module stdio
, together with module nonblocking
:
errno
being set to EINVAL
instead of EAGAIN
on
some platforms:
mingw, MSVC 14.
Portability problems not fixed by Gnulib:
EINTR
, even in programs that don’t
install any signal handlers, on some platforms:
macOS 11.1.
For handling EINTR
, Gnulib provides a module ‘safe-read’ with a
function safe_read
.
readdir
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/readdir.html
Gnulib module: readdir
Portability problems fixed by Gnulib:
off_t
is a 32-bit type, this function may not
work correctly on huge directories 2 GiB and larger. Also, on platforms
where ino_t
is a 32-bit type, this function may report inode numbers
incorrectly. This can occur with file systems such as XFS (typically on
large disks) and NFS. See Large File Support.
Portability problems not fixed by Gnulib:
d_ino
values, some
older systems are rumored to return d_ino
values equal to zero
for directory entries that do not really exist. Although Gnulib
formerly attempted to cater to these older systems, this caused
misbehavior on standard systems and so Gnulib does not attempt to
cater to them any more. If you know of any problems caused by this,
please send a bug report.
readdir_r
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/readdir_r.html
Gnulib module: extensions
Portability problems fixed by Gnulib:
readdir
.
_POSIX_PTHREAD_SEMANTICS
is not defined).
off_t
is a 32-bit type, this function may not
work correctly on huge directories 2 GiB and larger. Also, on platforms
where ino_t
is a 32-bit type, this function may report inode numbers
incorrectly. This can occur with file systems such as XFS (typically on
large disks) and NFS. See Large File Support.
Portability problems not fixed by Gnulib:
readlink
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/readlink.html
Gnulib module: readlink
Portability problems fixed by Gnulib:
int
instead of
ssize_t
:
glibc 2.4, FreeBSD 6.0, OpenBSD 6.7, Cygwin 1.5.x, AIX 7.1.
Portability problems mostly fixed by Gnulib:
errno
to
ERANGE
rather than returning truncated contents:
AIX 7.2, HP-UX 11.
The Gnulib replacement normally works as POSIX requires by returning
the truncated contents. However, if the full link contents are
unreasonably large (more than 4000 bytes) the replacement clears the
entire buffer and returns the buffer size; although this is not a
complete fix, it suffices for typical callers, which ignore the buffer
contents anyway.
Portability problems not fixed by Gnulib:
errno
to ENOENT
or EIO
instead of
EINVAL
. To avoid this problem, check for a directory before calling
this function.
errno
to ENXIO
instead of EINVAL
. Cygwin
may set errno to EACCES
instead of EINVAL
.
errno
to EINVAL
:
AIX 7.2.
errno
to EINVAL
if the
requested length is zero. Use the gnulib module areadlink
for
improved ability to read symlink contents.
readlinkat
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/readlinkat.html
Gnulib module: readlinkat
Portability problems fixed by Gnulib:
int
instead of
ssize_t
:
AIX 7.1.
Portability problems mostly fixed by Gnulib:
errno
to
ERANGE
rather than returning truncated contents:
AIX 7.2.
The Gnulib replacement normally works as POSIX requires by returning
the truncated contents. However, if the full link contents are
unreasonably large (more than 4000 bytes) the replacement clears the
entire buffer and returns the buffer size; although this is not a
complete fix, it suffices for typical callers, which ignore the buffer
contents anyway.
Portability problems not fixed by Gnulib:
errno
to ENOENT
or EIO
instead of
EINVAL
. To avoid this problem, check for a directory before calling
this function.
errno
to ENXIO
instead of EINVAL
. Cygwin
may set errno to EACCES
instead of EINVAL
.
errno
to EINVAL
:
AIX 7.2.
EBADF
instead of ENOENT
:
Cygwin 3.4.6.
errno
to EINVAL
if the
requested length is zero. Use the gnulib module areadlink
for
improved ability to read symlink contents.
readv
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/readv.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
realloc
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/realloc.html
Gnulib module: realloc-posix
Portability problems fixed by Gnulib:
errno
to ENOMEM
on
some platforms:
mingw, MSVC 14.
realloc (p, n)
can succeed even if n
exceeds PTRDIFF_MAX
. Although this behavior is arguably
allowed by POSIX it can lead to behavior not defined by POSIX later,
so realloc-posix
does not allow going over the limit.
Without the ‘realloc-gnu’ module described below, it is not portable
to call realloc
with a size of 0. With a
NULL pointer argument, this is the same ambiguity as malloc (0)
on whether a unique zero-size object is created. With a non-NULL
pointer argument p
, C17 says that it is implementation-defined
whether realloc (p, 0)
frees p
.
Behavior varies on whether realloc (p, 0)
always frees p
and successfully returns a null pointer, or always
fails and leaves p
valid, or usually succeeds and returns a
unique zero-size object; a program not suspecting these variations in
semantics will leak memory (either the still-valid p
, or the
non-NULL return value).
Extension: Gnulib provides a module ‘realloc-gnu’ that substitutes a
realloc
implementation that behaves more like the glibc implementation.
It fixes these portability problems:
realloc (NULL, 0)
returns NULL
on success on some platforms:
AIX 7.2.
realloc (p, 0)
with non-null p
might not free p
, or might clobber errno
,
or might not return NULL
.
realpath
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/realpath.html
Gnulib module: canonicalize-lgpl
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
recv
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/recv.html
Gnulib module: recv
Portability problems fixed by Gnulib:
errno
, and WSAGetLastError
must be used
instead.
Portability problems not fixed by Gnulib:
recvfrom
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/recvfrom.html
Gnulib module: recvfrom
Portability problems fixed by Gnulib:
errno
, and WSAGetLastError
must be used
instead.
_HPUX_ALT_XOPEN_SOCKET_API
is not defined, this function behaves incorrectly because it is declared
to take a pointer to a 64-bit wide socklen_t
entity but in fact
considers it as a pointer to a 32-bit wide unsigned int
entity.
Portability problems not fixed by Gnulib:
socklen_t
type; in this case this function’s
sixth argument type is ‘int *’.
recvmsg
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/recvmsg.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
regcomp
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/regcomp.html
Gnulib module: regex
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
regerror
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/regerror.html
Gnulib module: regex
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
regexec
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/regexec.html
LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-regexec-2.html
Gnulib module: regex
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
regfree
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/regfree.html
Gnulib module: regex
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
remainder
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/remainder.html
Gnulib module: remainder or remainder-ieee
Portability problems fixed by either Gnulib module remainder
or remainder-ieee
:
Portability problems fixed by Gnulib module remainder-ieee
:
Portability problems not fixed by Gnulib:
remainderf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/remainderf.html
Gnulib module: remainderf or remainderf-ieee
Portability problems fixed by either Gnulib module remainderf
or remainderf-ieee
:
Portability problems fixed by Gnulib module remainderf-ieee
:
Portability problems not fixed by Gnulib:
remainderl
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/remainderl.html
Gnulib module: remainderl or remainderl-ieee
Portability problems fixed by either Gnulib module remainderl
or remainderl-ieee
:
Portability problems fixed by Gnulib module remainderl-ieee
:
Portability problems not fixed by Gnulib:
remove
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/remove.html
Gnulib module: remove
Portability problems fixed by Gnulib:
remove("dir/./")
on some platforms:
Cygwin 1.5.x.
Portability problems not fixed by Gnulib:
remque
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/remque.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
remquo
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/remquo.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
remquof
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/remquof.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
remquol
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/remquol.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
rename
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/rename.html
Gnulib module: rename
Portability problems fixed by Gnulib:
rename("dir","new/")
:
NetBSD 1.6.
rename("file","new/")
:
AIX 7.1, Solaris 11.3, Cygwin 1.5.x, mingw, MSVC 14.
rename("link-to-file/","f")
:
FreeBSD 7.2.
rename("link/","new")
corrupts link:
Solaris 9.
Portability problems not fixed by Gnulib:
rename("symlink-to-dir/","dir2")
rename
dir and leave symlink-to-dir dangling; likewise, it
requires that rename("dir","dangling/")
rename dir so
that dangling is no longer a dangling symlink. This behavior
is counter-intuitive, so on some systems, rename
fails with
ENOTDIR
if either argument is a symlink with a trailing slash:
glibc, OpenBSD, Cygwin 1.7.
rename
do nothing and return 0 if the
source and destination are hard links to the same file. This behavior
is counterintuitive, and on some systems renameat
is a no-op in
this way only if the source and destination identify the same
directory entry. On these systems, for example, although renaming
./f to f is a no-op, renaming f to g
deletes f when f and g are hard links to the same
file:
NetBSD 7.0.
stat
function
for 30 seconds after the rename, on NFS file systems, on some platforms:
Linux 2.6.18.
renameat
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/renameat.html
Gnulib module: renameat
Portability problems fixed by Gnulib:
<unistd.h>
, not in <stdio.h>
,
on some platforms:
NetBSD 7.0, Solaris 11.4.
<sys/stat.h>
, not in <stdio.h>
,
on some platforms:
Android 4.3.
renameat(fd,"file",fd,"new/")
:
Solaris 11.4.
renameat(fd,"link/",fd,"new")
corrupts link:
Solaris 9.
Portability problems not fixed by Gnulib:
renameat(fd,"symlink-to-dir/",fd,"dir2")
rename
dir and leave symlink-to-dir dangling; likewise, it
requires that renameat(fd,"dir",fd,"dangling/")
rename dir so
that dangling is no longer a dangling symlink. This behavior
is counter-intuitive, so on some systems, renameat
fails with
ENOTDIR
if either argument is a symlink with a trailing slash:
glibc, OpenBSD, Cygwin 1.7.
renameat
do nothing and return 0 if the
source and destination are hard links to the same file. This behavior
is counterintuitive, and on some systems renameat
is a no-op in
this way only if the source and destination identify the same
directory entry. On these systems, for example, although renaming
./f to f is a no-op, renaming f to g
deletes f when f and g are hard links to the same
file:
NetBSD 7.0.
stat
function
for 30 seconds after the rename, on NFS file systems, on some platforms:
Linux 2.6.18.
rewind
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/rewind.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
errno
upon failure.
rewinddir
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/rewinddir.html
Gnulib module: rewinddir
Portability problems fixed by Gnulib:
long int
is a 32-bit type, this function may
not work correctly on huge directories 2 GiB and larger.
See Large File Support.
Portability problems not fixed by Gnulib:
rint
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/rint.html
Gnulib module: rint
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
rintf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/rintf.html
Gnulib module: rintf
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
rintl
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/rintl.html
Gnulib module: rintl
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
rmdir
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/rmdir.html
Gnulib module: rmdir
Portability problems fixed by Gnulib:
<io.h>
or
<direct.h>
) on some platforms:
mingw, MSVC 14.
rmdir("dir/./")
on some platforms:
Cygwin 1.5.x.
EINVAL
instead of the expected
ENOTDIR
for rmdir("file/")
on some platforms:
mingw, MSVC 14.
Portability problems not fixed by Gnulib:
rmdir
fails because the specified directory is not empty, the
errno
value is system dependent.
rmdir("link-to-empty/")
remove empty
and leave link-to-empty as a dangling symlink. This is
counter-intuitive, so some systems fail with ENOTDIR
instead:
glibc
round
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/round.html
Gnulib module: round or round-ieee
Portability problems fixed by either Gnulib module round
or round-ieee
:
Portability problems fixed by Gnulib module round-ieee
:
Portability problems not fixed by Gnulib:
roundeven
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/Rounding-Functions.html.
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
roundevenf
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/Rounding-Functions.html.
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
roundevenl
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/Rounding-Functions.html.
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
roundf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/roundf.html
Gnulib module: roundf or roundf-ieee
Portability problems fixed by either Gnulib module roundf
or roundf-ieee
:
Portability problems fixed by Gnulib module roundf-ieee
:
Portability problems not fixed by Gnulib:
roundl
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/roundl.html
Gnulib module: roundl or roundl-ieee
Portability problems fixed by either Gnulib module roundl
or roundl-ieee
:
Portability problems fixed by Gnulib module roundl-ieee
:
Portability problems not fixed by Gnulib:
scalbln
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/scalbln.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
scalblnf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/scalblnf.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
scalblnl
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/scalblnl.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
scalbn
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/scalbn.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
scalbnf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/scalbnf.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
scalbnl
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/scalbnl.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
scandir
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/scandir.html
Gnulib module: scandir
Portability problems fixed by Gnulib:
off_t
is a 32-bit type, this function may not
work correctly on huge directories 2 GiB and larger. Also, on platforms
where ino_t
is a 32-bit type, this function may report inode numbers
incorrectly. See Large File Support.
Portability problems not fixed by Gnulib:
int (*) (const void *, const void *)
on some platforms:
glibc 2.3.6, macOS 10.7, FreeBSD 6.0, NetBSD 7.1, OpenBSD 6.7.
int (*) (void *, void *)
on some platforms:
AIX 5.1.
scanf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/scanf.html
LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-scanf.html
Gnulib module: stdio, nonblocking
Portability problems fixed by Gnulib module stdio
, together with module nonblocking
:
errno
being set to EINVAL
instead of EAGAIN
on
some platforms:
mingw, MSVC 14.
Portability problems not fixed by Gnulib:
feof
would return nonzero. However, on some systems this
function attempts to read from the underlying file descriptor even if
the stream’s end-of-file indicator is set. These systems include
glibc and default Solaris.
errno
upon failure.
hh
, ll
, j
,
t
, z
size specifiers.
sched_get_priority_max
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sched_get_priority_max.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
sched_get_priority_min
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sched_get_priority_min.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
sched_getparam
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sched_getparam.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
sched_getscheduler
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sched_getscheduler.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
sched_rr_get_interval
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sched_rr_get_interval.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
sched_setparam
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sched_setparam.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
sched_setscheduler
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sched_setscheduler.html
LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-sched-setscheduler.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
sched_yield
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sched_yield.html
Gnulib module: sched_yield
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
seed48
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/seed48.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
seekdir
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/seekdir.html
Gnulib module: —
Portability problems fixed by Gnulib:
long int
is a 32-bit type, this function may not
work correctly on huge directories 2 GiB and larger.
See Large File Support.
Portability problems not fixed by Gnulib:
select
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/select.html
Gnulib module: select
Portability problems fixed by Gnulib:
select
can only be
called on descriptors created by the socket
function, not on regular
file descriptors.
errno
, and WSAGetLastError
must be used
instead.
Portability problems not fixed by Gnulib:
select
with a timeout, some implementations modify the
timeout parameter so that upon return from the function, it contains the
amount of time not slept. Other implementations leave the timeout parameter
unmodified.
select
replacement might
return 0 even before the timeout has passed. Programs using it with pipes can
thus busy wait.
select
may fail, setting errno
to EBADF
.
sem_close
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sem_close.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
sem_destroy
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sem_destroy.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
sem_getvalue
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sem_getvalue.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
sem_init
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sem_init.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
sem_open
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sem_open.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
sem_post
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sem_post.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
sem_timedwait
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sem_timedwait.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
sem_trywait
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sem_trywait.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
sem_unlink
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sem_unlink.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
sem_wait
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sem_wait.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
semctl
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/semctl.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
semget
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/semget.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
semop
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/semop.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
send
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/send.html
Gnulib module: send
Portability problems fixed by Gnulib:
errno
, and WSAGetLastError
must be used
instead.
Portability problems not fixed by Gnulib:
sendmsg
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sendmsg.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
sendto
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sendto.html
Gnulib module: sendto
Portability problems fixed by Gnulib:
errno
, and WSAGetLastError
must be used
instead.
Portability problems not fixed by Gnulib:
setbuf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/setbuf.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
setegid
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/setegid.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
setenv
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/setenv.html
Gnulib module: setenv
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
setenv(NULL,"",0)
gracefully
fail with EINVAL
, but not all implementations guarantee this,
and the requirement was removed.
seteuid
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/seteuid.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
setgid
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/setgid.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
setgrent
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/setgrent.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
sethostent
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sethostent.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
setitimer
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/setitimer.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
timer_create
and timer_settime
instead.
setjmp
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/setjmp.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
setjmp
saves the signal mask in the
jmp_buf
. It does on BSD platforms, and on glibc platforms when
_BSD_SOURCE
(and/or _DEFAULT_SOURCE
on glibc >= 2.19) is defined;
in this case setjmp
behaves like sigsetjmp(.,1)
, and functions
_setjmp
and _longjmp
are available that don’t save or restore
the signal mask. On System V platforms (excluding HP-UX), and on glibc
platforms by default, setjmp
doesn’t save the signal mask.
setkey
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/setkey.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<stdlib.h>
(without -D_GNU_SOURCE
) on some platforms:
glibc (at least 2.11–2.13).
setlocale
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/setlocale.html
Gnulib module: setlocale, setlocale-null
Portability problems fixed by Gnulib module setlocale
:
setlocale(category,NULL)
ignores the environment variables LC_ALL
, category
, and
LANG
.
setlocale(LC_ALL,name)
succeeds and sets the LC_CTYPE category to
‘C’ when it does not support the encoding, instead of failing.
setlocale
understands different
locale names, that are not based on ISO 639 language names and ISO 3166 country
names.
setlocale
function
always fails. The replacement, however, supports only the locale names
"C"
and "POSIX"
.
Portability problems fixed by Gnulib module setlocale
or setlocale-null
:
setlocale (..., NULL)
are not multithread-safe on some
platforms:
musl libc, macOS, FreeBSD, NetBSD, OpenBSD, AIX, Haiku, Cygwin.
To make these invocations multithread-safe, you need the Gnulib module
setlocale
, or you need to change the code to invoke setlocale_null
or setlocale_null_r
instead.
Portability problems not fixed by Gnulib:
setlocale(LC_ALL,NULL)
always returns "C"
.
setlocale(LC_ALL,"")
will only update categories that
are deemed appropriate for the LC_ALL
environment value, even if
there are other categories set to different values in the environment.
In addition any value is accepted for LC_CTYPE
, and so NULL
is never returned to indicate a failure to set locale.
To verify category values, each category must be set individually
with setlocale(LC_COLLATE,"")
etc.
setlocale
was not called) is the "C.UTF-8"
locale, not the
"C"
locale. Additionally, a setlocale
call that is meant to set
the "C"
or "POSIX"
locale actually sets an equivalent of the
"C.UTF-8"
locale.
setlogmask
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/setlogmask.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
setnetent
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/setnetent.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
setpayload
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/FP-Bit-Twiddling.html.
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
setpayloadf
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/FP-Bit-Twiddling.html.
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
setpayloadl
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/FP-Bit-Twiddling.html.
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
setpayloadsig
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/FP-Bit-Twiddling.html.
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
setpayloadsigf
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/FP-Bit-Twiddling.html.
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
setpayloadsigl
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/FP-Bit-Twiddling.html.
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
setpgid
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/setpgid.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
setpgrp
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/setpgrp.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
setpgid
or setsid
instead, as appropriate.
setpriority
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/setpriority.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
setprotoent
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/setprotoent.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
setpwent
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/setpwent.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
setregid
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/setregid.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
setreuid
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/setreuid.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
setrlimit
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/setrlimit.html
LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-getrlimit-1.html
Gnulib module: —
Portability problems fixed by Gnulib:
rlim_t
is a 32-bit type, this function does not
allow to set limits 4 GiB and larger, such as for RLIMIT_FSIZE.
See Large File Support.
Portability problems not fixed by Gnulib:
setservent
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/setservent.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
setsid
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/setsid.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
setsockopt
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/setsockopt.html
LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-setsockopt-2.html
Gnulib module: setsockopt
Portability problems fixed by Gnulib:
errno
, and WSAGetLastError
must be used
instead.
Portability problems not fixed by Gnulib:
setstate
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/setstate.html
Gnulib module: random
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
setuid
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/setuid.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
setutxent
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/setutxent.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
setvbuf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/setvbuf.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
errno
upon failure.
_IOLBF
(line-buffering)
is treated as if it were _IOFBF
(full buffering),
possibly with a warning generated.
shm_open
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/shm_open.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
shm_unlink
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/shm_unlink.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
shmat
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/shmat.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
SHM_REMAP
is needed in order to force shmat
to replace existing memory mappings in the specify address range. On other
platforms, it is not needed.
shmctl
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/shmctl.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
shmdt
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/shmdt.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
shmget
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/shmget.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
shmget
requires superuser privileges.
shutdown
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/shutdown.html
Gnulib module: shutdown
Portability problems fixed by Gnulib:
errno
, and WSAGetLastError
must be used
instead.
Portability problems not fixed by Gnulib:
sigaction
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sigaction.html
Gnulib module: sigaction
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
SIG_IGN
for the SIGCHLD
signal is equivalent
to a signal handler
void handle_child (int sigchld) { while (waitpid (-1, NULL, WNOHANG) > 0) ; }
except that SIG_IGN
for SIGCHLD
has the effect that the children
execution times are not accounted in the times
function.
On some platforms (BSD? SystemV? Linux?), you need to use the sigaction
flag SA_NOCLDWAIT
in order to obtain this behavior.
sigaddset
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sigaddset.html
Gnulib module: sigprocmask
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
sigaltstack
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sigaltstack.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
sigaltstack
doesn’t work on HP-UX 11/IA-64 and
OpenBSD 3.6/Sparc64.
ss_sp
member of stack_t
as
the upper bound instead of the lower bound of the alternate stack on
some platforms:
IRIX 6.5
sigdelset
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sigdelset.html
Gnulib module: sigprocmask
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
sigemptyset
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sigemptyset.html
Gnulib module: sigprocmask
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
sigfillset
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sigfillset.html
Gnulib module: sigprocmask
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
sighold
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sighold.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
sigprocmask
instead.
sigignore
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sigignore.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
sigaction
instead.
siginterrupt
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/siginterrupt.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
sigaction
instead.
Note: POSIX recommends using sigaction
with SA_RESTART instead of
siginterrupt (sig, 0)
.
sigismember
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sigismember.html
Gnulib module: sigprocmask
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
siglongjmp
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/siglongjmp.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
signal
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/signal.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
sigaction
instead of
signal
.
signbit
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/signbit.html
Gnulib module: signbit
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
signgam
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/signgam.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
sigpause
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sigpause.html
LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-sigpause-3.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
sigsuspend
instead.
sigpending
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sigpending.html
Gnulib module: sigprocmask
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
sigprocmask
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sigprocmask.html
Gnulib module: sigprocmask
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
Note: Although sigprocmask
officially has undefined behaviour in
multi-threaded programs, in practice it is essentially equivalent to
pthread_sigmask
, with only a difference regarding the error
return convention. It’s simpler to use sigprocmask
, since it does
not require linking with -lpthread
on some platforms:
glibc, NetBSD, OpenBSD, AIX, IRIX.
sigqueue
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sigqueue.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
sigrelse
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sigrelse.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
sigprocmask
instead.
sigset
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sigset.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
sigaction
instead.
sigsetjmp
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sigsetjmp.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
sigsuspend
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sigsuspend.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
sigtimedwait
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sigtimedwait.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
sigwaitinfo
does; other platforms may not do the same.
sigwait
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sigwait.html
Gnulib module: extensions
Portability problems fixed by Gnulib:
_POSIX_PTHREAD_SEMANTICS
is not defined).
Portability problems not fixed by Gnulib:
sigwaitinfo
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sigwaitinfo.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
sin
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sin.html
Gnulib module: sin
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
sinf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sinf.html
Gnulib module: sinf
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
sinh
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sinh.html
Gnulib module: sinh
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
sinhf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sinhf.html
Gnulib module: sinhf
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
sinhl
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sinhl.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
sinl
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sinl.html
Gnulib module: sinl
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
sleep
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sleep.html
Gnulib module: sleep
Portability problems fixed by Gnulib:
void
on some
platforms:
mingw (2005 and older).
Portability problems not fixed by Gnulib:
sleep
function may interfere with the program’s
use of the SIGALRM
signal. On Linux, it doesn’t; on other platforms,
it may.
snprintf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/snprintf.html
Gnulib module: snprintf or snprintf-posix or snprintf-gnu
Portability problems fixed by either Gnulib module snprintf
or snprintf-posix
or snprintf-gnu
:
"%2$s"
, on some platforms:
NetBSD 3.0, mingw.
Portability problems fixed by either Gnulib module snprintf-posix
or snprintf-gnu
:
hh
, ll
,
j
, t
, z
) on some platforms:
AIX 5.1, HP-UX 11.23, IRIX 6.5, Solaris 9, Cygwin 1.5.24, old mingw, MSVC 9.
w8
,
w16
, w32
, w64
, wf8
, wf16
, wf32
,
wf64
) on some platforms:
glibc, musl libc, macOS 12.5, FreeBSD 13.1, NetBSD 9.0, OpenBSD 7.2,
AIX 7.2, HP-UX 11, IRIX 6.5, Solaris 11.4, Cygwin 2.9.0, mingw.
"%f"
, "%e"
, "%g"
of Infinity and NaN yields an
incorrect result on some platforms:
AIX 5.2, Solaris 11.4, mingw, MSVC 14.
_FORTIFY_SOURCE >= 2
(set by default on Ubuntu),
Android, OpenBSD, macOS 11.1, MSVC 14.
'
flag on some platforms:
NetBSD 3.0, Cygwin 1.5.24, mingw, MSVC 14.
"%010f"
of NaN and Infinity yields an incorrect result (padded
with zeroes, or wrong capitalization) on some platforms:
Mac OS X 10.5, FreeBSD 6.0, NetBSD 5.0, AIX 5.2, IRIX 6.5, Solaris 11.4, Cygwin 1.5.x, mingw, MSVC/clang.
"%#.0x"
or "%#.0X"
with a zero argument yields an
incorrect result (non-empty) on some platforms:
Mac OS X 10.6.
Portability problems fixed by Gnulib module snprintf-gnu
:
Portability problems not fixed by Gnulib:
%m
directive is not portable, use %s
mapped to an
argument of strerror(errno)
(or a version of strerror_r
)
instead.
sockatmark
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sockatmark.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
socket
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/socket.html
Gnulib module: socket
Portability problems fixed by Gnulib:
socket
function cannot be used in calls to read
,
write
, and close
; you have to use recv
, send
,
closesocket
in these cases instead.
errno
, and WSAGetLastError
must be used
instead.
Portability problems not fixed by Gnulib:
socketpair
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/socketpair.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
sprintf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sprintf.html
Gnulib module: sprintf-posix or sprintf-gnu
Portability problems fixed by either Gnulib module sprintf-posix
or sprintf-gnu
:
hh
, ll
,
j
, t
, z
) on some platforms:
AIX 5.1, HP-UX 11.23, IRIX 6.5, Solaris 9, Cygwin 1.5.24, old mingw, MSVC 9.
w8
,
w16
, w32
, w64
, wf8
, wf16
, wf32
,
wf64
) on some platforms:
glibc, musl libc, macOS 12.5, FreeBSD 13.1, NetBSD 9.0, OpenBSD 7.2,
AIX 7.2, HP-UX 11, IRIX 6.5, Solaris 11.4, Cygwin 2.9.0, mingw, MSVC 14.
"%f"
, "%e"
, "%g"
of Infinity and NaN yields an
incorrect result on some platforms:
AIX 5.2, Solaris 11.4, mingw, MSVC 14.
_FORTIFY_SOURCE >= 2
(set by default on Ubuntu),
Android, OpenBSD, macOS 11.1, MSVC 14.
"%2$s"
, on some platforms:
NetBSD 3.0, mingw, MSVC 14.
'
flag on some platforms:
NetBSD 3.0, Cygwin 1.5.24, mingw, MSVC 14.
"%010f"
of NaN and Infinity yields an incorrect result (padded
with zeroes, or wrong capitalization) on some platforms:
Mac OS X 10.5, FreeBSD 6.0, NetBSD 5.0, AIX 5.2, IRIX 6.5, Solaris 11.4, Cygwin 1.5.x, mingw, MSVC/clang.
"%#.0x"
or "%#.0X"
with a zero argument yields an
incorrect result (non-empty) on some platforms:
Mac OS X 10.6.
Portability problems fixed by Gnulib module sprintf-gnu
:
Portability problems not fixed by Gnulib:
%m
directive is not portable, use %s
mapped to an
argument of strerror(errno)
(or a version of strerror_r
)
instead.
sqrt
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sqrt.html
Gnulib module: sqrt
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
sqrtf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sqrtf.html
Gnulib module: sqrtf
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
sqrtl
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sqrtl.html
Gnulib module: sqrtl
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
srand
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/srand.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
srand48
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/srand48.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
srandom
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/srandom.html
Gnulib module: random
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
unsigned long
instead of unsigned int
on some
platforms:
MidnightBSD 2.0.
sscanf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sscanf.html
LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-sscanf.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
errno
upon failure.
hh
, ll
, j
,
t
, z
size specifiers.
stat
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/stat.html
Gnulib module: stat
Portability problems fixed by Gnulib:
off_t
is a 32-bit type, stat
may not correctly
report the size of files or block devices 2 GiB and larger.
See Large File Support.
st_atime
, st_ctime
, st_mtime
fields are affected by
the current time zone and by the DST flag of the current time zone on some
platforms:
mingw, MSVC 14 (when the environment variable TZ
is set).
ENOENT
on files such as ‘C:\pagefile.sys’ and
on directories such as ‘C:\System Volume Information’.
stat("link-to-file/",buf)
succeeds instead
of failing with ENOTDIR
.
macOS 11.1, FreeBSD 7.2, AIX 7.1, Solaris 9, mingw64.
stat(".",buf)
and stat("./",buf)
give
different results:
mingw, MSVC 14.
tv_sec
value, tv_nsec
might be in the range
−1000000000..−1, representing a negative nanoseconds
offset from tv_sec
.
Portability problems not fixed by Gnulib:
struct stat
.
stat
function sometimes sets errno
to EACCES
when
ENOENT
would be more appropriate.
struct stat
, it is not possible to
portably replace stat
via an object-like macro. Therefore,
expressions such as (islnk ? lstat : stat) (name, buf)
are not
portable, and should instead be written islnk ? lstat (name,
buf) : stat (name, buf)
.
statvfs
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/statvfs.html
Gnulib module: —
Portability problems fixed by Gnulib:
f_blocks
in ‘struct statvfs’ is a 32-bit
value, this function may not work correctly on files systems larger than
4 TiB. See Large File Support. This affects
glibc/Hurd, HP-UX 11, Solaris.
Portability problems not fixed by Gnulib:
Gnulib provides a module fsusage
that provides similar information
as statvfs
.
stderr
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/stderr.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
ftello
module and do
ftello(stderr).
stderr
can affect an unrelated file that happened to be assigned to fd 2.
The gnulib *-safer modules may be used to guarantee that fd 2 stays
reserved for stderr
.
stdin
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/stdin.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
stdin
can affect an unrelated file that happened to be assigned to fd 0.
The gnulib *-safer modules may be used to guarantee that fd 0 stays
reserved for stdin
.
stdout
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/stdout.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
ftello
module and do
ftello(stdout).
stdout
can affect an unrelated file that happened to be assigned to fd 1.
The gnulib *-safer modules may be used to guarantee that fd 1 stays
reserved for stdout
.
stpcpy
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/stpcpy.html
Gnulib module: stpcpy
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
stpncpy
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/stpncpy.html
Gnulib module: stpncpy
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
strcasecmp
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strcasecmp.html
Gnulib module: strcase
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
mbscasecmp
that does a case
insensitive comparison of character strings and that works in all locales.
strcasecmp_l
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strcasecmp_l.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
strcat
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strcat.html
Gnulib module: string
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
strchr
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strchr.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
mbschr
that works on
character strings in all locales.
strcmp
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strcmp.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
strcoll
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strcoll.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
errno
to EILSEQ
, on Solaris 10, in
UTF-8 locales, when at least one of the strings contains a Unicode character
in a block that was not assigned in Unicode 4.0.
strcoll_l
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strcoll_l.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
strcpy
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strcpy.html
Gnulib module: string
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
Note: strcpy (dst, src)
is only safe to use when you can guarantee that
there are at least strlen (src) + 1
bytes allocated at dst
.
strcspn
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strcspn.html
Gnulib module: strcspn
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
mbscspn
that works on character
strings in all locales.
strdup
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strdup.html
Gnulib module: strdup or strdup-posix
Portability problems fixed by either Gnulib module strdup
or strdup-posix
:
<string.h>
on some old platforms.
Portability problems fixed by Gnulib module strdup-posix
:
errno
to ENOMEM
on
some platforms:
mingw, MSVC 14.
Portability problems not fixed by Gnulib:
strerror
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strerror.html
Gnulib module: strerror
Portability problems fixed by Gnulib:
strerror(0)
(by setting
errno
or using a string similar to out-of-range values),
although POSIX requires this to leave errno
unchanged and
report success, on some platforms:
FreeBSD 8.2, NetBSD 9.0, OpenBSD 4.7, macOS 11.1.
strerror
without setting and testing
errno
.)
Portability problems not fixed by Gnulib:
strerror_l
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strerror_l.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
strerror_r
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strerror_r.html
LSB specification:
Gnulib module: strerror_r-posix
Portability problems fixed by Gnulib:
char *s = (strerror_r (err, buf, buflen) == 0 ? buf : NULL);
is essentially equivalent to this code using the glibc function:
char *s = strerror_r (err, buf, buflen);
strerror
buffer on some platforms:
Cygwin 1.7.9.
<string.h>
on some platforms:
glibc 2.8.
int
instead of size_t
on some
platforms:
AIX 5.1.
errno
, instead of
returning the error number, on some platforms:
glibc 2.12 with -D_POSIX_C_SOURCE=200112L
, AIX 6.1.
errno
, on some platforms:
Solaris 10.
<errno.h>
on
some platforms:
MSVC 14.
strerror_r(0, buf, len)
,
although POSIX requires this to succeed, on some platforms:
FreeBSD 8.2.
0
than
strerror
on some platforms:
macOS 11.1.
Portability problems not fixed by Gnulib:
Note: Gnulib has a module xstrerror
, with the property that
xstrerror (NULL, errnum)
returns the value of strerror_r
as a freshly allocated string.
(Recall that the expression strerror (errnum)
is not multithread-safe.)
strfmon
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strfmon.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
strfmon_l
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strfmon_l.html
Gnulib module: strfmon_l
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
strfromd
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
strfromf
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
strfroml
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
strftime
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strftime.html
Gnulib module: strftime-fixes
Portability problems fixed by Gnulib:
TZ
has been set by Cygwin.
Portability problems not fixed by Gnulib:
tzset
.
Extension: Gnulib offers a module ‘nstrftime’ that provides an
nstrftime
function with various GNU extensions.
strftime_l
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strftime_l.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
strlen
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strlen.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
strncasecmp
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strncasecmp.html
Gnulib module: strcase
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
mbsncasecmp
and mbspcasecmp
that do a case insensitive comparison of character strings and that work in all
locales.
strncasecmp_l
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strncasecmp_l.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
strncat
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strncat.html
Gnulib module: strncat
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
strncmp
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strncmp.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
strncpy
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strncpy.html
Gnulib module: string
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
Note: This function was designed for the use-case of filling a fixed-size record with a string, before writing it to a file. This function is not appropriate for copying a string into a bounded memory area, because you have no guarantee that the result will be NUL-terminated. Even if you add the NUL byte at the end yourself, this function is inefficient (as it spends time clearing unused memory) and will allow silent truncation to occur, which is not a good behavior for GNU programs. For more details, see https://meyering.net/crusade-to-eliminate-strncpy/.
strndup
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strndup.html
Gnulib module: strndup
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
strnlen
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strnlen.html
Gnulib module: strnlen
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
strpbrk
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strpbrk.html
Gnulib module: strpbrk
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
mbspbrk
that works on character
strings in all locales.
strptime
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strptime.html
LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-strptime-3.html
Gnulib module: strptime
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
strrchr
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strrchr.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
mbsrchr
that works
on character strings in all locales.
strsignal
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strsignal.html
Gnulib module: strsignal
Portability problems fixed by Gnulib:
unistd.h
instead of
string.h
on some platforms:
NetBSD 5.0.
Portability problems not fixed by Gnulib:
const char *
instead of char *
on
some platforms:
cygwin 1.5.25.
strspn
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strspn.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
mbsspn
that works on character
strings in all locales.
strstr
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strstr.html
Gnulib module: strstr or strstr-simple
Portability problems fixed by either Gnulib module strstr-simple
or strstr
:
Portability problems fixed by Gnulib module strstr
:
Portability problems not fixed by Gnulib:
mbsstr
that works
on character strings in all locales.
strtod
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strtod.html
Gnulib module: strtod or strtod-obsolete
Portability problems fixed by either Gnulib module strtod
or strtod-obsolete
:
Portability problems fixed by Gnulib module strtod-obsolete
:
Portability problems not fixed by Gnulib:
strtof
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strtof.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
strtoimax
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strtoimax.html
Gnulib module: strtoimax
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
strtok
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strtok.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
strtok_r
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strtok_r.html
Gnulib module: strtok_r
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
mbstok_r
that works on character
strings in all locales.
strtol
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strtol.html
Gnulib module: strtol
Portability problems fixed by Gnulib:
"0x"
and the base is 16 or 0 on some platforms:
Minix 3.3, mingw, MSVC 14.
Portability problems not fixed by Gnulib:
strtold
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strtold.html
Gnulib module: strtold
Portability problems fixed by Gnulib:
long double
, on some platforms:
HP-UX 11.31/hppa.
errno
upon underflow on some platforms:
Cygwin 2.9.
Portability problems not fixed by Gnulib:
strtoll
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strtoll.html
Gnulib module: strtoll
Portability problems fixed by Gnulib:
"0x"
and the base is 16 or 0 on some platforms:
Minix 3.3, mingw, MSVC 14.
Portability problems not fixed by Gnulib:
strtoul
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strtoul.html
Gnulib module: strtoul
Portability problems fixed by Gnulib:
"0x"
and the base is 16 or 0 on some platforms:
Minix 3.3, mingw, MSVC 14.
Portability problems not fixed by Gnulib:
strtoull
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strtoull.html
Gnulib module: strtoull
Portability problems fixed by Gnulib:
"0x"
and the base is 16 or 0 on some platforms:
Minix 3.3, mingw, MSVC 14.
Portability problems not fixed by Gnulib:
strtoumax
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strtoumax.html
Gnulib module: strtoumax
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
strxfrm
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strxfrm.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
strxfrm_l
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strxfrm_l.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
swab
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/swab.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
swprintf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/swprintf.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
_FORTIFY_SOURCE >= 2
(set by default on Ubuntu),
Android, OpenBSD, macOS 11.1, MSVC 14.
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
w8
,
w16
, w32
, w64
, wf8
, wf16
, wf32
,
wf64
) on some platforms:
glibc, musl libc, macOS 12.5, FreeBSD 13.1, NetBSD 9.0, OpenBSD 7.2,
AIX 7.2, HP-UX 11, Solaris 11.4, Cygwin 2.9.0, mingw, MSVC 14.
"%#.0x"
or "%#.0X"
with a zero argument yields an
incorrect result (non-empty) on some platforms:
Mac OS X 10.6.
%m
directive is not portable, use %s
mapped to an
argument of strerror(errno)
(or a version of strerror_r
)
instead.
%c
and %s
conversions may fail
on some platforms:
glibc 2.35, musl libc 1.2.4, FreeBSD 13.2, NetBSD 9.3, OpenBSD 7.2, Cygwin 2.9.0.
%lc
directive may fail on some platforms:
musl libc 1.2.4, FreeBSD 13.2, NetBSD 9.3, OpenBSD 7.2.
swscanf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/swscanf.html
LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-swscanf.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
symlink
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/symlink.html
Gnulib module: symlink
Portability problems fixed by Gnulib:
symlink(value,"name/")
mistakenly creates a
symlink:
macOS 11.1, FreeBSD 7.2, AIX 7.1, Solaris 9.
EPERM
:
mingw, MSVC 14.
Portability problems not fixed by Gnulib:
symlinkat
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/symlinkat.html
Gnulib module: symlinkat
Portability problems fixed by Gnulib:
stdio.h
instead of
unistd.h
:
Cygwin 1.7.1.
symlinkat(value, fd, "name/")
mistakenly creates a
symlink:
macOS 11.1, AIX 7.1.
Portability problems not fixed by Gnulib:
sync
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sync.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
sysconf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sysconf.html
LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-sysconf.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
syslog
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/syslog.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
system
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/system.html
LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-system-3.html
Gnulib module: system-posix
Portability problems fixed by Gnulib:
WIFSIGNALED
, WIFEXITED
, WIFSTOPPED
,
WTERMSIG
, WEXITSTATUS
, WNOHANG
, WUNTRACED
,
WSTOPSIG
are not defined in <stdlib.h>
(only in
<sys/wait.h>
) on some platforms:
MirBSD 10.
Portability problems not fixed by Gnulib:
system
function is cmd.exe, not /bin/sh. Accordingly,
the rules for quoting shell arguments containing spaces, quote or other special
characters are different.
tan
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/tan.html
Gnulib module: tan
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
tanf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/tanf.html
Gnulib module: tanf
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
tanh
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/tanh.html
Gnulib module: tanh
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
tanhf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/tanhf.html
Gnulib module: tanhf
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
tanhl
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/tanhl.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
tanl
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/tanl.html
Gnulib module: tanl
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
tcdrain
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/tcdrain.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
tcdrain
on a non-tty fails with errno
set to
EINVAL
or, on Mac OS X, also EOPNOTSUPP
or ENODEV
, rather
than ENOTTY
.
tcflow
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/tcflow.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
tcflush
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/tcflush.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
tcflush
of TCIFLUSH
on a non-tty fails with
errno set to EINVAL
rather than ENOTTY
.
tcflush
of TCOFLUSH
on a non-tty fails with
errno set to EINVAL
or, on IRIX, also ENOSYS
, or, on Mac OS X,
also EOPNOTSUPP
or ENODEV
, rather than ENOTTY
.
tcgetattr
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/tcgetattr.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
tcgetpgrp
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/tcgetpgrp.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
tcgetsid
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/tcgetsid.html
Gnulib module: tcgetsid
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
tcsendbreak
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/tcsendbreak.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
tcsetattr
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/tcsetattr.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
tcsetpgrp
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/tcsetpgrp.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
tdelete
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/tdelete.html
Gnulib module: tsearch
Portability problems fixed by Gnulib:
tdelete
returns NULL
when removing the last element of a tree
on some platforms:
OpenBSD 4.0.
Portability problems not fixed by Gnulib:
telldir
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/telldir.html
Gnulib module: —
Portability problems fixed by Gnulib:
long int
is a 32-bit type, this function may not
work correctly on huge directories 2 GiB and larger.
See Large File Support.
Portability problems not fixed by Gnulib:
tempnam
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/tempnam.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
mkstemp
instead.
mkstemp
instead.
tfind
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/tfind.html
Gnulib module: tsearch
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
tgamma
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/tgamma.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
tgammaf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/tgammaf.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
tgammal
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/tgammal.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
thrd_create
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/ISO-C-Thread-Management.html.
Gnulib module: thrd
Portability problems fixed by Gnulib:
thrd_start_t
on some platforms:
AIX 7.2.
Portability problems not fixed by Gnulib:
thrd_current
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/ISO-C-Thread-Management.html.
Gnulib module: thrd
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
thrd_detach
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/ISO-C-Thread-Management.html.
Gnulib module: thrd
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
thrd_equal
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/ISO-C-Thread-Management.html.
Gnulib module: thrd
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
thrd_exit
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/ISO-C-Thread-Management.html.
Gnulib module: thrd
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
thrd_join
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/ISO-C-Thread-Management.html.
Gnulib module: thrd
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
thrd_sleep
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/ISO-C-Thread-Management.html.
Gnulib module: thrd
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
thrd_yield
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/ISO-C-Thread-Management.html.
Gnulib module: thrd
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
time
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/time.html
Gnulib module: time
Portability problems fixed by Gnulib:
gettimeofday
and timespec_get
on some platforms:
glibc 2.31 or newer on Linux, AIX 7.2, native Windows.
Namely, in the first 1 to 2.5 milliseconds of every second (or, on AIX and
Windows, in the first 5 milliseconds of every second), time
returns
a value that is one less than the tv_sec
part of the return value of
gettimeofday
or timespec_get
.
Portability problems not fixed by Gnulib:
timegm
¶Documentation:
Gnulib module: timegm
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
timer_create
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/timer_create.html
Gnulib module: timer-time
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
ENOSYS
on some platforms:
OpenBSD 4.9.
timer_delete
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/timer_delete.html
Gnulib module: timer-time
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
ENOSYS
on some platforms:
OpenBSD 4.9.
timer_getoverrun
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/timer_getoverrun.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
timer_gettime
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/timer_gettime.html
Gnulib module: timer-time
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
ENOSYS
on some platforms:
OpenBSD 4.9.
timer_settime
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/timer_settime.html
Gnulib module: timer-time
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
ENOSYS
on some platforms:
OpenBSD 4.9.
times
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/times.html
Gnulib module: times
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
tms_cutime
and tms_cstime
will always be
0 when the module is used.
timespec_getres
¶ISO C23 specification:
http://www.open-std.org/jtc1/sc22/wg14/www/docs/n3047.pdf section 7.29.2.7
Gnulib module: timespec_getres
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
timespec_get
, i.e., the minimum distance between
differing timestamps. For example, on GNU/Linux it typically returns
1 nanosecond regardless of the actual clock resolution.
The Gnulib module gettime-res
is a partial substitute; it implements
the TIME_UTC
functionality of timespec_getres
.
timezone
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/timezone.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
tzset
.
A more portable way of getting the UTC offset is to use
strftime
with the %z
format. See strftime
.
tmpfile
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/tmpfile.html
Gnulib module: tmpfile
Portability problems fixed by Gnulib:
off_t
is a 32-bit type, tmpfile
may not work
correctly to create files 2 GiB and larger. See Large File Support.
Portability problems not fixed by Gnulib:
tmpnam
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/tmpnam.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
mkstemp
instead.
toascii
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/toascii.html
Gnulib module: ctype
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
tolower
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/tolower.html
Gnulib module: ctype
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
Note: This function’s behaviour depends on the locale, but does not support
the multibyte characters that occur in strings in locales with
MB_CUR_MAX > 1
(this includes all the common UTF-8 locales).
There are four alternative APIs:
c_tolower
This function operates in a locale independent way and returns a different value than the argument only for uppercase ASCII characters. It is provided by the Gnulib module ‘c-ctype’.
towlower
This function operates in a locale dependent way, on wide characters. In
order to use it, you first have to convert from multibyte to wide characters,
using the mbrtowc
function. It is provided by the Gnulib module
‘wctype’.
c32tolower
This function operates in a locale dependent way, on 32-bit wide characters.
In order to use it, you first have to convert from multibyte to 32-bit wide
characters, using the mbrtoc32
function. It is provided by the
Gnulib module ‘c32tolower’.
uc_tolower
This function operates in a locale independent way, on Unicode characters. It is provided by the Gnulib module ‘unicase/tolower’.
tolower_l
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/tolower_l.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
totalorder
¶Documentation:
Gnulib module: totalorder
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
totalorderf
¶Documentation:
Gnulib module: totalorderf
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
totalorderl
¶Documentation:
Gnulib module: totalorderl
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
totalordermag
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/FP-Comparison-Functions.html.
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
totalordermagf
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/FP-Comparison-Functions.html.
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
totalordermagl
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/FP-Comparison-Functions.html.
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
toupper
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/toupper.html
Gnulib module: ctype
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
Note: This function’s behaviour depends on the locale, but does not support
the multibyte characters that occur in strings in locales with
MB_CUR_MAX > 1
(this includes all the common UTF-8 locales).
There are four alternative APIs:
c_toupper
This function operates in a locale independent way and returns a different value than the argument only for lowercase ASCII characters. It is provided by the Gnulib module ‘c-ctype’.
towupper
This function operates in a locale dependent way, on wide characters. In
order to use it, you first have to convert from multibyte to wide characters,
using the mbrtowc
function. It is provided by the Gnulib module
‘wctype’.
c32toupper
This function operates in a locale dependent way, on 32-bit wide characters.
In order to use it, you first have to convert from multibyte to 32-bit wide
characters, using the mbrtoc32
function. It is provided by the
Gnulib module ‘c32toupper’.
uc_toupper
This function operates in a locale independent way, on Unicode characters. It is provided by the Gnulib module ‘unicase/toupper’.
toupper_l
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/toupper_l.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
towctrans
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/towctrans.html
Gnulib module: towctrans
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
However, the Gnulib function c32_apply_mapping
, provided by Gnulib
module c32_apply_mapping
, operates on 32-bit wide characters and
therefore does not have this limitation.
towctrans_l
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/towctrans_l.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
towlower
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/towlower.html
Gnulib module: wctype-h
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
However, the Gnulib function c32tolower
, provided by Gnulib module
c32tolower
, operates on 32-bit wide characters and therefore does not
have this limitation.
towlower_l
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/towlower_l.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
towupper
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/towupper.html
Gnulib module: wctype-h
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
However, the Gnulib function c32toupper
, provided by Gnulib module
c32toupper
, operates on 32-bit wide characters and therefore does not
have this limitation.
towupper_l
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/towupper_l.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
trunc
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/trunc.html
Gnulib module: trunc or trunc-ieee
Portability problems fixed by either Gnulib module trunc
or trunc-ieee
:
-D_GNU_SOURCE
) on some platforms:
glibc 2.8.
Portability problems fixed by Gnulib module trunc-ieee
:
Portability problems not fixed by Gnulib:
truncate
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/truncate.html
Gnulib module: truncate
Portability problems fixed by Gnulib:
AC_SYS_LARGEFILE
in effect.
off_t
is a 32-bit type, this function is not
applicable to arbitrary lengths for files 2 GiB and larger.
See Large File Support.
Portability problems not fixed by Gnulib:
truncf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/truncf.html
Gnulib module: truncf or truncf-ieee
Portability problems fixed by either Gnulib module truncf
or truncf-ieee
:
-D_GNU_SOURCE
) on some platforms:
glibc 2.8.
Portability problems fixed by Gnulib module truncf-ieee
:
Portability problems not fixed by Gnulib:
truncl
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/truncl.html
Gnulib module: truncl or truncl-ieee
Portability problems fixed by either Gnulib module truncl
or truncl-ieee
:
-D_GNU_SOURCE
) on some platforms:
glibc 2.8.
Portability problems fixed by Gnulib module truncl-ieee
:
Portability problems not fixed by Gnulib:
tsearch
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/tsearch.html
Gnulib module: tsearch
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
tss_create
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/ISO-C-Thread_002dlocal-Storage.html.
Gnulib module: tss
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
tss_delete
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/ISO-C-Thread_002dlocal-Storage.html.
Gnulib module: tss
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
tss_get
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/ISO-C-Thread_002dlocal-Storage.html.
Gnulib module: tss
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
tss_set
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/ISO-C-Thread_002dlocal-Storage.html.
Gnulib module: tss
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
ttyname
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ttyname.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
ttyname_r
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ttyname_r.html
Gnulib module: ttyname_r
Portability problems fixed by Gnulib:
_REENTRANT
is defined,
on some platforms:
HP-UX 11.
_POSIX_PTHREAD_SEMANTICS
is not defined).
Portability problems not fixed by Gnulib:
twalk
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/twalk.html
Gnulib module: tsearch
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
tzname
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/tzname.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
tzset
.
A more portable way of getting the time zone abbreviation is to use
strftime
with the %Z
format. See strftime
.
tzset
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/tzset.html
Gnulib module: tzset
Portability problems fixed by Gnulib:
TZ
has been set by Cygwin.
Portability problems not fixed by Gnulib:
TZ
environment variable,
consisting of a time zone abbreviation containing exactly three ASCII
letters with no daylight saving time or angle brackets, and with no
support for tz
database settings like
TZ='America/New_York'
. Even this subset does not work on
applications built via the Universal Windows Platform, as it does not
make environment variables like TZ
available to applications.
TZ
values,
as this feature was added in IEEE Std 1003.1-2001.
ufromfp
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/Rounding-Functions.html.
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
ufromfpf
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/Rounding-Functions.html.
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
ufromfpl
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/Rounding-Functions.html.
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
ufromfpx
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/Rounding-Functions.html.
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
ufromfpxf
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/Rounding-Functions.html.
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
ufromfpxl
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/Rounding-Functions.html.
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
ulimit
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ulimit.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getrlimit
and setrlimit
instead.
umask
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/umask.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
uname
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/uname.html
Gnulib module: uname
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
ungetc
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ungetc.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
errno
upon failure.
ungetwc
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ungetwc.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
unlink
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/unlink.html
LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-unlink-3.html
Gnulib module: unlink
Portability problems fixed by Gnulib:
<stdio.h>
)
on some platforms:
MSVC 14.
unlink("link-to-file/")
:
GNU/Hurd, FreeBSD 7.2, AIX 7.1, Solaris 9.
unlink("..")
succeeds
without doing anything.
Portability problems not fixed by Gnulib:
EPERM
. Meanwhile, if a process
has the ability to unlink directories, POSIX requires that
unlink("symlink-to-dir/")
remove dir and leave
symlink-to-dir dangling; this behavior is counter-intuitive.
The gnulib module unlinkdir
can help determine whether code must be
cautious of unlinking directories.
unlinkat
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/unlinkat.html
Gnulib module: unlinkat
Portability problems fixed by Gnulib:
<fcntl.h>
, not in <unistd.h>
,
on some platforms:
Cygwin 1.7.1, Android 4.3.
unlinkat(fd, "..", 0)
succeeds
without doing anything.
unlinkat(fd,"file/",flag)
:
GNU/Hurd, Solaris 9.
Portability problems not fixed by Gnulib:
unlinkat(fd,name,AT_REMOVEDIR)
fails because the specified
directory is not empty, the errno
value is system dependent.
unlinkdir(fd,"link-to-empty/",AT_REMOVEDIR)
remove empty and leave link-to-empty as a dangling
symlink. This is counter-intuitive, so some systems fail with
ENOTDIR
instead:
glibc
EPERM
. Meanwhile, if a process
has the ability to unlink directories, POSIX requires that
unlinkat(fd,"symlink-to-dir/",0)
remove dir and leave
symlink-to-dir dangling; this behavior is counter-intuitive.
The gnulib module unlinkdir
can help determine whether code must be
cautious of unlinking directories.
unlockpt
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/unlockpt.html
Gnulib module: unlockpt
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
unsetenv
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/unsetenv.html
Gnulib module: unsetenv
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
unsetenv(NULL)
gracefully
fail with EINVAL
, but not all implementations guarantee this,
and the requirement was removed.
uselocale
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/uselocale.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
setlocale
invocations on some platforms:
AIX 7.2.
locale_t
type is not defined
on some platforms:
z/OS.
locale_t
type contains basically
no information on some platforms:
OpenBSD 6.3.
utime
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/utime.html
Gnulib module: utime
Portability problems fixed by Gnulib:
TZ
is set).
utime
omits const
for the second argument:
mingw, MSVC 14.
utime("link-to-file/",buf)
succeeds instead
of failing with ENOTDIR
.
macOS 11.1.
Portability problems not fixed by Gnulib:
utimensat(AT_FDCWD,file,times,0)
, or the gnulib module utimens
,
instead.
utimens
instead.
utimensat
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/utimensat.html
Gnulib module: utimensat
Portability problems fixed by Gnulib:
ENOSYS
on some platforms:
Linux kernel 2.6.21.
ENOSYS
if passed the flag
AT_SYMLINK_NOFOLLOW
on a regular file:
Linux kernel 2.6.22.
UTIME_OMIT
or UTIME_NOW
, some systems require
the tv_sec
argument to be 0, and don’t necessarily handle all
file permissions in the manner required by POSIX:
Linux kernel 2.6.25.
UTIME_OMIT
for the modification time, but specifying
an access time, some systems fail to update the change time:
Linux kernel 2.6.32, macOS 11.1, NetBSD 9.0, Solaris 11.1.
tv_nsec
do not lead to a failure on some
platforms:
Linux kernel 2.6.22.19 on hppa.
Portability problems not fixed by Gnulib:
ENOSYS
if passed the flag
AT_SYMLINK_NOFOLLOW
on a symlink.
lstat
modifies the access time of
symlinks on some platforms, so utimensat
with
AT_SYMLINK_NOFOLLOW
can only effectively change modification time:
Cygwin.
stat
modifies the access time of
directories on some platforms, so utimensat
can only
effectively change directory modification time:
Cygwin 1.5.x.
The gnulib module fdutimensat
provides a similar interface.
utimes
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/utimes.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
utimensat(AT_FDCWD,file,times,0)
, or the gnulib module utimens
,
instead.
utimes (file, NULL)
fails to set the
file’s timestamp to the current time:
glibc 2.3.3.
utimes
failed on read-only files when
utime
worked fine.
glibc 2.2.5.
Extension: Gnulib provides a module ‘utimens’ that works around these problems and allows to set the time with nanosecond resolution (as far as supported by the file system).
va_arg
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/va_arg.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
va_arg
must be a type that is invariant under
the “default argument promotions” (ISO C 99 6.5.2.2 paragraph 6). This
means that the following are not valid here:
Use ‘double’ instead.
Use ‘int’ instead.
Use ‘int’ or ‘unsigned int’ instead.
This is a portability problem because you don’t know the width of some
abstract types like uid_t
, gid_t
, mode_t
. So, instead of
mode = va_arg (ap, mode_t);
you have to write
mode = (sizeof (mode_t) < sizeof (int) ? va_arg (ap, int) : va_arg (ap, mode_t));
va_copy
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/va_copy.html
Gnulib module: stdarg
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
va_end
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/va_end.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
va_start
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/va_start.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
vdprintf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/vdprintf.html
Gnulib module: vdprintf or vdprintf-posix or vdprintf-gnu
Portability problems fixed by either Gnulib module vdprintf
or vdprintf-posix
or vdprintf-gnu
:
Portability problems fixed by either Gnulib module vdprintf-posix
or vdprintf-gnu
:
w8
,
w16
, w32
, w64
, wf8
, wf16
, wf32
,
wf64
) on some platforms:
glibc, musl libc, macOS 12.5, FreeBSD 13.1, NetBSD 9.0, OpenBSD 7.2,
AIX 7.2, Solaris 11.4, Cygwin 2.9.0.
"%f"
, "%e"
, "%g"
of Infinity and NaN yields an
incorrect result on some platforms:
Solaris 11.4.
_FORTIFY_SOURCE >= 2
(set by default on Ubuntu),
Android, OpenBSD, macOS 11.1.
"%010f"
of NaN and Infinity yields an incorrect result (padded
with zeroes, or wrong capitalization) on some platforms:
Solaris 11.4.
"%#.0x"
or "%#.0X"
with a zero argument yields an
incorrect result (non-empty) on some platforms:
Mac OS X 10.6.
Portability problems fixed by Gnulib module vdprintf-gnu
:
Portability problems not fixed by Gnulib:
%m
directive is not portable, use %s
mapped to an
argument of strerror(errno)
(or a version of strerror_r
)
instead.
errno
or the
stream error indicator on attempts to write to a read-only stream:
Cygwin 1.7.9.
vfprintf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/vfprintf.html
Gnulib module: vfprintf-posix or vfprintf-gnu or stdio, nonblocking, sigpipe
Portability problems fixed by either Gnulib module vfprintf-posix
or vfprintf-gnu
:
hh
, ll
,
j
, t
, z
) on some platforms:
AIX 5.1, HP-UX 11.23, IRIX 6.5, Solaris 9, Cygwin 1.5.24, old mingw, MSVC 9.
w8
,
w16
, w32
, w64
, wf8
, wf16
, wf32
,
wf64
) on some platforms:
glibc, musl libc, macOS 12.5, FreeBSD 13.1, NetBSD 9.0, OpenBSD 7.2,
AIX 7.2, HP-UX 11, IRIX 6.5, Solaris 11.4, Cygwin 2.9.0, mingw, MSVC 14.
"%f"
, "%e"
, "%g"
of Infinity and NaN yields an
incorrect result on some platforms:
AIX 5.2, Solaris 11.4, mingw, MSVC 14.
_FORTIFY_SOURCE >= 2
(set by default on Ubuntu),
Android, OpenBSD, macOS 11.1, MSVC 14.
"%2$s"
, on some platforms:
NetBSD 3.0, mingw, MSVC 14.
'
flag on some platforms:
NetBSD 3.0, Cygwin 1.5.24, mingw, MSVC 14.
"%010f"
of NaN and Infinity yields an incorrect result (padded
with zeroes, or wrong capitalization) on some platforms:
Mac OS X 10.5, FreeBSD 6.0, NetBSD 5.0, AIX 5.2, IRIX 6.5, Solaris 11.4, Cygwin 1.5.x, mingw, MSVC/clang.
"%#.0x"
or "%#.0X"
with a zero argument yields an
incorrect result (non-empty) on some platforms:
Mac OS X 10.6.
Portability problems fixed by Gnulib module vfprintf-gnu
:
Portability problems fixed by Gnulib module stdio
or vfprintf-posix
or vfprintf-gnu
, together with module nonblocking
:
errno
being set to ENOSPC
instead of EAGAIN
on some
platforms:
mingw, MSVC 14.
Portability problems fixed by Gnulib module stdio
or vfprintf-posix
or vfprintf-gnu
, together with module sigpipe
:
SIGPIPE
handler, on some platforms:
mingw, MSVC 14.
Portability problems not fixed by Gnulib:
%m
directive is not portable, use %s
mapped to an
argument of strerror(errno)
(or a version of strerror_r
)
instead.
EOF
but
does not set the error flag for ferror
on some platforms:
glibc 2.13, cygwin 1.7.9.
vfscanf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/vfscanf.html
LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-vfscanf.html
Gnulib module: vfscanf, nonblocking
Portability problems fixed by Gnulib module vfscanf
, together with module nonblocking
:
errno
being set to EINVAL
instead of EAGAIN
on
some platforms:
mingw, MSVC 14.
Portability problems not fixed by Gnulib:
errno
upon failure.
hh
, ll
, j
,
t
, z
size specifiers.
vfwprintf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/vfwprintf.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
w8
,
w16
, w32
, w64
, wf8
, wf16
, wf32
,
wf64
) on some platforms:
glibc, musl libc, macOS 12.5, FreeBSD 13.1, NetBSD 9.0, OpenBSD 7.2,
AIX 7.2, HP-UX 11, Solaris 11.4, Cygwin 2.9.0, mingw, MSVC 14.
"%#.0x"
or "%#.0X"
with a zero argument yields an
incorrect result (non-empty) on some platforms:
Mac OS X 10.6.
%m
directive is not portable, use %s
mapped to an
argument of strerror(errno)
(or a version of strerror_r
)
instead.
%c
and %s
conversions may fail
on some platforms:
glibc 2.35.
errno
or the
stream error indicator on attempts to write to a read-only stream:
Cygwin 1.7.9.
vfwscanf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/vfwscanf.html
LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-vfwscanf.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
vprintf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/vprintf.html
Gnulib module: vprintf-posix or vprintf-gnu or stdio, nonblocking, sigpipe
Portability problems fixed by either Gnulib module vprintf-posix
or vprintf-gnu
:
hh
, ll
,
j
, t
, z
) on some platforms:
AIX 5.1, HP-UX 11.23, IRIX 6.5, Solaris 9, Cygwin 1.5.24, old mingw, MSVC 9.
w8
,
w16
, w32
, w64
, wf8
, wf16
, wf32
,
wf64
) on some platforms:
glibc, musl libc, macOS 12.5, FreeBSD 13.1, NetBSD 9.0, OpenBSD 7.2,
AIX 7.2, HP-UX 11, IRIX 6.5, Solaris 11.4, Cygwin 2.9.0, mingw, MSVC 14.
"%f"
, "%e"
, "%g"
of Infinity and NaN yields an
incorrect result on some platforms:
AIX 5.2, Solaris 11.4, mingw, MSVC 14.
_FORTIFY_SOURCE >= 2
(set by default on Ubuntu),
Android, OpenBSD, macOS 11.1, MSVC 14.
"%2$s"
, on some platforms:
NetBSD 3.0, mingw, MSVC 14.
'
flag on some platforms:
NetBSD 3.0, Cygwin 1.5.24, mingw, MSVC 14.
"%010f"
of NaN and Infinity yields an incorrect result (padded
with zeroes, or wrong capitalization) on some platforms:
Mac OS X 10.5, FreeBSD 6.0, NetBSD 5.0, AIX 5.2, IRIX 6.5, Solaris 11.4, Cygwin 1.5.x, mingw, MSVC/clang.
"%#.0x"
or "%#.0X"
with a zero argument yields an
incorrect result (non-empty) on some platforms:
Mac OS X 10.6.
Portability problems fixed by Gnulib module vprintf-gnu
:
Portability problems fixed by Gnulib module stdio
or vprintf-posix
or vprintf-gnu
, together with module nonblocking
:
errno
being set to ENOSPC
instead of EAGAIN
on some
platforms:
mingw, MSVC 14.
Portability problems fixed by Gnulib module stdio
or vprintf-posix
or vprintf-gnu
, together with module sigpipe
:
SIGPIPE
handler, on some platforms:
mingw, MSVC 14.
Portability problems not fixed by Gnulib:
%m
directive is not portable, use %s
mapped to an
argument of strerror(errno)
(or a version of strerror_r
)
instead.
EOF
but
does not set the error flag for ferror
on some platforms:
glibc 2.13, cygwin 1.7.9.
vscanf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/vscanf.html
LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-vscanf.html
Gnulib module: vscanf, nonblocking
Portability problems fixed by Gnulib module vscanf
, together with module nonblocking
:
errno
being set to EINVAL
instead of EAGAIN
on
some platforms:
mingw, MSVC 14.
Portability problems not fixed by Gnulib:
errno
upon failure.
hh
, ll
, j
,
t
, z
size specifiers.
vsnprintf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/vsnprintf.html
Gnulib module: vsnprintf or vsnprintf-posix or vsnprintf-gnu
Portability problems fixed by either Gnulib module vsnprintf
or vsnprintf-posix
or vsnprintf-gnu
:
"%2$s"
, on some platforms:
NetBSD 3.0, mingw, MSVC 14.
Portability problems fixed by either Gnulib module vsnprintf-posix
or vsnprintf-gnu
:
hh
, ll
,
j
, t
, z
) on some platforms:
AIX 5.1, HP-UX 11.23, IRIX 6.5, Solaris 9, Cygwin 1.5.24, old mingw, MSVC 9.
w8
,
w16
, w32
, w64
, wf8
, wf16
, wf32
,
wf64
) on some platforms:
glibc, musl libc, macOS 12.5, FreeBSD 13.1, NetBSD 9.0, OpenBSD 7.2,
AIX 7.2, HP-UX 11, IRIX 6.5, Solaris 11.4, Cygwin 2.9.0, mingw, MSVC 14.
"%f"
, "%e"
, "%g"
of Infinity and NaN yields an
incorrect result on some platforms:
AIX 5.2, Solaris 11.4, mingw, MSVC 14.
'
flag on some platforms:
NetBSD 3.0, Cygwin 1.5.24, mingw, MSVC 14.
"%010f"
of NaN and Infinity yields an incorrect result (padded
with zeroes, or wrong capitalization) on some platforms:
Mac OS X 10.5, FreeBSD 6.0, NetBSD 5.0, AIX 5.2, IRIX 6.5, Solaris 11.4, Cygwin 1.5.x, mingw, MSVC/clang.
"%#.0x"
or "%#.0X"
with a zero argument yields an
incorrect result (non-empty) on some platforms:
Mac OS X 10.6.
_FORTIFY_SOURCE >= 2
(set by default on Ubuntu),
Android, OpenBSD, macOS 11.1, HP-UX 11, mingw, MSVC 14.
Portability problems fixed by Gnulib module vsnprintf-gnu
:
Portability problems not fixed by Gnulib:
%m
directive is not portable, use %s
mapped to an
argument of strerror(errno)
(or a version of strerror_r
)
instead.
vsprintf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/vsprintf.html
Gnulib module: vsprintf-posix or vsprintf-gnu
Portability problems fixed by either Gnulib module vsprintf-posix
or vsprintf-gnu
:
hh
, ll
,
j
, t
, z
) on some platforms:
AIX 5.1, HP-UX 11.23, IRIX 6.5, Solaris 9, Cygwin 1.5.24, old mingw, MSVC 9.
w8
,
w16
, w32
, w64
, wf8
, wf16
, wf32
,
wf64
) on some platforms:
glibc, musl libc, macOS 12.5, FreeBSD 13.1, NetBSD 9.0, OpenBSD 7.2,
AIX 7.2, HP-UX 11, IRIX 6.5, Solaris 11.4, Cygwin 2.9.0, mingw, MSVC 14.
"%f"
, "%e"
, "%g"
of Infinity and NaN yields an
incorrect result on some platforms:
AIX 5.2, Solaris 11.4, mingw, MSVC 14.
_FORTIFY_SOURCE >= 2
(set by default on Ubuntu),
Android, OpenBSD, macOS 11.1, MSVC 14.
"%2$s"
, on some platforms:
NetBSD 3.0, mingw, MSVC 14.
'
flag on some platforms:
NetBSD 3.0, Cygwin 1.5.24, mingw, MSVC 14.
"%010f"
of NaN and Infinity yields an incorrect result (padded
with zeroes, or wrong capitalization) on some platforms:
Mac OS X 10.5, FreeBSD 6.0, NetBSD 5.0, AIX 5.2, IRIX 6.5, Solaris 11.4, Cygwin 1.5.x, mingw, MSVC/clang.
"%#.0x"
or "%#.0X"
with a zero argument yields an
incorrect result (non-empty) on some platforms:
Mac OS X 10.6.
Portability problems fixed by Gnulib module vsprintf-gnu
:
Portability problems not fixed by Gnulib:
%m
directive is not portable, use %s
mapped to an
argument of strerror(errno)
(or a version of strerror_r
)
instead.
vsscanf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/vsscanf.html
LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-vsscanf.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
errno
upon failure.
hh
, ll
, j
,
t
, z
size specifiers.
vswprintf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/vswprintf.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
w8
,
w16
, w32
, w64
, wf8
, wf16
, wf32
,
wf64
) on some platforms:
glibc, musl libc, macOS 12.5, FreeBSD 13.1, NetBSD 9.0, OpenBSD 7.2,
AIX 7.2, HP-UX 11, Solaris 11.4, Cygwin 2.9.0, mingw, MSVC 14.
"%#.0x"
or "%#.0X"
with a zero argument yields an
incorrect result (non-empty) on some platforms:
Mac OS X 10.6.
%m
directive is not portable, use %s
mapped to an
argument of strerror(errno)
(or a version of strerror_r
)
instead.
%c
and %s
conversions may fail
on some platforms:
glibc 2.35.
vswscanf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/vswscanf.html
LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-vswscanf.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
vwprintf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/vwprintf.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
w8
,
w16
, w32
, w64
, wf8
, wf16
, wf32
,
wf64
) on some platforms:
glibc, musl libc, macOS 12.5, FreeBSD 13.1, NetBSD 9.0, OpenBSD 7.2,
AIX 7.2, HP-UX 11, Solaris 11.4, Cygwin 2.9.0, mingw, MSVC 14.
"%#.0x"
or "%#.0X"
with a zero argument yields an
incorrect result (non-empty) on some platforms:
Mac OS X 10.6.
%m
directive is not portable, use %s
mapped to an
argument of strerror(errno)
(or a version of strerror_r
)
instead.
%c
and %s
conversions may fail
on some platforms:
glibc 2.35.
errno
or the
stream error indicator on attempts to write to a read-only stream:
Cygwin 1.7.9.
vwscanf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/vwscanf.html
LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-vwscanf.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
wait
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wait.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
waitid
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/waitid.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
waitid
with flag WNOWAIT
works correctly.
waitpid
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/waitpid.html
LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-waitpid-3.html
Gnulib module: waitpid
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wcpcpy
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wcpcpy.html
Gnulib module: wcpcpy
Portability problems fixed by Gnulib:
-D_GNU_SOURCE
) on some platforms:
glibc 2.13.
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
wcpncpy
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wcpncpy.html
Gnulib module: wcpncpy
Portability problems fixed by Gnulib:
-D_GNU_SOURCE
) on some platforms:
glibc 2.13.
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
wcrtomb
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wcrtomb.html
Gnulib module: wcrtomb
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and
therefore cannot accommodate all Unicode characters.
However, the ISO C11 function c32rtomb
, provided by Gnulib module
c32rtomb
, operates on 32-bit wide characters and therefore does not have
this limitation.
wcscasecmp
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wcscasecmp.html
Gnulib module: wcscasecmp
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
wcscasecmp_l
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wcscasecmp_l.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
wcscat
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wcscat.html
Gnulib module: wcscat
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
wcschr
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wcschr.html
Gnulib module: wcschr
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
wcscmp
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wcscmp.html
Gnulib module: wcscmp
Portability problems fixed by Gnulib:
wchar_t
is signed, on some platforms:
glibc 2.14.1 on x86 or x86_64, musl libc 1.2.3, macOS 12.5,
FreeBSD 13.2,
NetBSD 9.0, OpenBSD 7.2, Solaris 11.4.
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
wcscoll
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wcscoll.html
Gnulib module: wcscoll
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
wcscoll_l
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wcscoll_l.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
wcscpy
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wcscpy.html
Gnulib module: wcscpy
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
Note: wcscpy (dst, src)
is only safe to use when you can guarantee that
there are at least wcslen (src) + 1
wide characters allocated at
dst
.
wcscspn
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wcscspn.html
Gnulib module: wcscspn
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
wcsdup
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wcsdup.html
Gnulib module: wcsdup
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
wcsftime
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wcsftime.html
Gnulib module: wcsftime
Portability problems fixed by Gnulib:
TZ
has been set by Cygwin.
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
tzset
.
wcslen
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wcslen.html
Gnulib module: wcslen
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
wcsncasecmp
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wcsncasecmp.html
Gnulib module: wcsncasecmp
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
wcsncasecmp_l
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wcsncasecmp_l.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
wcsncat
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wcsncat.html
Gnulib module: wcsncat
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
wcsncmp
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wcsncmp.html
Gnulib module: wcsncmp
Portability problems fixed by Gnulib:
wchar_t
is signed, on some platforms:
glibc 2.14.1 on x86 or x86_64, musl libc 1.2.3, macOS 12.5,
FreeBSD 13.2,
NetBSD 9.0, OpenBSD 7.2, Solaris 11.4.
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
wcsncpy
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wcsncpy.html
Gnulib module: wcsncpy
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore
cannot accommodate all Unicode characters.
Note: This function has no real use: It cannot be used for filling a fixed-size record with a wide string, before writing it to a file, because the wide string encoding is platform dependent and, on some platforms, also locale dependent. And this function is not appropriate for copying a wide string into a bounded memory area, because you have no guarantee that the result will be null-terminated. Even if you add the null character at the end yourself, this function is inefficient (as it spends time clearing unused memory) and will allow silent truncation to occur, which is not a good behavior for GNU programs.
wcsnlen
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wcsnlen.html
Gnulib module: wcsnlen
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
wcsnrtombs
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wcsnrtombs.html
Gnulib module: wcsnrtombs
Portability problems fixed by Gnulib:
<wchar.h>
defines std::wcsnrtombs
but
not ::wcsnrtombs
on some platforms:
Solaris 11 OpenIndiana.
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and
therefore cannot accommodate all Unicode characters.
However, the Gnulib function c32snrtombs
, provided by Gnulib module
c32snrtombs
, operates on 32-bit wide characters and therefore does not
have this limitation.
wcspbrk
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wcspbrk.html
Gnulib module: wcspbrk
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
wcsrchr
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wcsrchr.html
Gnulib module: wcsrchr
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
wcsrtombs
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wcsrtombs.html
Gnulib module: wcsrtombs
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and
therefore cannot accommodate all Unicode characters.
However, the Gnulib function c32srtombs
, provided by Gnulib module
c32srtombs
, operates on 32-bit wide characters and therefore does not
have this limitation.
wcsspn
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wcsspn.html
Gnulib module: wcsspn
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
wcsstr
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wcsstr.html
Gnulib module: wcsstr or wcsstr-simple
Portability problems fixed by either Gnulib module wcsstr-simple
or wcsstr
:
Portability problems fixed by Gnulib module wcsstr
:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
wcstod
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wcstod.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
wcstof
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wcstof.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
wcstoimax
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wcstoimax.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
wcstok
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wcstok.html
Gnulib module: wcstok
Portability problems fixed by Gnulib:
wcstok
iteration loops are being performed
in the same thread, on some platforms:
HP-UX 11.31.
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
wcstol
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wcstol.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
wcstold
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wcstold.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
wcstoll
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wcstoll.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
wcstombs
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wcstombs.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and
therefore cannot accommodate all Unicode characters.
However, the Gnulib function c32stombs
, provided by Gnulib module
c32stombs
, operates on 32-bit wide characters and therefore does not
have this limitation.
wcstoul
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wcstoul.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
wcstoull
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wcstoull.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
wcstoumax
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wcstoumax.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
wcswidth
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wcswidth.html
Gnulib module: wcswidth
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
However, the Gnulib function c32swidth
, provided by Gnulib module
c32swidth
, operates on 32-bit wide characters and therefore does not
have this limitation.
wcsxfrm
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wcsxfrm.html
Gnulib module: wcsxfrm
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
wcsxfrm_l
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wcsxfrm_l.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
wctob
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wctob.html
Gnulib module: wctob
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and
therefore cannot accommodate all Unicode characters.
However, the Gnulib function c32tob
, provided by Gnulib module
c32tob
, operates on 32-bit wide characters and therefore does not have
this limitation.
wctomb
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wctomb.html
Gnulib module: wctomb
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
wctrans
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wctrans.html
Gnulib module: wctrans
Portability problems fixed by Gnulib:
"tolower"
and "toupper"
mappings on some platforms:
NetBSD 9.3.
(It returns non-null values for the arguments "towlower"
and
"towupper"
, but with these values, the function towctrans
always crashes.)
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
However, the Gnulib function c32_get_mapping
, provided by Gnulib module
c32_get_mapping
, operates on 32-bit wide characters and therefore does
not have this limitation.
wctrans_l
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wctrans_l.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
wctype
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wctype.html
Gnulib module: wctype
Portability problems fixed by Gnulib:
<wchar.h>
, not in <wctype.h>
, on
some platforms:
HP-UX 11.00.
"blank"
character class
on some platforms:
mingw.
"blank"
character class
is inconsistent with the iswblank
and isblank
functions
on some platforms:
MSVC 14.
"punct"
character class
is inconsistent with the ispunct
function on some platforms:
Android 11.
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
However, the Gnulib function c32_get_type_test
, provided by Gnulib
module c32_get_type_test
, operates on 32-bit wide characters and
therefore does not have this limitation.
wctype_l
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wctype_l.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
wcwidth
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wcwidth.html
Gnulib module: wcwidth
Portability problems fixed by Gnulib:
-D_GNU_SOURCE
) on some platforms:
glibc 2.8.
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
However, the Gnulib function c32width
, provided by Gnulib module
c32width
, operates on 32-bit wide characters and therefore does not
have this limitation.
wmemchr
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wmemchr.html
Gnulib module: wmemchr
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
wmemcmp
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wmemcmp.html
Gnulib module: wmemcmp
Portability problems fixed by Gnulib:
wchar_t
is signed, on some platforms:
glibc 2.14.1 on x86 or x86_64, musl libc 1.2.3, NetBSD 9.0, OpenBSD 7.2, Solaris 11.4.
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
wmemcpy
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wmemcpy.html
Gnulib module: wmemcpy
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
wmemmove
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wmemmove.html
Gnulib module: wmemmove
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
wmemset
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wmemset.html
Gnulib module: wmemset
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
wordexp
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wordexp.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
errno
or the
stream error indicator on attempts to write to a read-only stream:
Cygwin 1.7.9.
wordfree
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wordfree.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wprintf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wprintf.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
w8
,
w16
, w32
, w64
, wf8
, wf16
, wf32
,
wf64
) on some platforms:
glibc, musl libc, macOS 12.5, FreeBSD 13.1, NetBSD 9.0, OpenBSD 7.2,
AIX 7.2, HP-UX 11, Solaris 11.4, Cygwin 2.9.0, mingw, MSVC 14.
"%#.0x"
or "%#.0X"
with a zero argument yields an
incorrect result (non-empty) on some platforms:
Mac OS X 10.6.
%m
directive is not portable, use %s
mapped to an
argument of strerror(errno)
(or a version of strerror_r
)
instead.
%c
and %s
conversions may fail
on some platforms:
glibc 2.35.
errno
or the
stream error indicator on attempts to write to a read-only stream:
Cygwin 1.7.9.
write
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/write.html
Gnulib module: write, nonblocking, sigpipe
Portability problems fixed by Gnulib module write
:
<io.h>
)
on some platforms:
mingw, MSVC 14.
Portability problems fixed by Gnulib module stdio
, together with module nonblocking
:
errno
being set to ENOSPC
instead of EAGAIN
on some
platforms:
mingw, MSVC 14.
Portability problems fixed by Gnulib module stdio
, together with module sigpipe
:
EINVAL
, instead of obeying the current SIGPIPE
handler, on
some platforms:
mingw, MSVC 14.
Portability problems not fixed by Gnulib:
EINTR
, even in programs that don’t
install any signal handlers, on some platforms:
macOS 11.1.
For handling EINTR
, Gnulib provides a module ‘safe-write’ with a
function safe_write
.
writev
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/writev.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wscanf
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wscanf.html
LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-wscanf.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
y0
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/y0.html
Gnulib module: y0
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
y1
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/y1.html
Gnulib module: y1
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
yn
¶POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/yn.html
Gnulib module: yn
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
This chapter describes which functions and function-like macros specified by older versions of POSIX are substituted by Gnulib, which portability pitfalls are fixed by Gnulib, and which (known) portability problems are not worked around by Gnulib.
The notation “Gnulib module: —” means that Gnulib does not provide a
module providing a substitute for the function. When the list
“Portability problems not fixed by Gnulib” is empty, such a module is
not needed: No portability problems are known. Otherwise, it indicates
that such a module would be useful but is not available: No one so far
found this function important enough to contribute a substitute for it.
If you need this particular function, you may write to
<bug-gnulib at gnu dot org>
.
bcmp
bcopy
bsd_signal
bzero
ecvt
fcvt
ftime
gcvt
getcontext
gethostbyaddr
gethostbyname
getwd
h_errno
index
makecontext
mktemp
pthread_attr_getstackaddr
pthread_attr_setstackaddr
rindex
scalb
setcontext
swapcontext
ualarm
usleep
vfork
wcswcs
bcmp
¶POSIX specification: https://pubs.opengroup.org/onlinepubs/009695399/functions/bcmp.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
memcmp
instead.
bcopy
¶POSIX specification: https://pubs.opengroup.org/onlinepubs/009695399/functions/bcopy.html
Gnulib module: bcopy
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
memcpy
or memmove
instead.
bsd_signal
¶POSIX specification: https://pubs.opengroup.org/onlinepubs/009695399/functions/bsd_signal.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
bzero
¶POSIX specification: https://pubs.opengroup.org/onlinepubs/009695399/functions/bzero.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
memset
instead.
ecvt
¶POSIX specification: https://pubs.opengroup.org/onlinepubs/009695399/functions/ecvt.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
sprintf
instead.
fcvt
¶POSIX specification: https://pubs.opengroup.org/onlinepubs/009695399/functions/fcvt.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
sprintf
instead.
ftime
¶POSIX specification: https://pubs.opengroup.org/onlinepubs/009695399/functions/ftime.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
TZ
has been set by Cygwin.
gettimeofday
or clock_gettime
instead, and use ftime
only as a fallback for
portability to Windows platforms.
gcvt
¶POSIX specification: https://pubs.opengroup.org/onlinepubs/009695399/functions/gcvt.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
sprintf
instead.
getcontext
¶POSIX specification: https://pubs.opengroup.org/onlinepubs/009695399/functions/getcontext.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
Note: A third-party implementation is available at https://github.com/kaniini/libucontext/.
gethostbyaddr
¶POSIX specification: https://pubs.opengroup.org/onlinepubs/009695399/functions/gethostbyaddr.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
gethostbyname
¶POSIX specification: https://pubs.opengroup.org/onlinepubs/009695399/functions/gethostbyname.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getwd
¶POSIX specification: https://pubs.opengroup.org/onlinepubs/009695399/functions/getwd.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getcwd
function instead.
h_errno
¶POSIX specification: https://pubs.opengroup.org/onlinepubs/009695399/functions/h_errno.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
index
¶POSIX specification: https://pubs.opengroup.org/onlinepubs/009695399/functions/index.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
strchr
instead.
makecontext
¶POSIX specification: https://pubs.opengroup.org/onlinepubs/009695399/functions/makecontext.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
Note: A third-party implementation is available at https://github.com/kaniini/libucontext/.
mktemp
¶POSIX specification: https://pubs.opengroup.org/onlinepubs/009695399/functions/mktemp.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
mkstemp
instead.
pthread_attr_getstackaddr
¶POSIX specification: https://pubs.opengroup.org/onlinepubs/009695399/functions/pthread_attr_getstackaddr.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_attr_setstackaddr
¶POSIX specification: https://pubs.opengroup.org/onlinepubs/009695399/functions/pthread_attr_setstackaddr.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
rindex
¶POSIX specification: https://pubs.opengroup.org/onlinepubs/009695399/functions/rindex.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
strrchr
instead.
scalb
¶POSIX specification: https://pubs.opengroup.org/onlinepubs/009695399/functions/scalb.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
setcontext
¶POSIX specification: https://pubs.opengroup.org/onlinepubs/009695399/functions/setcontext.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
Note: A third-party implementation is available at https://github.com/kaniini/libucontext/.
swapcontext
¶POSIX specification: https://pubs.opengroup.org/onlinepubs/009695399/functions/swapcontext.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
Note: A third-party implementation is available at https://github.com/kaniini/libucontext/.
ualarm
¶POSIX specification: https://pubs.opengroup.org/onlinepubs/009695399/functions/ualarm.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
usleep
¶POSIX specification: https://pubs.opengroup.org/onlinepubs/009695399/functions/usleep.html
Gnulib module: usleep
Portability problems fixed by Gnulib:
usleep
rejects attempts to sleep longer than 1
second, as allowed by POSIX:
NetBSD 9.0, mingw.
Portability problems not fixed by Gnulib:
usleep
function may interfere with the program’s
use of the SIGALRM
signal. On Linux, it doesn’t; on other platforms,
it may.
vfork
¶POSIX specification: https://pubs.opengroup.org/onlinepubs/009695399/functions/vfork.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wcswcs
¶POSIX specification: https://pubs.opengroup.org/onlinepubs/009695399/functions/wcswcs.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
wcsstr
instead.
This chapter describes which header files contained in GNU libc but not specified by ISO C or POSIX are substituted by Gnulib, which portability pitfalls are fixed by Gnulib, and which (known) portability problems are not worked around by Gnulib.
The notation “Gnulib module: —” means that Gnulib does not provide a
module providing a substitute for the header file. When the list
“Portability problems not fixed by Gnulib” is empty, such a module is
not needed: No portability problems are known. Otherwise, it indicates
that such a module would be useful but is not available: No one so far
found this header file important enough to contribute a substitute for it.
If you need this particular header file, you may write to
<bug-gnulib at gnu dot org>
.
Describes the structure of executables (and object files?) in the old
a.out
format.
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
Defines the type struct aliasent
and declares the functions
setaliasent
, endaliasent
,
getaliasent
, getaliasent_r
,
getaliasbyname
, getaliasbyname_r
.
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
Declares the alloca
function of function-like macro.
Documentation:
Gnulib module: alloca
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
Describes the structure of files produced by the ‘ar’ program.
Defines the type struct ar_hdr
and the macros ARMAG
,
SARMAG
, ARFMAG
.
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
Documentation:
Gnulib module: argp
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
Documentation:
Gnulib module: argz
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
Defines the functions or function-like macros bswap_16
, bswap_32
,
bswap_64
.
Gnulib module: byteswap
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
Defines the type struct crypt_data
and declares the functions
crypt
, crypt_r
,
setkey
, setkey_r
,
encrypt
, encrypt_r
.
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
crypt
, setkey
, encrypt
are missing on some
platforms:
HP-UX 11.
struct crypt_data
and the functions crypt_r
,
setkey_r
, encrypt_r
are missing on some platforms:
IRIX 6.5, Solaris 11.4, Cygwin.
Describe’s the platform’s endianness (byte ordering of words stored in memory).
Defines the macros BYTE_ORDER
, LITTLE_ENDIAN
, BIG_ENDIAN
,
PDP_ENDIAN
.
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
Declares the functions
warn
, vwarn
, warnx
, vwarnx
,
err
, verr
, errx
, verrx
.
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
Declares the functions error
, error_at_line
and the variables
error_print_progname
, error_message_count
,
error_one_per_line
.
Documentation:
Gnulib module: error-h
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
Declares the functions backtrace
, backtrace_symbols
,
backtrace_symbols_fd
.
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
Handling of the FPU control word. Defines the fpu_control_t
type,
declares the __fpu_control
variable, and defines the _FPU_GETCW
,
_FPU_SETCW
macros.
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
Defines the type struct fstab
, the macros FSTAB_*
,
_PATH_FSTAB
, and declares the functions
setfsent
, endfsent
,
getfsent
, getfsspec
, getfsfile
.
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
_PATH_FSTAB
is missing on some platforms:
AIX 5.1, HP-UX 11.
Defines the types FTS
, FTSENT
and the macros FTS_*
,
and declares the functions fts_open
, fts_read
,
fts_children
, fts_set
, fts_close
.
Documentation:
Gnulib module: fts
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
Defines the type struct option
and declares the variables
optarg
, optind
, opterr
, optopt
and the functions getopt
, getopt_long
, getopt_long_only
.
Documentation:
Gnulib module: getopt-gnu
Portability problems fixed by Gnulib:
getopt_long
is missing on some platforms:
IRIX 6.5, Solaris 9.
getopt_long_only
is missing on some platforms:
FreeBSD 5.2.1, NetBSD 9.0, IRIX 6.5, Solaris 9, mingw.
getopt
does not handle a leading ‘+’ character in
the options string on some platforms:
Solaris 11 2010-11.
Portability problems not fixed by Gnulib:
Defines the type struct sgrp
and declares the functions
setsgent
, endsgent
, getsgent
, getsgnam
,
sgetsgent
, fgetsgent
, putsgent
,
getsgent_r
, getsgnam_r
, sgetsgent_r
, fgetsgent_r
.
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
Defines the types union ieee754_float
, union ieee754_double
,
union ieee854_long_double
.
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
long
double
and does not work on some platforms.
Defines the type struct ifaddrs
and declares the functions
getifaddrs
, freeifaddrs
.
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
Defines the macros __USE_GNU_GETTEXT
,
__GNU_GETTEXT_SUPPORTED_REVISION
, and declares the functions
gettext
, dgettext
, dcgettext
,
ngettext
, dngettext
, dcngettext
,
textdomain
, bindtextdomain
, bind_textdomain_codeset
.
Documentation:
Gnulib module: gettext
Portability problems fixed by Gnulib, if GNU gettext is installed:
Portability problems not fixed by Gnulib:
Defines the type struct dl_phdr_info
, and declares the function
dl_iterate_phdr
.
Documentation: —
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
Declares the function memalign
and functions for customizing the
malloc
behavior.
Documentation:
Gnulib module: malloc-h
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
Defines the type enum mcheck_status
and declares the functions
mcheck
, mcheck_pedantic
, mcheck_check_all
, mprobe
,
mtrace
, muntrace
.
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
Defines the type struct mntent
and the macros MNTTAB
,
MOUNTED
, MNTTYPE_*
, MNTOPT_*
, and declares the functions
setmntent
, getmntent
, getmntent_r
, addmntent
,
endmntent
, hasmntopt
.
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getmntent_r
is missing on all non-glibc platforms:
AIX 5.1, HP-UX 11, IRIX 6.5, Cygwin, Android 9.0.
Gnulib module mountlist
provides a higher-level abstraction.
Documentation:
Gnulib module: obstack
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
Defines the macros _PATH_*
.
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
_PATH_*
macros is platform dependent.
Defines the type struct printf_info
and the macros and enum values
PA_*
, and declares the functions
printf_function
, printf_arginfo_function
,
register_printf_function
, parse_printf_format
,
printf_size
, printf_size_info
.
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
Declares the functions openpty
and forkpty
.
Documentation:
Gnulib module: pty
Portability problems fixed by Gnulib:
forkpty
and openpty
functions in util.h
or
libutil.h
instead:
macOS 11.1, FreeBSD 13.0, NetBSD 9.0, OpenBSD 6.7.
Portability problems not fixed by Gnulib:
Defines the types res_sendhookact
, res_send_qhook
,
res_send_rhook
, res_state
, struct res_sym
and the
macros _PATH_RESCONF
, RES_*
, and declares the functions
res_close
, res_init
,
res_mkquery
, res_query
, res_querydomain
,
res_search
, res_send
.
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
Defines the type struct spwd
and declares the functions
setspent
, endspent
,
getspent
, getspent_r
,
getspnam
, getspnam_r
,
sgetspent
, sgetspent_r
,
fgetspent
, fgetspent_r
,
putspent
,
lckpwdf
, ulckpwdf
.
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getspent_r
, getspnam_r
, sgetspent_r
,
fgetspent
, fgetspent_r
, putspent
are missing on some
platforms:
HP-UX 11.
sgetspent
, sgetspent_r
are missing on some
platforms:
HP-UX 11, IRIX 6.5, Solaris 11.4.
Declares the function flock
.
Gnulib module: sys_file
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
flock
function on some platforms:
AIX 7.1, HP-UX 11.23, Solaris 11.4.
Declares the function ioctl
.
Documentation:
Gnulib module: sys_ioctl
Portability problems fixed by Gnulib:
ioctl
function on some platforms:
AIX 5.1, Solaris 11.4, Haiku 2017.
Portability problems not fixed by Gnulib:
Declares the function getrandom
and the flags for it.
Documentation:
Gnulib module: sys_random
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
Defines the EX_*
macros, including EX_OK
.
Gnulib module: sysexits
Portability problems fixed by Gnulib:
EX_*
macros if _BSD_SOURCE
is not
defined on some platforms:
Haiku.
EX_CONFIG
is missing on some platforms:
HP-UX 11.
Portability problems not fixed by Gnulib:
Defines the type struct ttyent
and declares the functions
setttyent
, endttyent
, getttyent
, getttynam
.
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
Defines functions for login and logout (to a tty session) and for examining the history of logins and logouts.
Documentation:
Gnulib module: utmp
Portability problems fixed by Gnulib:
<sys/types.h>
is a prerequisite of <utmp.h>
on some platforms:
FreeBSD 8.0, OpenBSD 7.2.
Portability problems not fixed by Gnulib:
struct utmp
field ut_user
,
older platforms have the field ut_name
.
struct utmp
fields ut_id
, ut_pid
, ut_type
do not exist on some platforms:
macOS, old FreeBSD, NetBSD, OpenBSD, Minix.
struct utmp
field ut_host
does not exist on some platforms:
IRIX, Solaris.
struct utmp
field ut_exit
does not exist on some platforms:
macOS, old FreeBSD, NetBSD, OpenBSD, Minix, Cygwin.
struct utmp
field ut_session
does not exist on some platforms:
macOS, old FreeBSD, NetBSD, OpenBSD, Minix, AIX, HP-UX, IRIX, Solaris, Cygwin.
struct utmp
field ut_addr
or ut_addr_v6
does not exist
on some platforms:
macOS, old FreeBSD, NetBSD, OpenBSD, Minix, AIX, IRIX, Solaris.
time_t
was historically 32 bits.
year2038
or
year2038-recommended
modules are used and the program is
configured without the --disable-year2038 option.
The readutmp
module works around this problem:
glibc 2.38 on 32-bit platforms like x86 and ARM where time_t
was historically 32 bits.
See Avoiding the year 2038 problem.
This chapter describes which functions and function-like macros provided as extensions by at least GNU libc are also supported by Gnulib, which portability pitfalls are fixed by Gnulib, and which (known) portability problems are not worked around by Gnulib.
The notation “Gnulib module: —” means that Gnulib does not provide a
module providing a substitute for the function. When the list
“Portability problems not fixed by Gnulib” is empty, such a module is
not needed: No portability problems are known. Otherwise, it indicates
that such a module would be useful but is not available: No one so far
found this function important enough to contribute a substitute for it.
If you need this particular function, you may write to
<bug-gnulib at gnu dot org>
.
This list of functions is sorted according to the header that declares them.
<aio.h>
<aliases.h>
<argp.h>
<argz.h>
<arpa/inet.h>
<byteswap.h>
<complex.h>
<ctype.h>
<dirent.h>
<dlfcn.h>
<envz.h>
<err.h>
<errno.h>
<error.h>
<execinfo.h>
<fcntl.h>
<fenv.h>
<fmtmsg.h>
<fstab.h>
<fts.h>
<getopt.h>
<glob.h>
<gnu/libc-version.h>
<grp.h>
<gshadow.h>
<ifaddrs.h>
<libintl.h>
<link.h>
<malloc.h>
<math.h>
<mcheck.h>
<mntent.h>
<netdb.h>
<netinet/ether.h>
<netinet/in.h>
<obstack.h>
<poll.h>
<printf.h>
<pthread.h>
<pty.h>
<pwd.h>
<regex.h>
<regexp.h>
<resolv.h>
<rpc/auth.h>
<rpc/auth_des.h>
<rpc/auth_unix.h>
<rpc/clnt.h>
<rpc/key_prot.h>
<rpc/netdb.h>
<rpc/pmap_clnt.h>
<rpc/pmap_prot.h>
<rpc/pmap_rmt.h>
<rpc/rpc_msg.h>
<rpc/svc.h>
<rpc/xdr.h>
<rpcsvc/nislib.h>
<rpcsvc/nis_callback.h>
<rpcsvc/yp.h>
<rpcsvc/ypclnt.h>
<sched.h>
<search.h>
<selinux/selinux.h>
<semaphore.h>
<shadow.h>
<signal.h>
<spawn.h>
<stdio.h>
<stdlib.h>
<string.h>
<sys/auxv.h>
<sys/capability.h>
<sys/epoll.h>
<sys/eventfd.h>
<sys/fanotify.h>
<sys/file.h>
<sys/fsuid.h>
<sys/gmon.h>
<sys/inotify.h>
<sys/io.h>
, <sys/perm.h>
<sys/kdaemon.h>
<sys/klog.h>
<sys/mman.h>
<sys/mount.h>
<sys/personality.h>
<sys/prctl.h>
<sys/profil.h>
<sys/ptrace.h>
<sys/quota.h>
<sys/random.h>
<sys/reboot.h>
<sys/resource.h>
<sys/sem.h>
<sys/sendfile.h>
<sys/signalfd.h>
<sys/single_threaded.h>
<sys/socket.h>
<sys/stat.h>
<sys/statfs.h>
<sys/swap.h>
<sys/sysctl.h>
<sys/sysinfo.h>
<sys/syslog.h>
<sys/sysmacros.h>
<sys/time.h>
<sys/timerfd.h>
<sys/timex.h>
<sys/uio.h>
<sys/ustat.h>
<sys/vlimit.h>
<sys/wait.h>
<sys/xattr.h>
<termios.h>
<time.h>
<ttyent.h>
<unistd.h>
<utmp.h>
<utmpx.h>
<wchar.h>
<aio.h>
¶aio_init
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<aliases.h>
¶endaliasent
¶Documentation:
man endaliasent
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getaliasbyname
¶Documentation:
man getaliasbyname
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getaliasbyname_r
¶Documentation:
man getaliasbyname_r
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getaliasent
¶Documentation:
man getaliasent
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getaliasent_r
¶Documentation:
man getaliasent_r
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
setaliasent
¶Documentation:
man setaliasent
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<argp.h>
¶argp_err_exit_status
argp_error
argp_failure
argp_help
argp_parse
argp_program_bug_address
argp_program_version
argp_program_version_hook
argp_state_help
argp_usage
argp_err_exit_status
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/Argp-Global-Variables.html.
Gnulib module: argp
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
argp_error
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/Argp-Helper-Functions.html.
Gnulib module: argp
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
argp_failure
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/Argp-Helper-Functions.html.
Gnulib module: argp
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
argp_help
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/Argp-Help.html.
Gnulib module: argp
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
argp_parse
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/Argp.html.
Gnulib module: argp
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
argp_program_bug_address
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/Argp-Global-Variables.html.
Gnulib module: argp
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
argp_program_version
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/Argp-Global-Variables.html.
Gnulib module: argp
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
argp_program_version_hook
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/Argp-Global-Variables.html.
Gnulib module: argp
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
argp_state_help
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/Argp-Helper-Functions.html.
Gnulib module: argp
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
argp_usage
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/Argp-Helper-Functions.html.
Gnulib module: argp
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<argz.h>
¶argz_add
argz_add_sep
argz_append
argz_count
argz_create
argz_create_sep
argz_delete
argz_extract
argz_insert
argz_next
argz_replace
argz_stringify
argz_add
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-argz-add.html
Documentation:
Gnulib module: argz
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
argz_add_sep
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-argz-add.html
Documentation:
Gnulib module: argz
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
argz_append
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-argz-add.html
Documentation:
Gnulib module: argz
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
argz_count
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-argz-add.html
Documentation:
Gnulib module: argz
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
argz_create
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-argz-add.html
Documentation:
Gnulib module: argz
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
argz_create_sep
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-argz-add.html
Documentation:
Gnulib module: argz
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
argz_delete
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-argz-add.html
Documentation:
Gnulib module: argz
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
argz_extract
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-argz-add.html
Documentation:
Gnulib module: argz
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
argz_insert
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-argz-add.html
Documentation:
Gnulib module: argz
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
argz_next
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-argz-add.html
Documentation:
Gnulib module: argz
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
argz_replace
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-argz-add.html
Documentation:
Gnulib module: argz
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
argz_stringify
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-argz-add.html
Documentation:
Gnulib module: argz
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<arpa/inet.h>
¶inet_aton
inet_lnaof
inet_makeaddr
inet_net_ntop
inet_net_pton
inet_netof
inet_network
inet_nsap_addr
inet_nsap_ntoa
inet_aton
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-inet-aton-3.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
inet_lnaof
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
inet_makeaddr
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
inet_net_ntop
¶Documentation:
man inet_net_ntop
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
inet_net_pton
¶Documentation:
man inet_net_pton
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
inet_netof
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
inet_network
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
inet_nsap_addr
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
inet_nsap_ntoa
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<byteswap.h>
¶bswap_16
¶Documentation:
man bswap_16
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
bswap_32
¶Documentation:
man bswap_32
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
bswap_64
¶Documentation:
man bswap_64
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<complex.h>
¶clog10
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib---clog10.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
clog10f
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib---clog10f.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
clog10l
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib---clog10l.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<ctype.h>
¶isctype
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<dirent.h>
¶getdirentries
¶Documentation:
man getdirentries
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
off_t
is a 32-bit type, this function may not
work correctly on huge directories larger than 2 GB. The fix is to use
the AC_SYS_LARGEFILE
macro.
scandirat
¶Documentation:
man scandirat
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
versionsort
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<dlfcn.h>
¶dladdr
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-dladdr-3.html
Documentation:
man dladdr
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
dladdr1
¶Documentation:
man dladdr1
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
dlinfo
¶Documentation:
man dlinfo
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
dlmopen
¶Documentation:
man dlmopen
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
dlvsym
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-dlvsym-1.html
Documentation:
man dlvsym
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<envz.h>
¶envz_add
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-envz-add.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
envz_entry
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-envz-add.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
envz_get
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-envz-add.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
envz_merge
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-envz-add.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
envz_remove
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-envz-add.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
envz_strip
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-envz-add.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<err.h>
¶err
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-err-3.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
errx
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-errx-3.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
verr
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
verrx
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-verrx-3.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
vwarn
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
vwarnx
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
warn
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-warn-3.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
warnx
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-warnx-3.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<errno.h>
¶program_invocation_name
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
program_invocation_short_name
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<error.h>
¶error
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-error-n.html
Documentation:
Gnulib module: error
Portability problems fixed by Gnulib:
error_print_progname
is set,
on some platforms:
Android 11.
Portability problems not fixed by Gnulib:
error_at_line
¶Documentation:
Gnulib module: error
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
error_message_count
¶Documentation:
Gnulib module: error
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
error_one_per_line
¶Documentation:
Gnulib module: error
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
error_print_progname
¶Documentation:
man error_print_progname
Gnulib module: error
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<execinfo.h>
¶backtrace
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-backtrace-1.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
backtrace_symbols
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-backtrace-1.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
backtrace_symbols_fd
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-backtrace-1.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<fcntl.h>
¶fallocate
¶Documentation:
man fallocate
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
off_t
is a 32-bit type, this function may not
work correctly across the entire data range of files larger than 2 GB.
The fix is to use the AC_SYS_LARGEFILE
macro.
name_to_handle_at
¶Documentation:
man name_to_handle_at
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
readahead
¶Documentation:
man readahead
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
open_by_handle_at
¶Documentation:
man open_by_handle_at
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
sync_file_range
¶Documentation:
man sync_file_range
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<fenv.h>
¶fedisableexcept
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-fedisableexcept.html
Documentation:
Gnulib module: fenv-exceptions-trapping
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
feenableexcept
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-feenableexcept.html
Documentation:
Gnulib module: fenv-exceptions-trapping
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
SIGILL
instead of SIGFPE
on some platforms:
Linux/hppa, macOS 12.5/arm64.
fegetexcept
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-fegetexcept.html
Documentation:
Gnulib module: fenv-exceptions-trapping
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<fmtmsg.h>
¶addseverity
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<fstab.h>
¶endfsent
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getfsent
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getfsfile
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getfsspec
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
setfsent
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<fts.h>
¶fts_children
¶Documentation:
man fts_children
Gnulib module: fts
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
off_t
is a 32-bit type, this function may not
correctly report the size of files or block devices larger than 2 GB and
may not work correctly on huge directories larger than 2 GB. Also, on
platforms where ino_t
is a 32-bit type, this function may report
inode numbers incorrectly. The fix is to use the AC_SYS_LARGEFILE
macro (only on Mac OS X systems).
fts_close
¶Documentation:
man fts_close
Gnulib module: fts
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
fts_open
¶Documentation:
man fts_open
Gnulib module: fts
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
fts_read
¶Documentation:
man fts_read
Gnulib module: fts
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
off_t
is a 32-bit type, this function may not
correctly report the size of files or block devices larger than 2 GB and
may not work correctly on huge directories larger than 2 GB. Also, on
platforms where ino_t
is a 32-bit type, this function may report
inode numbers incorrectly. The fix is to use the AC_SYS_LARGEFILE
macro (only on Mac OS X systems).
fts_set
¶Documentation:
man fts_set
Gnulib module: fts
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<getopt.h>
¶getopt_long
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-getopt-long-3.html
Documentation:
Gnulib module: getopt-gnu
Portability problems fixed by Gnulib:
getopt_long
does not obey the combination of
‘+’ and ‘:’ flags in the options string on some platforms:
glibc 2.11.
-W foo
to behave synonymously with --foo
:
glibc 2.11.
getopt_long
does not support the ‘+’ flag in
the options string on some platforms:
macOS 11.1, AIX 5.2, Solaris 10.
optind
after a missing required argument is wrong
on some platforms:
macOS 11.1.
getopt_long
does not obey the ‘-’ flag in the
options string when POSIXLY_CORRECT
is set on some platforms:
Cygwin 1.7.0.
POSIXLY_CORRECT
, when optind
is set to ‘0’:
NetBSD, Cygwin 1.7.0.
getopt_long
does not support options with optional
arguments on some platforms:
macOS 11.1, OpenBSD 4.0, AIX 5.2, IRIX 6.5, Solaris 11 2010-11, Cygwin 1.5.x.
W;
but
there are no long options, on some platforms:
glibc 2.14.
Portability problems not fixed by Gnulib:
getopt_long_only
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-getopt-long-only-3.html
Documentation:
Gnulib module: getopt-gnu
Portability problems fixed by Gnulib:
getopt_long_only
does not obey the combination of
‘+’ and ‘:’ flags in the options string on some platforms:
glibc 2.11.
-W foo
to behave synonymously with --foo
:
glibc 2.11.
getopt_long_only
does not support the ‘+’
flag in the options string on some platforms:
macOS 11.1, AIX 5.2, Solaris 10.
optind
after a missing required argument is wrong
on some platforms:
macOS 11.1.
getopt_long_only
does not obey the ‘-’ flag
in the options string when POSIXLY_CORRECT
is set on some platforms:
Cygwin 1.7.0.
POSIXLY_CORRECT
, when optind
is set to ‘0’:
NetBSD, Cygwin 1.7.0.
getopt_long_only
does not support options with
optional arguments on some platforms:
macOS 11.1, OpenBSD 4.0, AIX 5.2, Solaris 11 2010-11, Cygwin 1.5.x.
W;
but
there are no long options, on some platforms:
glibc 2.14.
Portability problems not fixed by Gnulib:
getopt_long_only
in new programs.
<glob.h>
¶glob_pattern_p
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<gnu/libc-version.h>
¶gnu_get_libc_release
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-gnu-get-libc-version-1.html
Documentation:
man gnu_get_libc_release
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
gnu_get_libc_version
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-gnu-get-libc-version-1.html
Documentation:
man gnu_get_libc_version
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<grp.h>
¶fgetgrent
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
fgetgrent_r
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getgrent_r
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-getgrent-r-1.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getgrouplist
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-getgrouplist-3.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
int
instead of gid_t
parameters
on some platforms: OS X 10.11.
The Gnulib module getugroups
provides a similar API.
initgroups
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-initgroups-3.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
fork
and exec
if
the parent process is multi-threaded. Instead, use getgroups
or
getgrouplist
(or use the gnulib module mgetgroups
)
before forking, and setgroups
in the child.
putgrent
¶Documentation:
man putgrent
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
setgroups
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-setgroups-2.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
GETGROUPS_T
to
the appropriate size (since getgroups
and setgroups
share the same bug).
<gshadow.h>
¶endsgent
fgetsgent
fgetsgent_r
getsgent
getsgent_r
getsgnam
getsgnam_r
putsgent
setsgent
sgetsgent
sgetsgent_r
endsgent
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
fgetsgent
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
fgetsgent_r
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getsgent
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getsgent_r
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getsgnam
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getsgnam_r
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
putsgent
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
setsgent
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
sgetsgent
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
sgetsgent_r
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<ifaddrs.h>
¶getifaddrs
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-getifaddrs.html
Documentation:
man getifaddrs
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
freeifaddrs
¶Documentation:
man freeifaddrs
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<libintl.h>
¶bind_textdomain_codeset
bindtextdomain
dcgettext
dcngettext
dgettext
dngettext
gettext
ngettext
textdomain
bind_textdomain_codeset
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-bind-textdomain-codeset.html
Future POSIX specification:
https://www.austingroupbugs.net/view.php?id=1122
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
bindtextdomain
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-bindtextdomain.html
Future POSIX specification:
https://www.austingroupbugs.net/view.php?id=1122
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
dcgettext
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-dcgettext.html
Future POSIX specification:
https://www.austingroupbugs.net/view.php?id=1122
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
dcngettext
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-dcngettext.html
Future POSIX specification:
https://www.austingroupbugs.net/view.php?id=1122
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
dgettext
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-dgettext.html
Future POSIX specification:
https://www.austingroupbugs.net/view.php?id=1122
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
dngettext
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-dngettext.html
Future POSIX specification:
https://www.austingroupbugs.net/view.php?id=1122
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
gettext
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-gettext.html
Future POSIX specification:
https://www.austingroupbugs.net/view.php?id=1122
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
ngettext
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-ngettext.html
Future POSIX specification:
https://www.austingroupbugs.net/view.php?id=1122
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
textdomain
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-textdomain.html
Future POSIX specification:
https://www.austingroupbugs.net/view.php?id=1122
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<link.h>
¶dl_iterate_phdr
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-dl-iterate-phdr-1.html
Documentation:
man dl_iterate_phdr
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<malloc.h>
¶mallinfo
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
mallinfo2
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
malloc_info
¶Documentation:
man malloc_info
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
malloc_stats
¶Documentation:
man malloc_stats
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
malloc_trim
¶Documentation:
man malloc_trim
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
malloc_usable_size
¶Documentation:
man malloc_usable_size
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
mallopt
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
memalign
¶Documentation:
Gnulib module: memalign
Portability problems fixed by Gnulib:
<stdlib.h>
instead of <malloc.h>
on some platforms:
Solaris 11.
Portability problems not fixed by Gnulib:
The Gnulib module aligned-malloc
provides functions for
allocating and freeing blocks of suitably aligned memory.
pvalloc
¶Documentation:
man pvalloc
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<math.h>
¶drem
dremf
dreml
exp10
exp10f
exp10l
finite
finitef
finitel
gamma
gammaf
gammal
isinff
isinfl
isnanf
isnanl
j0f
j0l
j1f
j1l
jnf
jnl
lgamma_r
lgammaf_r
lgammal_r
matherr
pow10
pow10f
pow10l
scalbf
scalbl
significand
significandf
significandl
sincos
sincosf
sincosl
y0f
y0l
y1f
y1l
ynf
ynl
drem
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-drem.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
dremf
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-dremf.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
dreml
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-dreml.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
exp10
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-exp10.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
exp10f
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-exp10f.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
exp10l
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-exp10l.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
finite
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-finite.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
finitef
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-finitef.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
finitel
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-finitel.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
gamma
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-gamma.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
gammaf
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-gammaf.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
gammal
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-gammal.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
isinff
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
isinfl
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
isnanf
¶Documentation:
Gnulib module: isnanf
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
isnanl
¶Documentation:
Gnulib module: isnanl
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
j0f
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-j0f.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
j0l
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-j0l.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
j1f
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-j1f.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
j1l
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-j1l.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
jnf
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-jnf.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
jnl
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-jnl.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
lgamma_r
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-lgamma-r.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
lgammaf_r
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-lgammaf-r.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
lgammal_r
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-lgammal-r.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
matherr
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-matherr-1.html
Documentation:
man matherr
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pow10
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-pow10.html
Documentation:
man pow10
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pow10f
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-pow10f.html
Documentation:
man pow10f
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pow10l
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-pow10l.html
Documentation:
man pow10l
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
scalbf
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-scalbf.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
scalbl
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-scalbl.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
significand
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-significand.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
significandf
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-significandf.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
significandl
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-significandl.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
sincos
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-sincos.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
sincosf
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-sincosf.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
sincosl
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-sincosl.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
y0f
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-y0f.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
y0l
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-y0l.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
y1f
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-y1f.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
y1l
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-y1l.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
ynf
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-ynf.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
ynl
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-ynl.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<mcheck.h>
¶mcheck
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
mcheck_check_all
¶Documentation:
man mcheck_check_all
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
mcheck_pedantic
¶Documentation:
man mcheck_pedantic
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
mprobe
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
mtrace
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
muntrace
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<mntent.h>
¶addmntent
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
endmntent
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getmntent
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getmntent_r
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
hasmntopt
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
setmntent
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<netdb.h>
¶endnetgrent
gethostbyaddr_r
gethostbyname2
gethostbyname2_r
gethostbyname_r
gethostent_r
getnetbyaddr_r
getnetbyname_r
getnetent_r
getnetgrent
getnetgrent_r
getprotobyname_r
getprotobynumber_r
getprotoent_r
getservbyname_r
getservbyport_r
getservent_r
herror
hstrerror
innetgr
rcmd
rcmd_af
rexec
rexec_af
rresvport
rresvport_af
ruserok
ruserok_af
setnetgrent
endnetgrent
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
gethostbyaddr_r
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-gethostbyaddr-r-3.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
gethostbyname2
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-gethostbyname2-3.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
gethostbyname2_r
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-gethostbyname2-r-3.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
gethostbyname_r
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-gethostbyname-r-3.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
gethostent_r
¶Documentation:
man gethostent_r
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getnetbyaddr_r
¶Documentation:
man getnetbyaddr_r
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getnetbyname_r
¶Documentation:
man getnetbyname_r
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getnetent_r
¶Documentation:
man getnetent_r
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getnetgrent
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getnetgrent_r
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getprotobyname_r
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-getprotobyname-r.html
Documentation:
man getprotobyname_r
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getprotobynumber_r
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-getprotobynumber-r.html
Documentation:
man getprotobynumber_r
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getprotoent_r
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-getprotoent-r.html
Documentation:
man getprotoent_r
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getservbyname_r
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-getservbyname-r.html
Documentation:
man getservbyname_r
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getservbyport_r
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-getservbyport-r.html
Documentation:
man getservbyport_r
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getservent_r
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-getservent-r.html
Documentation:
man getservent_r
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
herror
¶Documentation:
man herror
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
hstrerror
¶Documentation:
man hstrerror
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
innetgr
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
rcmd
¶Documentation:
man rcmd
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
rcmd_af
¶Documentation:
man rcmd_af
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
rexec
¶Documentation:
man rexec
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
rexec_af
¶Documentation:
man rexec_af
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
rresvport
¶Documentation:
man rresvport
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
rresvport_af
¶Documentation:
man rresvport_af
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
ruserok
¶Documentation:
man ruserok
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
ruserok_af
¶Documentation:
man ruserok_af
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
setnetgrent
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<netinet/ether.h>
¶ether_aton
¶Documentation:
man ether_aton
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
ether_aton_r
¶Documentation:
man ether_aton_r
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
ether_hostton
¶Documentation:
man ether_hostton
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
ether_line
¶Documentation:
man ether_line
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
ether_ntoa
¶Documentation:
man ether_ntoa
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
ether_ntoa_r
¶Documentation:
man ether_ntoa_r
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
ether_ntohost
¶Documentation:
man ether_ntohost
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<netinet/in.h>
¶bindresvport
getipv4sourcefilter
getsourcefilter
in6addr_any
in6addr_loopback
inet6_option_alloc
inet6_option_append
inet6_option_find
inet6_option_init
inet6_option_next
inet6_option_space
inet6_opt_append
inet6_opt_find
inet6_opt_finish
inet6_opt_get_val
inet6_opt_init
inet6_opt_next
inet6_opt_set_val
inet6_rth_add
inet6_rth_getaddr
inet6_rth_init
inet6_rth_reverse
inet6_rth_segments
inet6_rth_space
setipv4sourcefilter
setsourcefilter
bindresvport
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-bindresvport-3.html
Documentation:
man bindresvport
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getipv4sourcefilter
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getsourcefilter
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
in6addr_any
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/Host-Address-Data-Type.html.
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
in6addr_loopback
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/Host-Address-Data-Type.html.
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
inet6_option_alloc
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
inet6_option_append
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
inet6_option_find
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
inet6_option_init
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
inet6_option_next
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
inet6_option_space
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
inet6_opt_append
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
inet6_opt_find
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
inet6_opt_finish
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
inet6_opt_get_val
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
inet6_opt_init
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
inet6_opt_next
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
inet6_opt_set_val
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
inet6_rth_add
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
inet6_rth_getaddr
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
inet6_rth_init
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
inet6_rth_reverse
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
inet6_rth_segments
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
inet6_rth_space
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
setipv4sourcefilter
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
setsourcefilter
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<obstack.h>
¶obstack_alloc_failed_handler
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/Preparing-for-Obstacks.html.
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
obstack_exit_failure
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
obstack_free
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/Freeing-Obstack-Objects.html.
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
obstack_printf
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/Dynamic-Output.html.
Gnulib module: obstack-printf or obstack-printf-posix or obstack-printf-gnu
Portability problems fixed by either Gnulib module
obstack-printf
or obstack-printf-posix
or obstack-printf-gnu
:
Portability problems fixed by either Gnulib module obstack-printf-posix
or obstack-printf-gnu
:
hh
, ll
,
j
, t
, z
) on some platforms:
AIX 5.1, HP-UX 11.23, IRIX 6.5, Solaris 9, Cygwin 1.5.24, old mingw, MSVC 9.
"%f"
, "%e"
, "%g"
of Infinity and NaN yields an
incorrect result on some platforms:
AIX 5.2, Solaris 11.0, mingw, MSVC 14.
"%2$s"
, on some platforms:
NetBSD 3.0, mingw, MSVC 14.
'
flag on some platforms:
NetBSD 3.0, Cygwin 1.5.24, mingw, MSVC 14.
"%010f"
of NaN and Infinity yields an incorrect result (padded
with zeroes) on some platforms:
Mac OS X 10.5, FreeBSD 13.0, NetBSD 5.0, AIX 5.2, IRIX 6.5, Solaris 11.0, Cygwin 1.5.x, mingw, MSVC/clang.
"%#.0x"
or "%#.0X"
with a zero argument yields an
incorrect result (non-empty) on some platforms:
Mac OS X 10.6.
Portability problems fixed by Gnulib module obstack-printf-gnu
:
Portability problems not fixed by Gnulib:
%m
directive is not portable, use %s
mapped to an
argument of strerror(errno)
(or a version of strerror_r
)
instead.
obstack_vprintf
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/Variable-Arguments-Output.html.
Gnulib module: obstack-printf or obstack-printf-posix or obstack-printf-gnu
Portability problems fixed by either Gnulib module
obstack-printf
or obstack-printf-posix
or obstack-printf-gnu
:
Portability problems fixed by either Gnulib module obstack-printf-posix
or obstack-printf-gnu
:
hh
, ll
,
j
, t
, z
) on some platforms:
AIX 5.1, HP-UX 11.23, IRIX 6.5, Solaris 9, Cygwin 1.5.24, old mingw, MSVC 9.
"%f"
, "%e"
, "%g"
of Infinity and NaN yields an
incorrect result on some platforms:
AIX 5.2, Solaris 11.0, mingw, MSVC 14.
"%2$s"
, on some platforms:
NetBSD 3.0, mingw, MSVC 14.
'
flag on some platforms:
NetBSD 3.0, Cygwin 1.5.24, mingw, MSVC 14.
"%010f"
of NaN and Infinity yields an incorrect result (padded
with zeroes) on some platforms:
Mac OS X 10.5, FreeBSD 13.0, NetBSD 5.0, AIX 5.2, IRIX 6.5, Solaris 11.0, Cygwin 1.5.x, mingw, MSVC/clang.
"%#.0x"
or "%#.0X"
with a zero argument yields an
incorrect result (non-empty) on some platforms:
Mac OS X 10.6.
Portability problems fixed by Gnulib module obstack-printf-gnu
:
Portability problems not fixed by Gnulib:
%m
directive is not portable, use %s
mapped to an
argument of strerror(errno)
(or a version of strerror_r
)
instead.
<poll.h>
¶ppoll
¶Documentation:
man ppoll
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<printf.h>
¶parse_printf_format
printf_size
printf_size_info
register_printf_function
register_printf_modifier
register_printf_specifier
register_printf_type
parse_printf_format
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/Parsing-a-Template-String.html.
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
printf_size
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/Predefined-Printf-Handlers.html.
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
printf_size_info
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/Predefined-Printf-Handlers.html.
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
register_printf_function
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/Registering-New-Conversions.html.
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
register_printf_modifier
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
register_printf_specifier
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
register_printf_type
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<pthread.h>
¶pthread_attr_getaffinity_np
pthread_attr_setaffinity_np
pthread_attr_getsigmask_np
pthread_attr_setsigmask_np
pthread_clockjoin_np
pthread_cond_clockwait
pthread_getaffinity_np
pthread_getattr_default_np
pthread_getattr_np
pthread_getname_np
pthread_kill_other_threads_np
pthread_mutex_clocklock
pthread_rwlock_clockrdlock
pthread_rwlock_clockwrlock
pthread_rwlockattr_getkind_np
pthread_rwlockattr_setkind_np
pthread_setaffinity_np
pthread_setattr_default_np
pthread_setname_np
pthread_sigqueue
pthread_timedjoin_np
pthread_tryjoin_np
pthread_attr_getaffinity_np
¶Documentation:
man pthread_attr_getaffinity_np
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_attr_setaffinity_np
¶Documentation:
man pthread_attr_setaffinity_np
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_attr_getsigmask_np
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/Initial-Thread-Signal-Mask.html.
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_attr_setsigmask_np
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/Initial-Thread-Signal-Mask.html.
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_clockjoin_np
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_cond_clockwait
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_getaffinity_np
¶Documentation:
man pthread_getaffinity_np
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_getattr_default_np
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_getattr_np
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-pthread-getattr-np-1.html
Documentation:
man pthread_getattr_np
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_getname_np
¶Documentation:
man pthread_getname_np
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_kill_other_threads_np
¶Documentation:
man pthread_kill_other_threads_np
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_mutex_clocklock
¶Documentation: —
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_rwlock_clockrdlock
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_rwlock_clockwrlock
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_rwlockattr_getkind_np
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-pthread-rwlockattr-getkind-np-1.html
Documentation:
man pthread_rwlockattr_getkind_np
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_rwlockattr_setkind_np
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-pthread-rwlockattr-getkind-np-1.html
Documentation:
man pthread_rwlockattr_setkind_np
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_setaffinity_np
¶Documentation:
man pthread_setaffinity_np
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_setattr_default_np
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_setname_np
¶Documentation:
man pthread_setname_np
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
printf
format string,
with the third argument as parameter.
pthread_sigqueue
¶Documentation:
man pthread_sigqueue
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pthread_timedjoin_np
¶Documentation:
man pthread_timedjoin_np
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
libthr
but not in
libpthread
, and it also is missing a declaration.
pthread_tryjoin_np
¶Documentation:
man pthread_tryjoin_np
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<pty.h>
¶forkpty
¶Documentation:
Gnulib module: forkpty
Portability problems fixed by Gnulib:
-lutil
is not required.
-lutil
is
required.
const
.
FreeBSD 13.0, Solaris 11.4, Cygwin 1.7.1.
Portability problems not fixed by Gnulib:
openpty
¶Documentation:
Gnulib module: openpty
Portability problems fixed by Gnulib:
-lutil
is not required.
-lutil
is
required.
const
.
FreeBSD 13.0, Solaris 11.4, Cygwin 1.7.1.
Portability problems not fixed by Gnulib:
<pwd.h>
¶fgetpwent
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
fgetpwent_r
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getpw
¶Documentation:
man getpw
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getpwent_r
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-getpwent-r-1.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
putpwent
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<regex.h>
¶re_comp
re_compile_fastmap
re_compile_pattern
re_exec
re_match
re_match_2
re_search
re_search_2
re_set_registers
re_set_syntax
re_syntax_options
re_comp
¶Documentation:
man re_comp
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
re_compile_fastmap
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
re_compile_pattern
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
re_exec
¶Documentation:
man re_exec
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
re_match
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
re_match_2
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
re_search
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
re_search_2
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
re_set_registers
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
re_set_syntax
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
re_syntax_options
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<regexp.h>
¶advance
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
loc1
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
loc2
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
locs
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
step
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<resolv.h>
¶dn_comp
dn_expand
dn_skipname
res_dnok
res_hnok
res_init
res_mailok
res_mkquery
res_nmkquery
res_nquery
res_nquerydomain
res_nsearch
res_nsend
res_ownok
res_query
res_querydomain
res_search
res_send
dn_comp
¶Documentation:
man dn_comp
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
dn_expand
¶Documentation:
man dn_expand
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
dn_skipname
¶Documentation:
man dn_skipname
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
res_dnok
¶Documentation:
man res_dnok
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
res_hnok
¶Documentation:
man res_hnok
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
res_init
¶Documentation:
man res_init
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
res_mailok
¶Documentation:
man res_mailok
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
res_mkquery
¶Documentation:
man res_mkquery
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
res_nmkquery
¶Documentation:
man res_nmkquery
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
res_nquery
¶Documentation:
man res_nquery
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
res_nquerydomain
¶Documentation:
man res_nquerydomain
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
res_nsearch
¶Documentation:
man res_nsearch
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
res_nsend
¶Documentation:
man res_nsend
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
res_ownok
¶Documentation:
man res_ownok
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
res_query
¶Documentation:
man res_query
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
res_querydomain
¶Documentation:
man res_querydomain
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
res_search
¶Documentation:
man res_search
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
res_send
¶Documentation:
man res_send
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<rpc/auth.h>
¶authdes_create
authdes_pk_create
authnone_create
authunix_create
authunix_create_default
getnetname
host2netname
key_decryptsession
key_decryptsession_pk
key_encryptsession
key_encryptsession_pk
key_gendes
key_get_conv
key_secretkey_is_set
key_setsecret
netname2host
netname2user
user2netname
xdr_des_block
xdr_opaque_auth
authdes_create
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
authdes_pk_create
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
authnone_create
¶Documentation:
man authnone_create
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
authunix_create
¶Documentation:
man authunix_create
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
authunix_create_default
¶Documentation:
man authunix_create_default
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getnetname
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
host2netname
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
key_decryptsession
¶Documentation:
man key_decryptsession
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
key_decryptsession_pk
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
key_encryptsession
¶Documentation:
man key_encryptsession
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
key_encryptsession_pk
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
key_gendes
¶Documentation:
man key_gendes
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
key_get_conv
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
key_secretkey_is_set
¶Documentation:
man key_secretkey_is_set
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
key_setsecret
¶Documentation:
man key_setsecret
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
netname2host
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
netname2user
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
user2netname
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
xdr_des_block
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
xdr_opaque_auth
¶Documentation:
man xdr_opaque_auth
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<rpc/auth_des.h>
¶authdes_getucred
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getpublickey
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getsecretkey
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
rtime
¶Documentation:
man rtime
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<rpc/auth_unix.h>
¶xdr_authunix_parms
¶Documentation:
man xdr_authunix_parms
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<rpc/clnt.h>
¶callrpc
clnt_create
clnt_pcreateerror
clnt_perrno
clnt_perror
clnt_spcreateerror
clnt_sperrno
clnt_sperror
clntraw_create
clnttcp_create
clntudp_bufcreate
clntudp_create
clntunix_create
get_myaddress
getrpcport
rpc_createerr
callrpc
¶Documentation:
man callrpc
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
clnt_create
¶Documentation:
man clnt_create
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
clnt_pcreateerror
¶Documentation:
man clnt_pcreateerror
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
clnt_perrno
¶Documentation:
man clnt_perrno
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
clnt_perror
¶Documentation:
man clnt_perror
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
clnt_spcreateerror
¶Documentation:
man clnt_spcreateerror
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
clnt_sperrno
¶Documentation:
man clnt_sperrno
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
clnt_sperror
¶Documentation:
man clnt_sperror
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
clntraw_create
¶Documentation:
man clntraw_create
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
clnttcp_create
¶Documentation:
man clnttcp_create
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
clntudp_bufcreate
¶Documentation:
man clntudp_bufcreate
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
clntudp_create
¶Documentation:
man clntudp_create
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
clntunix_create
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
get_myaddress
¶Documentation:
man get_myaddress
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getrpcport
¶Documentation:
man getrpcport
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
rpc_createerr
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<rpc/key_prot.h>
¶xdr_cryptkeyarg
xdr_cryptkeyarg2
xdr_cryptkeyres
xdr_getcredres
xdr_key_netstarg
xdr_key_netstres
xdr_keybuf
xdr_keystatus
xdr_netnamestr
xdr_unixcred
xdr_cryptkeyarg
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
xdr_cryptkeyarg2
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
xdr_cryptkeyres
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
xdr_getcredres
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
xdr_key_netstarg
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
xdr_key_netstres
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
xdr_keybuf
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
xdr_keystatus
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
xdr_netnamestr
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
xdr_unixcred
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<rpc/netdb.h>
¶endrpcent
getrpcbyname
getrpcbyname_r
getrpcbynumber
getrpcbynumber_r
getrpcent
getrpcent_r
setrpcent
endrpcent
¶Documentation:
man endrpcent
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getrpcbyname
¶Documentation:
man getrpcbyname
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getrpcbyname_r
¶Documentation:
man getrpcbyname_r
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getrpcbynumber
¶Documentation:
man getrpcbynumber
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getrpcbynumber_r
¶Documentation:
man getrpcbynumber_r
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getrpcent
¶Documentation:
man getrpcent
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getrpcent_r
¶Documentation:
man getrpcent_r
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
setrpcent
¶Documentation:
man setrpcent
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<rpc/pmap_clnt.h>
¶clnt_broadcast
¶Documentation:
man clnt_broadcast
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pmap_getmaps
¶Documentation:
man pmap_getmaps
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pmap_getport
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-pmap-getport-3.html
Documentation:
man pmap_getport
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pmap_rmtcall
¶Documentation:
man pmap_rmtcall
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pmap_set
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-pmap-set-3.html
Documentation:
man pmap_set
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pmap_unset
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-pmap-unset-3.html
Documentation:
man pmap_unset
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<rpc/pmap_prot.h>
¶xdr_pmap
¶Documentation:
man xdr_pmap
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
xdr_pmaplist
¶Documentation:
man xdr_pmaplist
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<rpc/pmap_rmt.h>
¶xdr_rmtcall_args
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
xdr_rmtcallres
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<rpc/rpc_msg.h>
¶xdr_callhdr
¶Documentation:
man xdr_callhdr
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
xdr_callmsg
¶Documentation:
man xdr_callmsg
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
xdr_replymsg
¶Documentation:
man xdr_replymsg
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<rpc/svc.h>
¶svc_exit
svc_fdset
svc_getreq
svc_getreq_common
svc_getreq_poll
svc_getreqset
svc_max_pollfd
svc_pollfd
svc_register
svc_run
svc_sendreply
svc_unregister
svcerr_auth
svcerr_decode
svcerr_noproc
svcerr_noprog
svcerr_progvers
svcerr_systemerr
svcerr_weakauth
svcraw_create
svctcp_create
svcudp_bufcreate
svcudp_create
svcunix_create
xprt_register
xprt_unregister
svc_exit
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
svc_fdset
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
svc_getreq
¶Documentation:
man svc_getreq
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
svc_getreq_common
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
svc_getreq_poll
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
svc_getreqset
¶Documentation:
man svc_getreqset
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
svc_max_pollfd
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
svc_pollfd
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
svc_register
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-svc-register-3.html
Documentation:
man svc_register
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
svc_run
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-svc-run-3.html
Documentation:
man svc_run
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
svc_sendreply
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-svc-sendreply-3.html
Documentation:
man svc_sendreply
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
svc_unregister
¶Documentation:
man svc_unregister
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
svcerr_auth
¶Documentation:
man svcerr_auth
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
svcerr_decode
¶Documentation:
man svcerr_decode
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
svcerr_noproc
¶Documentation:
man svcerr_noproc
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
svcerr_noprog
¶Documentation:
man svcerr_noprog
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
svcerr_progvers
¶Documentation:
man svcerr_progvers
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
svcerr_systemerr
¶Documentation:
man svcerr_systemerr
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
svcerr_weakauth
¶Documentation:
man svcerr_weakauth
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
svcraw_create
¶Documentation:
man svcraw_create
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
svctcp_create
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-svctcp-create-3.html
Documentation:
man svctcp_create
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
svcudp_bufcreate
¶Documentation:
man svcudp_bufcreate
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
svcudp_create
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-svcudp-create-3.html
Documentation:
man svcudp_create
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
svcunix_create
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
xprt_register
¶Documentation:
man xprt_register
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
xprt_unregister
¶Documentation:
man xprt_unregister
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<rpc/xdr.h>
¶xdr_array
xdr_bool
xdr_bytes
xdr_char
xdr_double
xdr_enum
xdr_float
xdr_free
xdr_hyper
xdr_int
xdr_int16_t
xdr_int32_t
xdr_int64_t
xdr_int8_t
xdr_long
xdr_longlong_t
xdr_netobj
xdr_opaque
xdr_pointer
xdr_quad_t
xdr_reference
xdr_short
xdr_sizeof
xdr_string
xdr_u_char
xdr_u_hyper
xdr_u_int
xdr_u_long
xdr_u_longlong_t
xdr_u_quad_t
xdr_u_short
xdr_uint16_t
xdr_uint32_t
xdr_uint64_t
xdr_uint8_t
xdr_union
xdr_vector
xdr_void
xdr_wrapstring
xdrmem_create
xdrrec_create
xdrrec_endofrecord
xdrrec_eof
xdrrec_skiprecord
xdrstdio_create
xdr_array
¶Documentation:
man xdr_array
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
xdr_bool
¶Documentation:
man xdr_bool
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
xdr_bytes
¶Documentation:
man xdr_bytes
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
xdr_char
¶Documentation:
man xdr_char
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
xdr_double
¶Documentation:
man xdr_double
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
xdr_enum
¶Documentation:
man xdr_enum
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
xdr_float
¶Documentation:
man xdr_float
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
xdr_free
¶Documentation:
man xdr_free
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
xdr_hyper
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
xdr_int
¶Documentation:
man xdr_int
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
xdr_int16_t
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
xdr_int32_t
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
xdr_int64_t
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
xdr_int8_t
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
xdr_long
¶Documentation:
man xdr_long
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
xdr_longlong_t
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
xdr_netobj
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
xdr_opaque
¶Documentation:
man xdr_opaque
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
xdr_pointer
¶Documentation:
man xdr_pointer
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
xdr_quad_t
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
xdr_reference
¶Documentation:
man xdr_reference
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
xdr_short
¶Documentation:
man xdr_short
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
xdr_sizeof
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
xdr_string
¶Documentation:
man xdr_string
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
xdr_u_char
¶Documentation:
man xdr_u_char
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
xdr_u_hyper
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
xdr_u_int
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-xdr-u-int-3.html
Documentation:
man xdr_u_int
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
xdr_u_long
¶Documentation:
man xdr_u_long
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
xdr_u_longlong_t
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
xdr_u_quad_t
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
xdr_u_short
¶Documentation:
man xdr_u_short
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
xdr_uint16_t
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
xdr_uint32_t
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
xdr_uint64_t
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
xdr_uint8_t
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
xdr_union
¶Documentation:
man xdr_union
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
xdr_vector
¶Documentation:
man xdr_vector
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
xdr_void
¶Documentation:
man xdr_void
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
xdr_wrapstring
¶Documentation:
man xdr_wrapstring
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
xdrmem_create
¶Documentation:
man xdrmem_create
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
xdrrec_create
¶Documentation:
man xdrrec_create
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
xdrrec_endofrecord
¶Documentation:
man xdrrec_endofrecord
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
xdrrec_eof
¶Documentation:
man xdrrec_eof
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
xdrrec_skiprecord
¶Documentation:
man xdrrec_skiprecord
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
xdrstdio_create
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-xdrstdio-create-3.html
Documentation:
man xdrstdio_create
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<rpcsvc/nislib.h>
¶nis_add
nis_add_entry
nis_addmember
nis_checkpoint
nis_clone_object
nis_creategroup
nis_destroy_object
nis_destroygroup
nis_dir_cmp
nis_domain_of
nis_domain_of_r
nis_first_entry
nis_freenames
nis_freeresult
nis_freeservlist
nis_freetags
nis_getnames
nis_getservlist
nis_ismember
nis_leaf_of
nis_leaf_of_r
nis_lerror
nis_list
nis_local_directory
nis_local_group
nis_local_host
nis_local_principal
nis_lookup
nis_mkdir
nis_modify
nis_modify_entry
nis_name_of
nis_name_of_r
nis_next_entry
nis_perror
nis_ping
nis_print_directory
nis_print_entry
nis_print_group
nis_print_group_entry
nis_print_link
nis_print_object
nis_print_result
nis_print_rights
nis_print_table
nis_remove
nis_remove_entry
nis_removemember
nis_rmdir
nis_servstate
nis_sperrno
nis_sperror
nis_sperror_r
nis_stats
nis_verifygroup
nis_add
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
nis_add_entry
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
nis_addmember
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
nis_checkpoint
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
nis_clone_object
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
nis_creategroup
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
nis_destroy_object
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
nis_destroygroup
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
nis_dir_cmp
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
nis_domain_of
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
nis_domain_of_r
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
nis_first_entry
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
nis_freenames
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
nis_freeresult
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
nis_freeservlist
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
nis_freetags
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
nis_getnames
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
nis_getservlist
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
nis_ismember
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
nis_leaf_of
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
nis_leaf_of_r
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
nis_lerror
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
nis_list
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
nis_local_directory
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
nis_local_group
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
nis_local_host
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
nis_local_principal
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
nis_lookup
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
nis_mkdir
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
nis_modify
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
nis_modify_entry
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
nis_name_of
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
nis_name_of_r
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
nis_next_entry
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
nis_perror
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
nis_ping
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
nis_print_directory
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
nis_print_entry
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
nis_print_group
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
nis_print_group_entry
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
nis_print_link
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
nis_print_object
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
nis_print_result
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
nis_print_rights
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
nis_print_table
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
nis_remove
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
nis_remove_entry
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
nis_removemember
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
nis_rmdir
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
nis_servstate
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
nis_sperrno
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
nis_sperror
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
nis_sperror_r
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
nis_stats
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
nis_verifygroup
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<rpcsvc/nis_callback.h>
¶xdr_cback_data
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
xdr_obj_p
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<rpcsvc/yp.h>
¶xdr_domainname
xdr_keydat
xdr_valdat
xdr_ypbind_resptype
xdr_ypmap_parms
xdr_ypmaplist
xdr_yppushresp_xfr
xdr_ypreq_key
xdr_ypreq_nokey
xdr_ypreq_xfr
xdr_ypresp_all
xdr_ypresp_key_val
xdr_ypresp_maplist
xdr_ypresp_master
xdr_ypresp_order
xdr_ypresp_val
xdr_ypresp_xfr
xdr_ypstat
xdr_ypxfrstat
xdr_domainname
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
xdr_keydat
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
xdr_valdat
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
xdr_ypbind_resptype
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
xdr_ypmap_parms
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
xdr_ypmaplist
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
xdr_yppushresp_xfr
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
xdr_ypreq_key
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
xdr_ypreq_nokey
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
xdr_ypreq_xfr
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
xdr_ypresp_all
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
xdr_ypresp_key_val
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
xdr_ypresp_maplist
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
xdr_ypresp_master
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
xdr_ypresp_order
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
xdr_ypresp_val
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
xdr_ypresp_xfr
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
xdr_ypstat
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
xdr_ypxfrstat
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<rpcsvc/ypclnt.h>
¶yp_all
yp_bind
yp_first
yp_get_default_domain
yp_master
yp_match
yp_next
yp_order
yp_unbind
ypbinderr_string
yperr_string
ypprot_err
yp_all
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
yp_bind
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
yp_first
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
yp_get_default_domain
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
yp_master
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
yp_match
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
yp_next
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
yp_order
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
yp_unbind
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
ypbinderr_string
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
yperr_string
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
ypprot_err
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<sched.h>
¶clone
¶Documentation:
man clone
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getcpu
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
sched_getaffinity
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-sched-getaffinity.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
sched_getcpu
¶Documentation:
man sched_getcpu
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
sched_setaffinity
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-sched-setaffinity.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
setns
¶Documentation:
man setns
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<search.h>
¶hcreate_r
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-hcreate-r.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
hdestroy_r
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-hdestroy-r.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
hsearch_r
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-hsearch-r.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
tdestroy
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
twalk_r
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<selinux/selinux.h>
¶fgetfilecon
¶Documentation:
man fgetfilecon
Gnulib module: selinux-h
Portability problems fixed by Gnulib:
errno
to ENOTSUP
and returns ‘-1’.
fgetfilecon
function that insulates the caller from API-nonconforming behavior.
Without this wrapper, fgetfilecon
can return ‘0’ and set
the context
pointer to NULL, and in another scenario can return
‘10’ and set the context
pointer to ‘unlabeled’.
This wrapper returns ‘-1’ in each case and sets errno
to
ENOTSUP
and ENODATA
respectively.
While the conditions that can provoke such behavior are rare, the
average caller does not handle them because the possibility of such
behavior is not documented.
Portability problems not fixed by Gnulib:
getfilecon
¶Documentation:
man getfilecon
Gnulib module: selinux-h
Portability problems fixed by Gnulib:
errno
to ENOTSUP
and returns ‘-1’.
getfilecon
function that insulates the caller from API-nonconforming behavior.
Without this wrapper, getfilecon
can return ‘0’ and set
the context
pointer to NULL, and in another scenario can return
‘10’ and set the context
pointer to ‘unlabeled’.
This wrapper returns ‘-1’ in each case and sets errno
to
ENOTSUP
and ENODATA
respectively.
While the conditions that can provoke such behavior are rare, the
average caller does not handle them because the possibility of such
behavior is not documented.
Portability problems not fixed by Gnulib:
lgetfilecon
¶Documentation:
man lgetfilecon
Gnulib module: selinux-h
Portability problems fixed by Gnulib:
errno
to ENOTSUP
and returns ‘-1’.
lgetfilecon
function that insulates the caller from API-nonconforming behavior.
Without this wrapper, lgetfilecon
can return ‘0’ and set
the context
pointer to NULL, and in another scenario can return
‘10’ and set the context
pointer to ‘unlabeled’.
This wrapper returns ‘-1’ in each case and sets errno
to
ENOTSUP
and ENODATA
respectively.
While the conditions that can provoke such behavior are rare, the
average caller does not handle them because the possibility of such
behavior is not documented.
Portability problems not fixed by Gnulib:
<semaphore.h>
¶sem_clockwait
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<shadow.h>
¶endspent
fgetspent
fgetspent_r
getspent
getspent_r
getspnam
getspnam_r
lckpwdf
putspent
setspent
sgetspent
sgetspent_r
ulckpwdf
endspent
¶Documentation:
man endspent
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
fgetspent
¶Documentation:
man fgetspent
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
fgetspent_r
¶Documentation:
man fgetspent_r
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getspent
¶Documentation:
man getspent
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getspent_r
¶Documentation:
man getspent_r
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getspnam
¶Documentation:
man getspnam
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getspnam_r
¶Documentation:
man getspnam_r
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
lckpwdf
¶Documentation:
man lckpwdf
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
putspent
¶Documentation:
man putspent
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
setspent
¶Documentation:
man setspent
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
sgetspent
¶Documentation:
man sgetspent
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
sgetspent_r
¶Documentation:
man sgetspent_r
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
ulckpwdf
¶Documentation:
man ulckpwdf
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<signal.h>
¶gsignal
sigandset
sigblock
siggetmask
sigisemptyset
sigorset
sigreturn
sigsetmask
sigstack
sigvec
ssignal
sys_siglist
sysv_signal
tgkill
gsignal
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
sigandset
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-sigandset.html
Documentation:
man sigandset
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
sigblock
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
siggetmask
¶Documentation:
man siggetmask
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
sigisemptyset
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-sigisemptyset.html
Documentation:
man sigisemptyset
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
sigorset
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-sigorset.html
Documentation:
man sigorset
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
sigreturn
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-sigreturn-2.html
Documentation:
man sigreturn
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
sigsetmask
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
sigstack
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
sigvec
¶Documentation:
man sigvec
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
ssignal
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
sys_siglist
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/Signal-Messages.html.
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
sysv_signal
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
tgkill
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<spawn.h>
¶posix_spawn_file_actions_addchdir_np
posix_spawn_file_actions_addclosefrom_np
posix_spawn_file_actions_addfchdir_np
posix_spawn_file_actions_addchdir_np
¶Future POSIX specification:
https://www.austingroupbugs.net/view.php?id=1208
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
Note: Gnulib has a module posix_spawn_file_actions_addchdir
that
provides equivalent functionality, just without the suffix _np
.
posix_spawn_file_actions_addclosefrom_np
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
posix_spawn_file_actions_addfchdir_np
¶Future POSIX specification:
https://www.austingroupbugs.net/view.php?id=1208
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
Note: Gnulib has a module posix_spawn_file_actions_addfchdir
that
provides equivalent functionality, just without the suffix _np
.
<stdio.h>
¶asprintf
cuserid
clearerr_unlocked
fcloseall
feof_unlocked
ferror_unlocked
fflush_unlocked
fgetc_unlocked
fgets_unlocked
fileno_unlocked
fopencookie
fputc_unlocked
fputs_unlocked
fread_unlocked
fwrite_unlocked
getw
putw
renameat2
setbuffer
setlinebuf
sys_errlist
sys_nerr
tmpnam_r
vasprintf
asprintf
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-asprintf.html
Documentation:
Gnulib module: vasprintf or vasprintf-posix or vasprintf-gnu
Portability problems fixed by either Gnulib module vasprintf
or vasprintf-posix
or vasprintf-gnu
:
Portability problems fixed by either Gnulib module vasprintf-posix
or vasprintf-gnu
:
hh
, ll
,
j
, t
, z
) on some platforms:
Cygwin 1.5.24.
"%f"
, "%e"
, "%g"
of Infinity and NaN yields an
incorrect result on some platforms:
Solaris 11.0.
"%2$s"
, on some platforms:
NetBSD 3.0.
'
flag on some platforms:
NetBSD 3.0, Cygwin 1.5.24.
"%010f"
of NaN and Infinity yields an incorrect result (padded
with zeroes) on some platforms:
Mac OS X 10.5, FreeBSD 6.0, NetBSD 5.0, Solaris 11.0, Cygwin 1.5.x.
"%#.0x"
or "%#.0X"
with a zero argument yields an
incorrect result (non-empty) on some platforms:
Mac OS X 10.6.
Portability problems fixed by Gnulib module vasprintf-gnu
:
Portability problems not fixed by Gnulib:
%m
directive is not portable, use %s
mapped to an
argument of strerror(errno)
(or a version of strerror_r
)
instead.
cuserid
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
clearerr_unlocked
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-clearerr-unlocked-1.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
fcloseall
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
void
instead of int
on some platforms:
FreeBSD 13.0.
feof_unlocked
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-feof-unlocked-1.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
ferror_unlocked
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-ferror-unlocked-1.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
fflush_unlocked
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-fflush-unlocked-1.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
fgetc_unlocked
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-fgetc-unlocked-1.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
fgets_unlocked
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-fgets-unlocked-1.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
fileno_unlocked
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-fileno-unlocked-1.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
fopencookie
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
fputc_unlocked
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-fputc-unlocked-1.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
fputs_unlocked
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-fputs-unlocked-1.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
fread_unlocked
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-fread-unlocked-1.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
fwrite_unlocked
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-fwrite-unlocked-1.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getw
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
putw
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
renameat2
¶Documentation:
man renameat2
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
setbuffer
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-setbuffer-3.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
setlinebuf
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
sys_errlist
¶Documentation:
man sys_errlist
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
sys_nerr
¶Documentation:
man sys_nerr
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
tmpnam_r
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
vasprintf
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-vasprintf.html
Documentation:
Gnulib module: vasprintf or vasprintf-posix or vasprintf-gnu
Portability problems fixed by either Gnulib module vasprintf
or vasprintf-posix
or vasprintf-gnu
:
Portability problems fixed by either Gnulib module vasprintf-posix
or vasprintf-gnu
:
hh
, ll
,
j
, t
, z
) on some platforms:
Cygwin 1.5.24.
"%f"
, "%e"
, "%g"
of Infinity and NaN yields an
incorrect result on some platforms:
Solaris 11.0.
"%2$s"
, on some platforms:
NetBSD 3.0.
'
flag on some platforms:
NetBSD 3.0, Cygwin 1.5.24.
"%010f"
of NaN and Infinity yields an incorrect result (padded
with zeroes) on some platforms:
Mac OS X 10.5, FreeBSD 6.0, NetBSD 5.0, Solaris 11.0, Cygwin 1.5.x.
"%#.0x"
or "%#.0X"
with a zero argument yields an
incorrect result (non-empty) on some platforms:
Mac OS X 10.6.
Portability problems fixed by Gnulib module vasprintf-gnu
:
Portability problems not fixed by Gnulib:
%m
directive is not portable, use %s
mapped to an
argument of strerror(errno)
(or a version of strerror_r
)
instead.
<stdlib.h>
¶canonicalize_file_name
cfree
clearenv
drand48_r
ecvt_r
erand48_r
fcvt_r
getloadavg
getpt
initstate_r
jrand48_r
lcong48_r
lrand48_r
mkostemp
mkostemps
mkstemps
mrand48_r
nrand48_r
on_exit
ptsname_r
qecvt
qecvt_r
qfcvt
qfcvt_r
qgcvt
qsort_r
random_r
rpmatch
secure_getenv
seed48_r
setstate_r
srand48_r
srandom_r
strtod_l
strtof_l
strtol_l
strtold_l
strtoll_l
strtoq
strtoul_l
strtoull_l
strtouq
valloc
canonicalize_file_name
¶Documentation:
Gnulib module: canonicalize-lgpl
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
cfree
¶Documentation:
man cfree
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
clearenv
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
drand48_r
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-drand48-r-1.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
ecvt_r
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
erand48_r
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-erand48-r-1.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
fcvt_r
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getloadavg
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-getloadavg-3.html
Documentation:
Gnulib module: getloadavg
Portability problems fixed by Gnulib:
<sys/loadavg.h>
, not <stdlib.h>
,
on some platforms:
Solaris 11.4.
Portability problems not fixed by Gnulib:
getpt
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
initstate_r
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-initstate-r-1.html
Documentation:
Gnulib module: random_r
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
jrand48_r
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-jrand48-r-1.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
lcong48_r
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-lcong48-r-1.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
lrand48_r
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-lrand48-r-1.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
mkostemp
¶Documentation:
man mkostemp
Gnulib module: mkostemp
Portability problems fixed by Gnulib:
<unistd.h>
instead of <stdlib.h>
on some platforms:
macOS 11.1.
off_t
is a 32-bit type, mkostemp
may not work
correctly to create files larger than 2 GB. (Cf. AC_SYS_LARGEFILE
.)
Portability problems not fixed by Gnulib:
The gnulib module clean-temp
can create temporary files that will not
be left behind after signals such as SIGINT.
mkostemps
¶Documentation:
man mkostemps
Gnulib module: mkostemps
Portability problems fixed by Gnulib:
<unistd.h>
instead of <stdlib.h>
on some platforms:
macOS 11.1.
off_t
is a 32-bit type, mkostemps
may not work
correctly to create files larger than 2 GB. (Cf. AC_SYS_LARGEFILE
.)
Portability problems not fixed by Gnulib:
The gnulib module clean-temp
can create temporary files that will not
be left behind after signals such as SIGINT.
mkstemps
¶Documentation:
man mkstemps
Gnulib module: mkstemps
Portability problems fixed by Gnulib:
<unistd.h>
instead of <stdlib.h>
on some platforms:
macOS 11.1.
off_t
is a 32-bit type, mkstemps
may not work
correctly to create files larger than 2 GB. (Cf. AC_SYS_LARGEFILE
.)
Portability problems not fixed by Gnulib:
The gnulib module clean-temp
can create temporary files that will not
be left behind after signals such as SIGINT.
mrand48_r
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-mrand48-r-1.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
nrand48_r
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-nrand48-r-1.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
on_exit
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
ptsname_r
¶Documentation:
Gnulib module: ptsname_r
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
Note: Portable programs should expect to find the error code as the
return value of this function, not as the value of errno
.
This is needed for compatibility with musl libc and with the
forthcoming POSIX Issue 8.
qecvt
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
qecvt_r
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
qfcvt
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
qfcvt_r
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
qgcvt
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
qsort_r
¶Documentation:
man qsort_r
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
random_r
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-random-r-1.html
Documentation:
Gnulib module: random_r
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
rpmatch
¶Documentation:
Gnulib module: rpmatch
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
secure_getenv
¶Documentation:
Gnulib module: secure_getenv
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
seed48_r
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-seed48-r-1.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
setstate_r
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-setstate-r-1.html
Documentation:
Gnulib module: random_r
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
srand48_r
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-srand48-r-1.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
srandom_r
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-srandom-r-1.html
Documentation:
Gnulib module: random_r
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
strtod_l
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
strtof_l
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
strtol_l
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
strtold_l
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
strtoll_l
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
strtoq
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-strtoq-3.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
strtoul_l
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
strtoull_l
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
strtouq
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-strtouq-3.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
valloc
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<string.h>
¶explicit_bzero
ffsl
ffsll
memfrob
memmem
mempcpy
memrchr
rawmemchr
sigabbrev_np
sigdescr_np
strcasestr
strchrnul
strerrordesc_np
strerrorname_np
strfry
strsep
strverscmp
explicit_bzero
¶Documentation:
Gnulib module: explicit_bzero
The explicit_bzero
function is an approximation to what is
needed, and does not suffice in general to erase information.
Although calling explicit_bzero
should clear the memory in
question, the information that was in memory may still be available
elsewhere on the machine. Proper implementation of information
erasure requires support from levels below C code.
C23 specifies the function memset_explicit
, which should be
preferred to explicit_bzero
in new code.
See memset_explicit
.
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
ffsl
¶Documentation:
man ffsl
Gnulib module: ffsl
Portability problems fixed by Gnulib:
<strings.h>
instead of <string.h>
on some platforms:
AIX 7.2, Android 13.
Portability problems not fixed by Gnulib:
ffsll
¶Documentation:
man ffsll
Gnulib module: ffsll
Portability problems fixed by Gnulib:
<strings.h>
instead of <string.h>
on some platforms:
AIX 7.2, Android 13.
Portability problems not fixed by Gnulib:
memfrob
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
memmem
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-memmem-3.html
Documentation:
Gnulib module: memmem or memmem-simple
Both modules implement the same replacement for the memmem
function
with the memmem
module providing a replacement on more platforms where
the existing memmem
function has a quadratic worst-case complexity.
Portability problems fixed by either Gnulib module memmem-simple
or memmem
:
Performance problems fixed by Gnulib module memmem
:
Portability problems not fixed by Gnulib:
mempcpy
¶Documentation:
Gnulib module: mempcpy
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
memrchr
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-memrchr.html
Documentation:
Gnulib module: memrchr
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
rawmemchr
¶Documentation:
Gnulib module: rawmemchr
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
sigabbrev_np
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/Signal-Messages.html.
Gnulib module: sigabbrev_np
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
Note: Gnulib has a module sig2str
that contains an equivalent function
and also one that does the opposite conversion, from an abbreviated signal name
to a signal number.
sigdescr_np
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/Signal-Messages.html.
Gnulib module: sigdescr_np
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
Note: This function is hardly useful, because it returns English strings, not
internationalized strings. Better use the function strsignal
, which
returns internationalized strings.
strcasestr
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-strcasestr.html
Documentation:
Gnulib module: strcasestr or strcasestr-simple
Portability problems fixed by either Gnulib module strcasestr-simple
or strcasestr
:
Portability problems fixed by Gnulib module strcasestr
:
Portability problems not fixed by Gnulib:
strchrnul
¶Documentation:
Gnulib module: strchrnul
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
strerrordesc_np
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/Error-Messages.html.
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
strerrorname_np
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/Error-Messages.html.
Gnulib module: strerrorname_np
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
strfry
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
strsep
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-strsep-3.html
Documentation:
Gnulib module: strsep
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
strverscmp
¶Documentation:
Gnulib module: strverscmp
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
strverscmp ("B0075022800016.gbp.corp.com",
"B007502357019.GBP.CORP.COM")
does not yield a negative number as it
should):
glibc 2.9
<sys/auxv.h>
¶getauxval
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<sys/capability.h>
¶capget
¶Documentation:
man capget
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
capset
¶Documentation:
man capset
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<sys/epoll.h>
¶epoll_create
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-epoll-create-1.html
Documentation:
man epoll_create
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
epoll_create1
¶Documentation:
man epoll_create1
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
epoll_ctl
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-epoll-ctl-1.html
Documentation:
man epoll_ctl
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
epoll_pwait
¶Documentation:
man epoll_pwait
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
epoll_wait
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-epoll-wait-1.html
Documentation:
man epoll_wait
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<sys/eventfd.h>
¶eventfd
¶Documentation:
man eventfd
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
eventfd_read
¶Documentation:
man eventfd_read
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
eventfd_write
¶Documentation:
man eventfd_write
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<sys/fanotify.h>
¶fanotify_init
¶Documentation:
man fanotify_init
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
fanotify_mark
¶Documentation:
man fanotify_mark
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<sys/file.h>
¶flock
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-flock-2.html
Documentation:
man flock
Gnulib module: flock
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<sys/fsuid.h>
¶setfsgid
¶Documentation:
man setfsgid
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
setfsuid
¶Documentation:
man setfsuid
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<sys/gmon.h>
¶monstartup
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<sys/inotify.h>
¶inotify_add_watch
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-inotify-add-watch.html
Documentation:
man inotify_add_watch
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
inotify_init
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-inotify-init.html
Documentation:
man inotify_init
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
inotify_init1
¶Documentation:
man inotify_init1
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
inotify_rm_watch
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-inotify-rm-watch.html
Documentation:
man inotify_rm_watch
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<sys/io.h>
, <sys/perm.h>
¶ioperm
¶Documentation:
man ioperm
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
iopl
¶Documentation:
man iopl
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<sys/kdaemon.h>
¶bdflush
¶Documentation:
man bdflush
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<sys/klog.h>
¶klogctl
¶Documentation:
man klogctl
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<sys/mman.h>
¶madvise
memfd_create
mincore
mlock2
mremap
pkey_alloc
pkey_free
pkey_get
pkey_mprotect
pkey_set
remap_file_pages
madvise
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
memfd_create
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
mincore
¶Documentation:
man mincore
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
mlock2
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
mremap
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-mremap.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pkey_alloc
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pkey_free
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pkey_get
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/Memory-Protection.html.
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pkey_mprotect
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pkey_set
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/Memory-Protection.html.
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
remap_file_pages
¶Documentation:
man remap_file_pages
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<sys/mount.h>
¶mount
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
umount
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
umount2
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<sys/personality.h>
¶personality
¶Documentation:
man personality
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<sys/prctl.h>
¶prctl
¶Documentation:
man prctl
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<sys/profil.h>
¶sprofil
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<sys/ptrace.h>
¶ptrace
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-ptrace-1.html
Documentation:
man ptrace
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<sys/quota.h>
¶quotactl
¶Documentation:
man quotactl
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<sys/random.h>
¶getentropy
¶Future POSIX specification:
https://www.austingroupbugs.net/view.php?id=1134
Documentation:
Gnulib module: getentropy
Portability problems fixed by Gnulib:
<sys/random.h>
, not in <unistd.h>
,
on some platforms:
macOS 11.1, Solaris 11.4, Android 9.0.
Portability problems not fixed by Gnulib:
Although this function is intended to produce random data, the data’s security properties may not be appropriate for your application. For example, identical “random” data streams might be produced by rebooted virtual machines. If this is of concern you may need to use additional techniques such as hedging.1
Related modules include getrandom
, which has a more-flexible
but more-complex API, and crypto/gc-random
, which is likely a
better match for code already using the other crypto
APIs.
getrandom
¶Documentation:
Gnulib module: getrandom
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
GRND_INSECURE
flag is missing on some platforms:
glibc 2.34, macOS 10.15, GNU/kFreeBSD, FreeBSD 12.0, OpenBSD 6.7,
Minix 3.3, Haiku.
GRND_RANDOM
flag has different effects on different platforms.
Some platforms ignore the flag, or yield data that can fail to be
random in some cases.
Although this function is intended to produce random data, the data’s security properties may not be appropriate for your application. For example, identical “random” data streams might be produced by rebooted virtual machines. If this is of concern you may need to use additional techniques such as hedging.2
Related modules include getentropy
, which has a simpler but
more-limited API, and crypto/gc-random
, which is likely a
better match for code already using the other crypto
APIs.
<sys/reboot.h>
¶reboot
¶Documentation:
man reboot
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<sys/resource.h>
¶prlimit
¶Documentation:
man prlimit
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<sys/sem.h>
¶semtimedop
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<sys/sendfile.h>
¶sendfile
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-sendfile.html
Documentation:
man sendfile
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
off_t
is a 32-bit type, this function may not
work correctly on files larger than 2 GB. The fix is to use the
AC_SYS_LARGEFILE
macro.
<sys/signalfd.h>
¶signalfd
¶Documentation:
man signalfd
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<sys/single_threaded.h>
¶__libc_single_threaded
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/Single_002dThreaded.html.
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<sys/socket.h>
¶accept4
¶Documentation:
man accept4
Gnulib module: accept4
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
isfdtype
¶Documentation:
man isfdtype
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
recvmmsg
¶Documentation:
man recvmmsg
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
sendmmsg
¶Documentation:
man sendmmsg
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<sys/stat.h>
¶getumask
¶Documentation:
Gnulib module: getumask
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
lchmod
¶Gnulib module: lchmod
Portability problems fixed by Gnulib:
errno
set to ENOSYS
,
even when the file is not a symbolic link:
GNU/Linux with glibc 2.31.
Portability problems not fixed by Gnulib:
errno
set to EMFILE
or ENFILE
,
and it fails with errno
set to EOPNOTSUPP
if the
/proc file system is not mounted:
GNU/Linux with glibc 2.34.
statx
¶Documentation:
man statx
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<sys/statfs.h>
¶fstatfs
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-fstatfs-2.html
Documentation:
man fstatfs
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
f_blocks
in ‘struct statfs’ is a 32-bit
value, this function may not work correctly on files systems larger than
4 TiB. The fix is to use the AC_SYS_LARGEFILE
macro. This affects
Mac OS X.
statfs
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-statfs-2.html
Documentation:
man statfs
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
f_blocks
in ‘struct statfs’ is a 32-bit
value, this function may not work correctly on files systems larger than
4 TiB. The fix is to use the AC_SYS_LARGEFILE
macro. This affects
Mac OS X.
<sys/swap.h>
¶swapoff
¶Documentation:
man swapoff
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
swapon
¶Documentation:
man swapon
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<sys/sysctl.h>
¶sysctl
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<sys/sysinfo.h>
¶get_avphys_pages
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
get_nprocs
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
Gnulib provides the module nproc
that performs a similar
function but is portable to more systems.
get_nprocs_conf
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
get_phys_pages
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
sysinfo
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-sysinfo-1.html
Documentation:
man sysinfo
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<sys/syslog.h>
¶vsyslog
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-vsyslog-3.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<sys/sysmacros.h>
¶gnu_dev_major
¶Documentation:
man gnu_dev_major
Gnulib module: —
Portability problems fixed by Gnulib:
AC_HEADER_MAJOR
macro in Autoconf 2.69 and earlier fails to
set MAJOR_IN_SYSMACROS
when it detects namespace pollution in
sys/types.h; which in turn provokes deprecation warnings in
glibc 2.25.
Portability problems not fixed by Gnulib:
gnu_dev_makedev
¶Documentation:
man gnu_dev_makedev
Gnulib module: —
Portability problems fixed by Gnulib:
AC_HEADER_MAJOR
macro in Autoconf 2.69 and earlier fails to
set MAJOR_IN_SYSMACROS
when it detects namespace pollution in
sys/types.h; which in turn provokes deprecation warnings in
glibc 2.25.
Portability problems not fixed by Gnulib:
gnu_dev_minor
¶Documentation:
man gnu_dev_minor
Gnulib module: —
Portability problems fixed by Gnulib:
AC_HEADER_MAJOR
macro in Autoconf 2.69 and earlier fails to
set MAJOR_IN_SYSMACROS
when it detects namespace pollution in
sys/types.h; which in turn provokes deprecation warnings in
glibc 2.25.
Portability problems not fixed by Gnulib:
<sys/time.h>
¶adjtime
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-adjtime-2.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
futimes
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-futimes.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
futimens(fd,times)
instead.
futimesat
¶Documentation:
man futimesat
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
file ? utimensat(fd, file, times, 0) : futimens(fd, times)
or the gnulib module fdutimensat
, instead.
lutimes
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
utimensat(AT_FDCWD,file,times,AT_SYMLINK_NOFOLLOW)
, or the
gnulib module utimens
, instead.
lstat
modifies the access time of
symlinks on some platforms, so lutimes
can only effectively
change modification time:
Cygwin.
settimeofday
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<sys/timerfd.h>
¶timerfd_create
¶Documentation:
man timerfd_create
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
timerfd_gettime
¶Documentation:
man timerfd_gettime
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
timerfd_settime
¶Documentation:
man timerfd_settime
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<sys/timex.h>
¶adjtimex
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
ntp_adjtime
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
ntp_gettime
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
ntp_gettimex
¶Documentation:
man ntp_gettimex
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<sys/uio.h>
¶preadv
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
off_t
is a 32-bit type, this function may not
work correctly on files larger than 2 GB. The fix is to use the
AC_SYS_LARGEFILE
macro.
preadv2
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
process_vm_readv
¶Documentation:
man process_vm_readv
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
process_vm_writev
¶Documentation:
man process_vm_writev
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pwritev
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
off_t
is a 32-bit type, this function may not
work correctly on files larger than 2 GB. The fix is to use the
AC_SYS_LARGEFILE
macro.
pwritev2
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<sys/ustat.h>
¶<sys/vlimit.h>
¶vlimit
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<sys/wait.h>
¶wait3
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wait4
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-wait4-2.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<sys/xattr.h>
¶fgetxattr
flistxattr
fremovexattr
fsetxattr
getxattr
lgetxattr
listxattr
llistxattr
lremovexattr
lsetxattr
removexattr
setxattr
fgetxattr
¶Documentation:
man fgetxattr
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
offset
and options
parameters:
macOS 11.1.
flistxattr
¶Documentation:
man flistxattr
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
fremovexattr
¶Documentation:
man fremovexattr
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
fsetxattr
¶Documentation:
man fsetxattr
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getxattr
¶Documentation:
man getxattr
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
offset
and options
parameters:
macOS 11.1.
lgetxattr
¶Documentation:
man lgetxattr
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
listxattr
¶Documentation:
man listxattr
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
llistxattr
¶Documentation:
man llistxattr
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
lremovexattr
¶Documentation:
man lremovexattr
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
lsetxattr
¶Documentation:
man lsetxattr
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
removexattr
¶Documentation:
man removexattr
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
setxattr
¶Documentation:
man setxattr
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<termios.h>
¶cfmakeraw
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-cfmakeraw-3.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
cfsetspeed
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-cfsetspeed-3.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<time.h>
¶clock_adjtime
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
dysize
¶Documentation:
man dysize
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getdate_r
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
stime
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-stime-2.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
strptime_l
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
timelocal
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
timespec_get
¶ISO C23 specification:
http://www.open-std.org/jtc1/sc22/wg14/www/docs/n3047.pdf section 7.29.2.6
Gnulib module: timespec_get
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<ttyent.h>
¶endttyent
¶Documentation:
man endttyent
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getttyent
¶Documentation:
man getttyent
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getttynam
¶Documentation:
man getttynam
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
setttyent
¶Documentation:
man setttyent
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<unistd.h>
¶_Fork
acct
brk
chroot
closefrom
copy_file_range
daemon
dup3
eaccess
endusershell
euidaccess
execveat
execvpe
get_current_dir_name
getdomainname
getdtablesize
getpagesize
getpass
getresgid
getresuid
gettid
getusershell
group_member
pipe2
profil
revoke
sbrk
setlogin
setdomainname
sethostid
sethostname
setresgid
setresuid
setusershell
syncfs
syscall
ttyslot
vhangup
_Fork
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/Creating-a-Process.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
acct
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-acct-3.html
Documentation:
man acct
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
brk
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
chroot
¶Documentation:
man chroot
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
closefrom
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/Opening-and-Closing-Files.html
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
Note (quoted from
man close):
“The [POSIX] standard developers rejected a proposal to add
closefrom()
to the [POSIX] standard. Because the standard
permits implementations to use inherited file descriptors as a means of
providing a conforming environment for the child process, it is not
possible to standardize an interface that closes arbitrary file
descriptors above a certain value while still guaranteeing a conforming
environment.”
copy_file_range
¶Documentation:
Gnulib module: copy-file-range
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
daemon
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-daemon-3.html
Documentation:
man daemon
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
dup3
¶Documentation:
man dup3
Gnulib module: dup3
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
eaccess
¶Documentation:
man eaccess
This function is an alias of euidaccess
. See euidaccess
.
endusershell
¶Documentation:
man endusershell
Gnulib module: getusershell
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
euidaccess
¶Documentation:
man euidaccess
Gnulib module: euidaccess
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
Other problems of this function:
stat
versus lstat
). If you need this option, use
the Gnulib module faccessat
with the AT_EACCESS
flag.
execveat
¶Documentation: man execveat.
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
execvpe
¶Documentation:
man execvpe
Gnulib module: execvpe
Portability problems fixed by Gnulib:
intptr_t
, not int
.
Portability problems not fixed by Gnulib:
get_current_dir_name
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getdomainname
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-getdomainname.html
Documentation:
Gnulib module: getdomainname
Portability problems fixed by Gnulib:
netdb.h
, not in unistd.h
, on
some platforms:
AIX 7.1.
int
, not size_t
, on some platforms:
macOS 11.1, FreeBSD 13.0, AIX 7.1, IRIX 6.5.
Portability problems not fixed by Gnulib:
getdtablesize
¶SUSv2 specification: https://pubs.opengroup.org/onlinepubs/7908799/xsh/getdtablesize.html
LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-getdtablesize.html
Documentation:
man getdtablesize
Gnulib module: getdtablesize
Portability problems fixed by Gnulib:
RLIMIT_NOFILE
soft
limit on some platforms:
Android 13 (LP32?), Cygwin 1.7.25.
Portability problems not fixed by Gnulib:
getpagesize
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-getpagesize.html
Documentation:
Gnulib module: getpagesize
Portability problems fixed by Gnulib:
-D_XOPEN_SOURCE=600
.
Portability problems not fixed by Gnulib:
getpass
¶Documentation:
Gnulib module: getpass or getpass-gnu
Portability problems fixed by either Gnulib module getpass
or getpass-gnu
:
Portability problems fixed by Gnulib module getpass-gnu
:
Portability problems not fixed by Gnulib:
getresgid
¶Future POSIX specification:
https://www.austingroupbugs.net/view.php?id=1344
Documentation:
man getresgid
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getresuid
¶Future POSIX specification:
https://www.austingroupbugs.net/view.php?id=1344
Documentation:
man getresuid
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
gettid
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getusershell
¶Documentation:
man getusershell
Gnulib module: getusershell
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
group_member
¶Documentation:
man group_member
Gnulib module: group-member
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pipe2
¶Documentation:
man pipe2
Gnulib module: pipe2
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
EMFILE
if no
resources are left on some platforms:
Cygwin 1.7.9.
Note: This function portably supports the O_NONBLOCK
flag only if the
gnulib module nonblocking
is also used.
profil
¶Documentation:
man profil
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
revoke
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
sbrk
¶Documentation:
man sbrk
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
setlogin
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
setdomainname
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
sethostid
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
sethostname
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-sethostname-2.html
Documentation:
Gnulib module: sethostname
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
char *
instead of const char *
on some platforms:
Solaris 11 2010-11.
int
instead of size_t
on some platforms:
macOS 11.1, MidnightBSD 2.0, Solaris 11 2010-11.
setresgid
¶Future POSIX specification:
https://www.austingroupbugs.net/view.php?id=1344
Documentation:
man setresgid
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
setresuid
¶Future POSIX specification:
https://www.austingroupbugs.net/view.php?id=1344
Documentation:
man setresuid
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
setusershell
¶Documentation:
man setusershell
Gnulib module: getusershell
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
syncfs
¶Documentation:
man syncfs
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
syscall
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
ttyslot
¶Documentation:
man ttyslot
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
vhangup
¶Documentation:
man vhangup
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<utmp.h>
¶endutent
getutent
getutent_r
getutid
getutid_r
getutline
getutline_r
pututline
setutent
updwtmp
utmpname
login
login_tty
endutent
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-endutent-3.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getutent
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-getutent-3.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getutent_r
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-getutent-r-3.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getutid
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getutid_r
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getutline
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
getutline_r
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
pututline
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
setutent
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-setutent-3.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
updwtmp
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
utmpname
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-utmpname-3.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
login
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
login_tty
¶Documentation:
Gnulib module: login_tty
Portability problems fixed by Gnulib:
<utmp.h>
on glibc, Cygwin, Android,
in <util.h>
on macOS 11.1, NetBSD 5.0, OpenBSD 3.8,
in <libutil.h>
on FreeBSD 13.0, Haiku,
and in <termios.h>
on Solaris 11.4.
-lutil
on some platforms:
glibc 2.3.6, FreeBSD 13.0, NetBSD 5.0, OpenBSD 3.8.
It is available without link options on other platforms:
macOS 11.1, Cygwin.
Portability problems not fixed by Gnulib:
<utmpx.h>
¶getutmp
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
time_t
was historically 32 bits.
year2038
or
year2038-recommended
modules are used and the program is
configured without the --disable-year2038 option.
The readutmp
module works around this problem:
glibc 2.38 on 32-bit platforms like x86 and ARM where time_t
was historically 32 bits.
See Avoiding the year 2038 problem.
getutmpx
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
time_t
was historically 32 bits.
year2038
or
year2038-recommended
modules are used and the program is
configured without the --disable-year2038 option.
The readutmp
module works around this problem:
glibc 2.38 on 32-bit platforms like x86 and ARM where time_t
was historically 32 bits.
See Avoiding the year 2038 problem.
updwtmpx
¶Documentation:
man updwtmpx
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
utmpxname
¶Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
<wchar.h>
¶fgetwc_unlocked
fgetws_unlocked
fputwc_unlocked
fputws_unlocked
getwc_unlocked
getwchar_unlocked
putwc_unlocked
putwchar_unlocked
wcschrnul
wcsftime_l
wcstod_l
wcstof_l
wcstol_l
wcstold_l
wcstoll_l
wcstoq
wcstoul_l
wcstoull_l
wcstouq
wmempcpy
fgetwc_unlocked
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-fgetwc-unlocked-1.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
fgetws_unlocked
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-fgetws-unlocked-1.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
fputwc_unlocked
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-fputwc-unlocked-1.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
fputws_unlocked
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-fputws-unlocked-1.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
getwc_unlocked
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-getwc-unlocked-1.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
getwchar_unlocked
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-getwchar-unlocked-1.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
putwc_unlocked
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-putwc-unlocked-1.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
putwchar_unlocked
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-putwchar-unlocked-1.html
Documentation:
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
wcschrnul
¶Documentation:
https://www.gnu.org/software/libc/manual/html_node/Search-Functions.html.
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
wcsftime_l
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
wcstod_l
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
wcstof_l
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
wcstol_l
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
wcstold_l
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
wcstoll_l
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
wcstoq
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-wcstoq.html
Documentation:
https://www.gnu.org/software/libc/manual/html_node/Parsing-of-Integers.html.
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
wcstoul_l
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
wcstoull_l
¶Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
wcstouq
¶LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-wcstouq.html
Documentation:
https://www.gnu.org/software/libc/manual/html_node/Parsing-of-Integers.html.
Gnulib module: —
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
wmempcpy
¶Documentation:
Gnulib module: wmempcpy
Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
wchar_t
is a 16-bit type and therefore cannot
accommodate all Unicode characters.
There are three ways to create binaries that run on Microsoft Windows:
This chapter deals with the MinGW and MSVC platforms, commonly called “native Windows” platforms. Cygwin, on the other hand, is close enough to POSIX that it can be treated like any other Unix-like platform.
If you want it to be possible to compile your program for a native Windows
platform and you use Libtool, you need to use the win32-dll
option of
LT_INIT
. In other words, put:
LT_INIT([win32-dll])
in your configure.ac. This sets the correct names for the
OBJDUMP
, DLLTOOL
, and AS
tools for the build.
If you are building a library, you will also need to pass
-no-undefined
to make sure Libtool produces a DLL for your
library. From a Makefile.am:
libgsasl_la_LDFLAGS += -no-undefined
This module provides support for files 2 GiB and larger, or with
device or inode numbers exceeding 32 bits.
To this effect, it attempts to ensure that types like off_t
and
ino_t
are 64-bit,
at least on the following platforms:
glibc, Mac OS X, FreeBSD, NetBSD, OpenBSD, AIX, HP-UX, IRIX, Solaris,
Cygwin, mingw, MSVC.
If the types cannot be made 64-bit, configure
issues a
warning and proceeds.
This module gives
configure
an option ‘--disable-largefile’ that
suppresses support for large files. This may be useful if the package
links to other libraries whose user-facing ABIs still require
off_t
or most other file-related types to be 32-bit on your
platform.
This module also adds to configure
an option
--enable-year2038
, needed on some platforms to access files
with timestamps past the year 2038. See Avoiding the year 2038 problem.
The module ‘windows-stat-inodes’ ensures that,
on native Windows platforms, struct stat
contains
st_dev
, st_ino
fields that are able to distinguish
different inodes.
Note: Such values can only be provided for most files on the
file system. For a few files (such as inaccessible files),
st_dev
and st_ino
are set to 0. Therefore,
you should test whether st_dev != 0 && st_ino != 0
,
before going to make inferences based on the file identity
based on st_dev
and st_ino
.
The module ‘windows-stat-timespec’ ensures that,
on native Windows platforms, struct stat
contains
st_atim
, st_mtim
, st_ctim
fields of type
struct timespec
, providing 100 ns resolution for the timestamps
of files.
Note: On some types of file systems, the timestamp resolution is limited
by the file system. For example, on FAT file systems, st_mtim
only has a resolution of 2 seconds. For more details, see
https://docs.microsoft.com/en-us/windows/desktop/SysInfo/file-times.
The year 2038 problem denotes unpredictable behaviour that will likely occur in the year 2038, for programs that use a 32-bit signed integer ‘time_t’ type that cannot represent timestamps on or after 2038-01-19 03:14:08 UTC. See Year 2038 problem for details.
The Gnulib module ‘year2038’ fixes this problem on some
platforms, by making time_t
wide enough to represent timestamps
after 2038. This has no effect on most current platforms, which have
timestamps that are already wide enough. However, ‘year2038’ by
default arranges for builds on legacy 32-bit Linux kernels running
glibc 2.34 and later to compile with ‘_TIME_BITS=64’ to get wider
timestamps. On older platforms that do not support timestamps after
the year 2038, ‘year2038’ causes configure
to issue a
warning but still proceed. On platforms that appear to support
post-2038 timestamps but where something prevents this from working,
configure
fails.
The default behavior of ‘year2038’ can be overridden by using the
configure
option --disable-year2038, which
suppresses support for post-2038 timestamps. This may be useful if
the package links to other libraries whose user-facing ABIs still
require time_t
to be 32-bit on your platform.
The Gnulib module ‘year2038-recommended’ is like ‘year2038’,
except it by default rejects platforms where time_t
cannot represent
timestamps after 2038. If this module is used and a 32-platform cannot support
64-bit time_t
, one can still fix the year-2038 problem by using
a 64-bit instead of a 32-bit build, as noted in the architecture list
below. If all else fails one can configure with
--disable-year2038; however, the resulting programs will
mishandle timestamps after 2038.
The Gnulib module ‘year2038-recommended’ is designed for packages intended for use on 32-bit platforms after the year 2038. If your package is commonly built on 32-bit platforms that will not be used after the year 2038, you can use the ‘year2038’ module instead, to save builders the trouble of configuring with --disable-year2038.
If the Gnulib module ‘largefile’ is used but neither
‘year2038’ nor ‘year2038-recommended’ is used,
configure
will have an option --enable-year2038
that causes configure
to behave as if ‘year2038’ was used.
This is for packages that have long used ‘largefile’ but have not
gotten around to upgrading their Gnulib module list to include
‘year2038’ or ‘year2038-recommended’.
See Large File Support.
With the ‘year2038-recommended’ module, configure
by
default should work on the following 32-bit platforms (or 32-bit ABIs
in bi-arch systems):
Whereas with ‘year2038-recommended’, configure
should
by default fail on earlier versions of the abovementioned platforms if
a version is listed, and it should also by default fail on all
versions of the following older 32-bit platforms or ABIs:
time_t
),
If you use the ‘year2038’ or ‘year2038-recommended’ modules,
and configure to support timestamps after the year 2038,
your code should not include ‘<utmp.h>’ or ‘<utmpx.h>’
directly, because these include files do not work with 64-bit timestamps
if the platform’s time_t
was traditionally 32 bits.
Your code can instead use the ‘readutmp’ module,
which works around this problem.
One of the portability problems for native Windows are sockets and networking functions.
This was written for the getaddrinfo
module, but may be applicable to
other functions too.
The getaddrinfo
function exists in ws2tcpip.h
and -lws2_32
on Windows XP. The function declaration is present if WINVER >= 0x0501
.
Windows 2000 does not have getaddrinfo
in its WS2_32.DLL.
Thus, if you want to assume Windows XP or later, you can add
AC_DEFINE([WINVER], [0x0501])
to avoid compiling the (partial)
getaddrinfo
implementation.
If you want to support Windows 2000, don’t do anything. The
replacement function will open WS2_32.DLL during run-time to
see if there is a getaddrinfo
function available, and use it when
available.
If your package does not desire to have MSVC support, that is, if MinGW
shall be the only native Windows platform that you wish to get support
for from Gnulib, and you wish to minimize the number of files imported
from Gnulib accordingly, you can do so by passing the options
‘--avoid=msvc-inval --avoid=msvc-nothrow’ to gnulib-tool
.
The lib-msvc-compat
module detects whether the linker supports
--output-def
when building a library. That parameter is used
to generate a DEF file for a shared library (DLL). DEF files are
useful for developers that use Visual Studio to develop programs that
links to your library. See the GNU LD manual for more information.
There are other ways to create a DEF file, but we believe they are all
sub-optimal to using --output-def
during the build process.
The variants we have considered include:
$ { echo EXPORTS; \ dumpbin /EXPORTS libfoo-0.dll | tail -n+20 | awk '{ print $4 }'; \ } > libfoo-0.def $ lib /def:libfoo-0.def
If you are using libtool to build your shared library, here is how to
use this module. Import lib-msvc-compat
to your project, and
then add the following lines to the Makefile.am
that builds the
library:
if HAVE_LD_OUTPUT_DEF libfoo_la_LDFLAGS += -Wl,--output-def,libfoo-$(DLL_VERSION).def libfoo-$(DLL_VERSION).def: libfoo.la defexecdir = $(libdir) defexec_DATA = libfoo-$(DLL_VERSION).def DISTCLEANFILES += $(defexec_DATA) endif
The DLL_VERSION
variable needs to be defined. It should be the
shared library version number used in the DLL filename. For Windows
targets you compute this value from the values you pass to Libtool’s
-version-info
. Assuming you have variables LT_CURRENT
and LT_AGE
defined for the CURRENT
and AGE
libtool version integers, you compute DLL_VERSION
as follows:
DLL_VERSION=`expr ${LT_CURRENT} - ${LT_AGE}` AC_SUBST(DLL_VERSION)
Multithreading is a programming paradigm. In a multithreaded program, multiple threads execute concurrently (or quasi concurrently) at different places in the program.
There are three motivations for using multithreading in a program:
select
or poll
on all the descriptors and then dispatches
according to from which descriptor input arrived. In a multi-threaded
program, you allocate one thread for each descriptor, and these threads can
be programmed and managed independently.
malloc
; therefore you are very limited in what you can do in
a signal handler. But a signal handler can notify a thread, and the thread
can then do the appropriate processing, as complex as it needs to be.
A multithreading API offers
Note: Programs that achieve multithreading through OpenMP (cf. the gnulib module ‘openmp’) don’t create and manage their threads themselves. Nevertheless, they need to use mutexes/locks in many cases.
Three multithreading APIs are available to Gnulib users:
They are supported on all platforms that have multithreading in one form or the other. Currently, these are all platforms supported by Gnulib, except for Minix.
The main differences are:
int
in the ISO C API.
Here are guidelines for determining which multithreading API is best for your code.
In programs that use advanced POSIX APIs, such as spin locks,
detached threads (pthread_detach
),
signal blocking (pthread_sigmask
),
priorities (pthread_setschedparam
),
processor affinity (pthread_setaffinity_np
), it is best to use
the POSIX API. This is because you cannot convert an ISO C thrd_t
or a Gnulib gl_thread_t
to a POSIX pthread_t
.
In code that is shared with glibc, it is best to use the POSIX API as well.
In libraries, it is best to use the Gnulib API. This is because it gives the person who builds the library an option ‘--enable-threads={isoc,posix,windows}’, that determines on which native multithreading API of the platform to rely. In other words, with this choice, you can minimize the amount of glue code that your library needs to contain.
In the other cases, the POSIX API and the Gnulib API are equally well suited.
The ISO C API is never the best choice, as of this writing (2020).
The POSIX multithreading API is documented in POSIX https://pubs.opengroup.org/onlinepubs/9699919799/.
To make use of POSIX multithreading, even on platforms that don’t support it natively (most prominently, native Windows), use the following Gnulib modules:
Purpose | Module |
---|---|
For thread creation and management: | pthread-thread |
For simple and recursive locks: | pthread-mutex |
For read-write locks: | pthread-rwlock |
For once-only execution: | pthread-once |
For “condition variables” (wait queues): | pthread-cond |
For thread-local storage: | pthread-tss |
For relinquishing control: | sched_yield |
For spin locks: | pthread-spin |
There is also a convenience module named pthread
which depends on all
of these (except sched_yield
); so you don’t need to enumerate these
modules one by one.
The ISO C multithreading API is documented in ISO C 11 http://www.open-std.org/jtc1/sc22/wg14/www/docs/n1570.pdf.
To make use of ISO C multithreading, even on platforms that don’t support it or have severe bugs, use the following Gnulib modules:
Purpose | Module |
---|---|
For thread creation and management: | thrd |
For simple locks, recursive locks, and read-write locks: | mtx |
For once-only execution: | mtx |
For “condition variables” (wait queues): | cnd |
For thread-local storage: | tss |
There is also a convenience module named threads
which depends on all
of these; so you don’t need to enumerate these modules one by one.
The Gnulib multithreading API is documented in the respective include files:
<glthread/thread.h>
<glthread/lock.h>
<glthread/cond.h>
<glthread/tls.h>
<glthread/yield.h>
To make use of Gnulib multithreading, use the following Gnulib modules:
Purpose | Module |
---|---|
For thread creation and management: | thread |
For simple locks, recursive locks, and read-write locks: | lock |
For once-only execution: | lock |
For “condition variables” (wait queues): | cond |
For thread-local storage: | tls |
For relinquishing control: | yield |
The Gnulib multithreading supports a configure option ‘--enable-threads={isoc,posix,windows}’, that chooses the underlying thread implementation. Currently (2020):
--enable-threads=posix
is supported and is the best choice on all
platforms except for native Windows. It may also work, to a limited extent,
on mingw with the winpthreads
library, but is not recommended there.
--enable-threads=windows
is supported and is the best choice on
native Windows platforms (mingw and MSVC).
--enable-threads=isoc
is supported on all platforms that have the
ISO C multithreading API. However, --enable-threads=posix
is always
a better choice.
Despite all the optimizations of multithreading primitives that have been implemented over the years – from atomic operations in hardware, over futexes and restartable sequences in the Linux kernel, to lock elision [1] [2]) – single-threaded programs can still profit performance-wise from the assertion that they are single-threaded.
Gnulib defines four facilities that help optimizing for the single-threaded case.
libpthread
. If not, the program has no way to create additional
threads and must therefore be single-threaded. This optimization applies
to all the Gnulib multithreading API (locks, thread-local storage, and more).
thread-optim
module, on glibc ≥ 2.32 systems, allows your code
to skip locking between threads (regardless which of the three multithreading
APIs you use). You need extra code for this: include the
"thread-optim.h"
header file, and use the macro gl_multithreaded
like this:
bool mt = gl_multithreaded (); if (mt) gl_lock_lock (some_lock); ... if (mt) gl_lock_unlock (some_lock);
unlocked-io
module if you want the FILE
stream
functions getc
, putc
, etc. to use unlocked I/O if available,
throughout the package. Unlocked I/O can improve performance, sometimes
dramatically. But unlocked I/O is safe only in single-threaded programs,
as well as in multithreaded programs for which you can guarantee that
every FILE
stream, including stdin
, stdout
, stderr
,
is used only in a single thread.
You need extra code for this optimization to be effective: include the
"unlocked-io.h"
header file. Some Gnulib modules that do operations
on FILE
streams have these preparations already included.
GNULIB_REGEX_SINGLE_THREAD
, if all the
programs in your package invoke the functions of the regex
module
only from a single thread.
GNULIB_MBRTOWC_SINGLE_THREAD
, if all the
programs in your package invoke the functions mbrtowc
, mbrtoc32
,
and the functions of the regex
module only from a single thread. (The
regex
module uses mbrtowc
under the hood.)
GNULIB_WCHAR_SINGLE_LOCALE
, if all the
programs in your package set the locale early and
mbrtowc
, wcwidth
, etc.)
before the locale has been initialized.
This macro optimizes the functions mbrtowc
, mbrtoc32
, and
wcwidth
.
You can get this macro defined by including the Gnulib module
wchar-single
.
GNULIB_GETUSERSHELL_SINGLE_THREAD
, if all the
programs in your package invoke the functions setusershell
,
getusershell
, endusershell
only from a single thread.
GNULIB_EXCLUDE_SINGLE_THREAD
, if all the
programs in your package invoke the functions of the exclude
module
only from a single thread.
This chapter describes the APIs for strings and characters, provided by Gnulib.
Several possible representations exist for the representation of strings in memory of a running C program.
The classical representation of a string in C is a sequence of
characters, where each character takes up one or more bytes, followed by
a terminating NUL byte. This representation is used for strings that
are passed by the operating system (in the argv
argument of
main
, for example) and for strings that are passed to the
operating system (in system calls such as open
). The C type to
hold such strings is ‘char *’ or, in places where the string shall
not be modified, ‘const char *’. There are many C library
functions, standardized by ISO C and POSIX, that assume this
representation of strings.
A character encoding, or encoding for short, describes
how the elements of a character set are represented as a sequence of
bytes. For example, in the ASCII
encoding, the UNDERSCORE
character is represented by a single byte, with value 0x5F. As another
example, the COPYRIGHT SIGN character is represented:
ISO-8859-1
encoding, by the single byte 0xA9,
UTF-8
encoding, by the two bytes 0xC2 0xA9,
GB18030
encoding, by the four bytes 0x81 0x30 0x84 0x38.
Note: The ‘char’ type may be signed or unsigned, depending on the
platform. When we talk about the "byte 0xA9" we actually mean the
char
object whose value is (char) 0xA9
; we omit the cast
to char
in this documentation, for brevity.
In POSIX, the character encoding is determined by the locale. The locale is some environmental attribute that the user can choose.
Depending on the encoding, in general, every character is represented by
one or more bytes (up to 4 bytes in practice – but
use MB_LEN_MAX
instead of the number 4 in the code).
When every character is represented by only 1 byte, we speak of an
“unibyte locale”, otherwise of a “multibyte locale”.
It is important to realize that the majority of Unix installations nowadays use UTF-8 as locale encoding; therefore, the majority of users are using multibyte locales.
Three important facts to remember are:
A ‘char’ is a byte, not a character. |
As a consequence:
<ctype.h>
API, that was designed only with unibyte
encodings in mind, is useless nowadays for general text processing; it
does not work in multibyte locales.
strlen
function does not return the number of characters
in a string. Nor does it return the number of screen columns occupied
by a string after it is output. It merely returns the number of
bytes occupied by a string.
strncpy
, can have the
effect of truncating it in the middle of a multibyte character. Such
a string will, when output, have a garbled character at its end, often
represented by a hollow box.
Multibyte does not imply UTF-8 encoding. |
While UTF-8 is the most common multibyte encoding, GB18030 is also a supported locale encoding on GNU systems (mostly because it is a Chinese government standard, last revised in 2022).
Searching for a character in a string is not the same as searching for a byte in the string. |
Take the above example of COPYRIGHT SIGN in the GB18030
encoding:
A byte search will find the bytes '0'
and '8'
in this
string. But a search for the character "0" or "8" in the string
"©" must, of course, report “not found”.
As a consequence:
strchr
and strrchr
do not work with multibyte
strings if the locale encoding is GB18030 and the character to be
searched is a digit.
strstr
does not work with multibyte strings if the locale
encoding is different from UTF-8.
strcspn
, strpbrk
, strspn
cannot work
correctly in multibyte locales: they assume the second argument is a
list of single-byte characters. Even in this simple case, they do not
work with multibyte strings if the locale encoding is GB18030 and one of
the characters to be searched is a digit.
strsep
and strtok_r
do not work with multibyte
strings unless all of the delimiter characters are ASCII characters
< 0x30.
strcasecmp
, strncasecmp
, and
strcasestr
functions do not work with multibyte strings.
Workarounds can be found in Gnulib, in the form of mbs*
API
functions:
mbslen
and mbswidth
that can be used
instead of strlen
when the number of characters or the
number of screen columns of a string is requested.
mbschr
and mbsrrchr
that are like
strchr
and strrchr
, but work in multibyte
locales.
mbsstr
that is like strstr
, but
works in multibyte locales.
mbscspn
, mbspbrk
, mbsspn
that
are like strcspn
, strpbrk
, strspn
,
but work in multibyte locales.
mbssep
and mbstok_r
that are like
strsep
and strtok_r
but work in multibyte
locales.
mbscasecmp
, mbsncasecmp
,
mbspcasecmp
, and mbscasestr
that are like
strcasecmp
, strncasecmp
, and
strcasestr
, but work in multibyte locales. Still, the
function ulc_casecmp
is preferable to these functions.
A C string can contain encoding errors. |
Not every NUL-terminated byte sequence represents a valid multibyte string. Byte sequences can contain encoding errors, that is, bytes or byte sequences that are invalid and do not represent characters.
String functions like mbscasecmp
and strcoll
whose
behavior depends on encoding have unspecified behavior on strings
containing encoding errors, unless the behavior is specifically
documented. If an application needs a particular behavior on these
strings it can iterate through them itself, as described in the next
subsection.
For complex string processing, string functions may not be enough, and you need to iterate through a string while processing each (possibly multibyte) character or encoding error in turn. Gnulib has several modules for iterating forward through a string in this way. Backward iteration, that is, from the string’s end to start, is not provided, as it is too hairy in general.
mbiter
module iterates through a string whose length
is already known. The string can contain NULs and encoding errors.
mbiterf
module is like mbiter
except it is more complex and typically faster.
mbuiter
module iterates through a C string whose length
is not a-priori known. The string can contain encoding errors and is
terminated by the first NUL.
mbuiterf
module is like mbuiter
except it is more complex and typically faster.
mcel
module is simpler than mbiter
and mbuiter
and can be faster than even mbiterf
and mbuiterf
.
It can iterate through either strings whose length is known, or
C strings, or strings terminated by other ASCII characters < 0x30.
mcel-prefer
module is like mcel
except that it
causes some other modules to be based on mcel
instead of
on the mbiter
family.
The choice of modules depends on the application’s needs. The
mbiter
module family is more suitable for applications that
treat some sequences of two or more bytes as a single encoding error,
and for applications that need to support obsolescent encodings on
non-GNU platforms, such as CP864, EBCDIC, Johab, and Shift JIS.
In this module family, mbuiter
and mbuiterf
are more
suitable than mbiter
and mbiterf
when arguments are C strings,
lengths are not already known, and it is highly likely that only the
first few multibyte characters need to be inspected.
The mcel
module is simpler and can be faster than the
mbiter
family, and is more suitable for applications that do
not need the mbiter
family’s special features.
The mcel-prefer
module is like mcel
except that it also
causes some other modules, such as mbscasecmp
, to use
mcel
rather than the mbiter
family. This can be simpler
and faster. However, it does not support the obsolescent encodings,
and it may behave differently on data containing encoding errors where
behavior is unspecified or undefined, because in mcel
each
encoding error is a single byte whereas in the mbiter
family a
single encoding error can contain two or more bytes.
If a package uses mcel-prefer
, it may also want to give
gnulib-tool
one or more of the options
--avoid=mbiter, --avoid=mbiterf,
--avoid=mbuiter and --avoid=mbuiterf,
to avoid packaging modules that are not needed.
The GNU Coding Standards, section https://www.gnu.org/prep/standards/html_node/Semantics.html, specifies:
Utilities reading files should not drop NUL characters, or any other nonprinting characters. |
When it is a requirement to store NUL characters in strings, a variant of the C strings is needed. Gnulib offers a “string descriptor” type for this purpose. See Handling strings with NUL characters.
All remarks regarding encodings and multibyte characters in the previous section apply to string descriptors as well.
The functions in this section are similar to the generic string functions from the standard C library, except that
The functions are provided by the following modules.
The c-ctype
module contains functions operating on single-byte
characters, like the functions in <ctype.h>
, that operate as if the
locale encoding was ASCII. (The "C" locale on many systems has the locale
encoding "ASCII".)
The functions are:
extern bool c_isascii (int c); extern bool c_isalnum (int c); extern bool c_isalpha (int c); extern bool c_isblank (int c); extern bool c_iscntrl (int c); extern bool c_isdigit (int c); extern bool c_islower (int c); extern bool c_isgraph (int c); extern bool c_isprint (int c); extern bool c_ispunct (int c); extern bool c_isspace (int c); extern bool c_isupper (int c); extern bool c_isxdigit (int c); extern int c_tolower (int c); extern int c_toupper (int c);
These functions assign properties only to ASCII characters.
The c argument can be a char
or unsigned char
value,
whereas the corresponding functions in <ctype.h>
take an argument
that is actually an unsigned char
value.
The c_is*
functions return ‘bool’, where the corresponding
functions in <ctype.h>
return ‘int’ for historical reasons.
Note: The <ctype.h>
functions support only unibyte locales.
The c-strcase
module contains case-insensitive string comparison
functions operating on single-byte character strings, like the functions in
<strings.h>
, that operate as if the locale encoding was ASCII.
(The "C" locale on many systems has the locale encoding "ASCII".)
The functions are:
extern int c_strcasecmp (const char *s1, const char *s2); extern int c_strncasecmp (const char *s1, const char *s2, size_t n);
For case conversion here, only ASCII characters are considered to be upper case or lower case.
Note: The functions strcasecmp
, strncasecmp
from
<strings.h>
support only unibyte locales; for multibyte locales,
you need the functions mbscasecmp
, mbsncasecmp
,
mbspcasecmp
.
The c-strcaseeq
module contains an optimized case-insensitive
string comparison function operating on single-byte character strings, that
operate as if the locale encoding was ASCII.
(The "C" locale on many systems has the locale encoding "ASCII".)
The functions is actually implemented as a macro:
extern int STRCASEEQ (const char *s1, const char *s2, int s20, int s21, int s22, int s23, int s24, int s25, int s26, int s27, int s28);
s2 should be a short literal ASCII string, and s20, s21, ... the individual characters of s2.
For case conversion here, only ASCII characters are considered to be upper case or lower case.
The c-strcasestr
module contains a case-insensitive string search
function operating on single-byte character strings, that operate as if the
locale encoding was ASCII.
(The "C" locale on many systems has the locale encoding "ASCII".)
The function is:
extern char *c_strcasestr (const char *haystack, const char *needle);
For case conversion here, only ASCII characters are considered to be upper case or lower case.
Note: The function strcasestr
from <string.h>
supports only
unibyte locales; for multibyte locales, you need the function
mbscasestr
.
The c-strstr
module contains a substring search function operating
on single-byte character strings, that operate as if the locale encoding
was ASCII.
(The "C" locale on many systems has the locale encoding "ASCII".)
The function is:
extern char *c_strstr (const char *haystack, const char *needle);
Note: The function strstr
from <string.h>
supports only
unibyte locales; for multibyte locales, you need the function
mbsstr
.
The c-strtod
module contains a string to number (‘double’)
conversion function operating on single-byte character strings, that operates
as if the locale encoding was ASCII.
(The "C" locale on many systems has the locale encoding "ASCII".)
The function is:
extern double c_strtod (const char *string, char **endp);
In particular, only a period ‘.’ is accepted as decimal point, even when the current locale’s notion of decimal point is a comma ‘,’, and no characters outside the basic character set are accepted.
On platforms without strtod_l
, this function is not safe for use in
multi-threaded applications since it calls setlocale
.
The c-strtold
module contains a string to number (‘long double’)
conversion function operating on single-byte character strings, that operates
as if the locale encoding was ASCII.
(The "C" locale on many systems has the locale encoding "ASCII".)
The function is:
extern long double c_strtold (const char *string, char **endp);
In particular, only a period ‘.’ is accepted as decimal point, even when the current locale’s notion of decimal point is a comma ‘,’.
This table summarizes the API functions available for strings, in POSIX and in Gnulib.
unibyte strings only | assume C locale | multibyte strings | multibyte strings with NULs | wide character strings | 32-bit wide character strings |
---|---|---|---|---|---|
strlen | strlen | mbslen | string_desc_length | wcslen | u32_strlen |
strnlen | strnlen | mbsnlen | – | wcsnlen | u32_strnlen , u32_mbsnlen |
strcmp | strcmp | strcmp | string_desc_cmp | wcscmp | u32_strcmp |
strncmp | strncmp | strncmp | – | wcsncmp | u32_strncmp |
strcasecmp | strcasecmp | mbscasecmp | – | wcscasecmp | u32_casecmp |
strncasecmp | strncasecmp | mbsncasecmp , mbspcasecmp | – | wcsncasecmp | u32_casecmp |
strcoll | strcmp | strcoll | – | wcscoll | u32_strcoll |
strxfrm | – | strxfrm | – | wcsxfrm | – |
strchr | strchr | mbschr | string_desc_index | wcschr | u32_strchr |
strrchr | strrchr | mbsrchr | string_desc_last_index | wcsrchr | u32_strrchr |
strstr | strstr | mbsstr | string_desc_contains | wcsstr | u32_strstr |
strcasestr | strcasestr | mbscasestr | – | – | – |
strspn | strspn | mbsspn | – | wcsspn | u32_strspn |
strcspn | strcspn | mbscspn | – | wcscspn | u32_strcspn |
strpbrk | strpbrk | mbspbrk | – | wcspbrk | u32_strpbrk |
strtok_r | strtok_r | mbstok_r | – | wcstok | u32_strtok |
strsep | strsep | mbssep | – | – | – |
strcpy | strcpy | strcpy | string_desc_copy | wcscpy | u32_strcpy |
stpcpy | stpcpy | stpcpy | – | wcpcpy | u32_stpcpy |
strncpy | strncpy | strncpy | – | wcsncpy | u32_strncpy |
stpncpy | stpncpy | stpncpy | – | wcpncpy | u32_stpncpy |
strcat | strcat | strcat | string_desc_concat | wcscat | u32_strcat |
strncat | strncat | strncat | – | wcsncat | u32_strncat |
free | free | free | string_desc_free | free | free |
strdup | strdup | strdup | string_desc_copy | wcsdup | u32_strdup |
strndup | strndup | strndup | – | – | – |
mbswidth | mbswidth | mbswidth | – | wcswidth | c32swidth , u32_strwidth |
strtol | strtol | strtol | – | – | – |
strtoul | strtoul | strtoul | – | – | – |
strtoll | strtoll | strtoll | – | – | – |
strtoull | strtoull | strtoull | – | – | – |
strtoimax | strtoimax | strtoimax | – | wcstoimax | – |
strtoumax | strtoumax | strtoumax | – | wcstoumax | – |
strtof | – | strtof | – | – | – |
strtod | c_strtod | strtod | – | – | – |
strtold | c_strtold | strtold | – | – | – |
strfromf | – | strfromf | – | – | – |
strfromd | – | strfromd | – | – | – |
strfroml | – | strfroml | – | – | – |
– | – | – | – | mbstowcs | mbstoc32s |
– | – | – | – | mbsrtowcs | mbsrtoc32s |
– | – | – | – | mbsnrtowcs | mbsnrtoc32s |
– | – | – | – | wcstombs | c32stombs |
– | – | – | – | wcsrtombs | c32srtombs |
– | – | – | – | wcsnrtombs | c32snrtombs |
A character is the elementary unit that strings are made of.
What is a character? “A character is an element of a character set” is sort of a circular definition, but it highlights the fact that it is not merely a number. Although many characters are visually represented by a single glyph, there are characters that, for example, have a different glyph when used at the end of a word than when used inside a word. A character is also not the minimal rendered text processing unit; that is a grapheme cluster and in general consists of one or more characters. If you want to know more about the concept of character and various concepts associated with characters, refer to the Unicode standard.
For the representation in memory of a character, various types have been
in use, and some of them were failures: char
and wchar_t
were invented for this purpose, but are not the right types.
char32_t
is the right type (successor of wchar_t
); and
mbchar_t
(defined by Gnulib) is an alternative for specific kinds
of processing.
char
type ¶The char
type is in the C language since the beginning in the
1970ies, but – due to its limitation of 256 possible values – is no
longer the adequate type for storing a character.
Technically, it is still adequate in unibyte locales. But since most locales nowadays are multibyte locales, it makes no sense to write a program that runs only in unibyte locales.
ISO C and POSIX standardized an API for characters of type char
,
in <ctype.h>
. This API is nowadays useless and obsolete, when it
comes to general text processing.
The important lessons to remember are:
A ‘char’ is just the elementary storage unit for a string, not a character. |
Never use |
wchar_t
type ¶The ISO C and POSIX standard creators made an attempt to overcome the
dead end regarding the char
type. They introduced
<wchar.h>
, and
<wctype.h>
that were meant to supplant
the ones in <ctype.h>
.
Unfortunately, this API and its implementation has numerous problems:
wchar_t
is a
16-bit type. This means that it can never accommodate an entire Unicode
character. Either the wchar_t *
strings are limited to
characters in UCS-2 (the “Basic Multilingual Plane” of Unicode), or
– if wchar_t *
strings are encoded in UTF-16 – a
wchar_t
represents only half of a character in the worst case,
making the <wctype.h>
functions pointless.
wchar_t
encoding is locale dependent
and undocumented. This means, if you want to know any property of a
wchar_t
character, other than the properties defined by
<wctype.h>
– such as whether it’s a dash, currency symbol,
paragraph separator, or similar –, you have to convert it to
char *
encoding first, by use of the function wctomb
.
fgetwc
and fgetws
, and when the input
stream/file is not in the expected encoding, you have no way to
determine the invalid byte sequence and do some corrective action. If
you use these functions, your program becomes “garbage in - more
garbage out” or “garbage in - abort”.
As a consequence, it is better to use multibyte strings. Such multibyte
strings can bypass limitations of the wchar_t
type, if you use
functions defined in Gnulib and GNU libunistring for text processing.
They can also faithfully transport malformed characters that were
present in the input, without requiring the program to produce garbage
or abort.
char32_t
type ¶The ISO C and POSIX standard creators then introduced the
char32_t
type. In ISO C 11, it was conceptually a “32-bit wide
character” type. In ISO C 23, its semantics has been further
specified: A char32_t
value is a Unicode code point.
Thus, the char32_t
type is not affected the problems that plague
the wchar_t
type.
The char32_t
type and its API are defined in the <uchar.h>
header file.
ISO C and POSIX specify only the basic functions for the char32_t
type, namely conversion of a single character (mbrtoc32
and
c32rtomb
). For convenience, Gnulib adds API for classification
and case conversion of characters.
GNU libunistring can also be used on char32_t
values. Since
char32_t
is the same as uint32_t
, all u32_*
functions of GNU libunistring are applicable to arrays of
char32_t
values.
On glibc systems, use of the 32-bit wide strings (char32_t[]
) is
exactly as efficient as the use of the older wide strings
(wchar_t[]
). This is possible because on glibc, wchar_t
values already always were 32-bit and Unicode code points.
mbrtoc32
is just an alias of mbrtowc
. The Gnulib
*c32*
functions are optimized so that on glibc systems they
immediately redirect to the corresponding *wc*
functions.
Gnulib implements the ISO C 23 semantics of char32_t
when you
import the ‘uchar-c23’ module. Without this module, it implements
only the ISO C 11 semantics; the effect is that on some platforms
(macOS, FreeBSD, NetBSD, Solaris) a char32_t
value is the same
as a wchar_t
value, not a Unicode code point. Thus, when you
want to pass char32_t
values to GNU libunistring or to some Unicode
centric Gnulib functions, you need the ‘uchar-c23’ module in order
to do so without portability problems.
mbchar_t
type ¶Gnulib defines an alternate way to encode a multibyte character:
mbchar_t
. Its main feature is the ability to process a string or
stream with some malformed characters without reporting an error.
The type mbchar_t
, defined in "mbchar.h"
, holds a
character in both the multibyte and the 32-bit wide character
representation. In case of a malformed character only the multibyte
representation is used.
If you want to process (possibly multibyte) characters while reading
them from a FILE *
stream, without reading them into a string
first, the mbfile
module is made for this purpose.
This table summarizes the API functions available for characters, in POSIX and in Gnulib.
unibyte character | assume C locale | wide character | 32-bit wide character | mbchar_t character |
---|---|---|---|---|
== '\0' | == '\0' | == L'\0' | == 0 | mb_isnul |
== | == | == | == | mb_equal |
isalnum | c_isalnum | iswalnum | c32isalnum | mb_isalnum |
isalpha | c_isalpha | iswalpha | c32isalpha | mb_isalpha |
isblank | c_isblank | iswblank | c32isblank | mb_isblank |
iscntrl | c_iscntrl | iswcntrl | c32iscntrl | mb_iscntrl |
isdigit | c_isdigit | iswdigit | c32isdigit | mb_isdigit |
isgraph | c_isgraph | iswgraph | c32isgraph | mb_isgraph |
islower | c_islower | iswlower | c32islower | mb_islower |
isprint | c_isprint | iswprint | c32isprint | mb_isprint |
ispunct | c_ispunct | iswpunct | c32ispunct | mb_ispunct |
isspace | c_isspace | iswspace | c32isspace | mb_isspace |
isupper | c_isupper | iswupper | c32isupper | mb_isupper |
isxdigit | c_isxdigit | iswxdigit | c32isxdigit | mb_isxdigit |
– | – | wctype | c32_get_type_test | – |
– | – | iswctype | c32_apply_type_test | – |
tolower | c_tolower | towlower | c32tolower | – |
toupper | c_toupper | towupper | c32toupper | – |
– | – | wctrans | c32_get_mapping | – |
– | – | towctrans | c32_apply_mapping | – |
– | – | wcwidth | c32width | mb_width |
The alloca
module provides for a function alloca
which allocates
memory on the stack, where the system allows it. A memory block allocated with
alloca
exists only until the function that calls alloca
returns
or exits abruptly.
There are a few systems where this is not possible: HP-UX systems, and some
other platforms when the C++ compiler is used. On these platforms the alloca
module provides a malloc
based emulation. This emulation will not free a
memory block immediately when the calling function returns, but rather will
wait until the next alloca
call from a function with the same or a
shorter stack length. Thus, in some cases, a few memory blocks will be kept
although they are not needed any more.
The user can #include <alloca.h>
and use alloca
on all platforms.
Note that the #include <alloca.h>
must be the first one after the
autoconf-generated config.h, for AIX 3 compatibility. Thanks to IBM for
this nice restriction!
Note that GCC 3.1 and 3.2 can inline functions that call alloca
.
When this happens, the memory blocks allocated with alloca
will not be
freed until the end of the calling function. If this calling function
runs a loop calling the function that uses alloca
, the program easily
gets a stack overflow and crashes. To protect against this compiler behaviour,
you can mark the function that uses alloca
with the following attribute:
#ifdef __GNUC__ __attribute__ ((__noinline__)) #endif
An alternative to this module is the ‘alloca-opt’ module.
The alloca-opt
module provides for a function alloca
which allocates
memory on the stack, where the system allows it. A memory block allocated with
alloca
exists only until the function that calls alloca
returns
or exits abruptly.
There are a few systems where this is not possible: HP-UX systems, and some
other platforms when the C++ compiler is used. On these platforms the
alloca-opt
module provides no replacement, just a preprocessor macro
HAVE_ALLOCA.
The user can #include <alloca.h>
on all platforms, and use
alloca
on those platforms where the preprocessor macro HAVE_ALLOCA
evaluates to true. If HAVE_ALLOCA is false, the code should use a heap-based
memory allocation based on malloc
or (in C++) new
. Note that
the #include <alloca.h>
must be the first one after the
autoconf-generated config.h, for AIX 3 compatibility. Thanks to IBM for
this nice restriction!
Note that GCC 3.1 and 3.2 can inline functions that call alloca
.
When this happens, the memory blocks allocated with alloca
will not be
freed until the end of the calling function. If this calling function
runs a loop calling the function that uses alloca
, the program easily
gets a stack overflow and crashes. To protect against this compiler behaviour,
you can mark the function that uses alloca
with the following attribute:
#ifdef __GNUC__ __attribute__ ((__noinline__)) #endif
The standard C library malloc/realloc/calloc/free APIs are prone to a
number of common coding errors. The safe-alloc
module provides
macros that make it easier to avoid many of them. It still uses the
standard C allocation functions behind the scenes.
Some of the memory allocation mistakes that are commonly made are
malloc
, especially
when allocating an array,
malloc
and realloc
for
errors,
malloc
,
free
by forgetting to set the pointer
variable to NULL
,
realloc
when that call fails.
The safe-alloc
module addresses these problems in the following way:
__warn_unused_result__
attribute.
calloc
instead of
malloc
so that the array’s contents are zeroed.
However, memory added to an already-existing array is uninitialized.
Allocate sizeof *ptr
bytes of memory and store the address of
allocated memory in ptr
. Fill the newly allocated memory with
zeros.
Returns −1 on failure, 0 on success.
Allocate an array of count
elements, each sizeof *ptr
bytes long, and store the address of allocated memory in
ptr
. Fill the newly allocated memory with zeros.
Returns −1 on failure, 0 on success.
Allocate an array of count
elements, each sizeof *ptr
bytes long, and store the address of allocated memory in
ptr
. The allocated memory is not initialized.
Returns −1 on failure, 0 on success.
Reallocate the memory pointed to by ptr
to be big enough to hold
at least count
elements, each sizeof *ptr
bytes long,
and store the address of allocated memory in ptr
. If
reallocation fails, the ptr
variable is not modified.
If the new array is smaller than the old one, discard excess contents;
if larger, the newly added storage is not initialized.
Returns −1 on failure, 0 on success.
Free the memory stored in ptr
and set ptr
to
NULL
.
This module provides a header file attribute.h that defines
macros related to C and C++ attributes and the GCC
__attribute__
keyword.
Here is an example of its use:
#include <attribute.h> NODISCARD extern char *crypt (char const *, char const *) ATTRIBUTE_NOTHROW ATTRIBUTE_LEAF ATTRIBUTE_NONNULL ((1, 2));
NODISCARD
expands to [[nodiscard]]
if the compiler
supports this C23 syntax, otherwise to
__attribute__ ((__warn_unused_result__))
if the compiler
is a recent-enough GCC or GCC-like compiler, otherwise to nothing.
ATTRIBUTE_NOTHROW
expands to __attribute__
((__nothrow__))
if the compiler is a recent-enough GCC or GCC-like
compiler, and to nothing otherwise. Similarly for
ATTRIBUTE_LEAF
. ATTRIBUTE_NONNULL ((1, 2))
expands to
__attribute__ ((__nonnull__ (1, 2)))
if the compiler is
recent-enough GCC, and to nothing otherwise.
Most of these attribute names begin with ATTRIBUTE_
.
A few do not, because they are part of C23 and their
names are not likely to clash with other macro names.
These macros are DEPRECATED
, FALLTHROUGH
,
MAYBE_UNUSED
, and NODISCARD
, which can
be defined to [[deprecated]]
etc. on C23 platforms.
Also, these exceptional macros should be placed at the start of
function declarations, whereas the ATTRIBUTE_*
macros can be
placed at the end.
This module provides a header file verify.h that defines macros related to compile-time verification.
Two of these macros are verify (V)
and verify_expr
(V, EXPR)
. Both accept an integer constant expression
argument V and verify that it is nonzero. If not, a compile-time error
results.
These two macros implement compile-time tests, as opposed to
the standard assert
macro which supports only runtime tests.
Since the tests occur at compile-time, they are more reliable, and
they require no runtime overhead.
verify (V);
is a declaration; it can occur outside of
functions. In contrast, verify_expr (V, EXPR)
is
an expression that returns the value of EXPR; it can be used in
macros that expand to expressions. If EXPR is an integer
constant expression, then verify_expr (V, EXPR)
is
also an integer constant expression. Although EXPR and
verify_expr (V, EXPR)
are guaranteed to have the
same side effects and value and type (after integer promotion), they
need not have the same type if EXPR’s type is an integer that is
narrower than int
or unsigned int
.
V should be an integer constant expression in the sense
of the C standard. Its leaf operands should be integer, enumeration,
or character constants; or sizeof
expressions that return
constants; or floating constants that are the immediate operands of
casts. Outside a sizeof
subexpression, V should
not contain any assignments, function calls, comma operators, casts to
non-integer types, or subexpressions whose values are outside the
representable ranges for their types. If V is not an
integer constant expression, then a compiler might reject a usage like
‘verify (V);’ even when V is
nonzero.
Although the standard assert
macro is a runtime test, C23 and C++17
specify a builtin static_assert (V)
, which differs
from verify
in two major ways. First, it can also be used
within a struct
or union
specifier, in place of an
ordinary member declaration. Second, it allows the programmer to
specify, as an optional second argument, a compile-time diagnostic as
a string literal. If your program is not intended to be portable to
compilers that lack C23 or C++17 static_assert
, the only
advantage of verify
is that its name is a bit shorter.
The verify.h header defines one more macro, assume
(E)
, which expands to an expression of type void
that causes the compiler to assume that E yields a nonzero
value. E should be a scalar expression, and should not
have side effects; it may or may not be evaluated. The behavior is
undefined if E would yield zero. The main use of assume
is optimization, as the compiler may be able to generate better code
if it assumes E. For best results, E should be simple
enough that a compiler can determine that it has no side effects: if
E calls an external function or accesses volatile storage the
compiler may not be able to optimize E away and assume
(E)
may therefore slow down the program.
Here are some example uses of these macros.
#include <verify.h> #include <limits.h> #include <time.h> /* Verify that time_t is an integer type. */ verify ((time_t) 1.5 == 1); /* Verify that time_t is no smaller than int. */ verify (sizeof (int) <= sizeof (time_t)); /* Verify that time_t is signed. */ verify ((time_t) -1 < 0); /* Verify that time_t uses two's complement representation. */ verify (~ (time_t) -1 == 0); /* Return the maximum value of the integer type T, verifying that T is an unsigned integer type. The cast to (T) is outside the call to verify_expr so that the result is of type T even when T is narrower than unsigned int. */ #define MAX_UNSIGNED_VAL(t) \ ((T) verify_expr (0 < (T) -1, -1)) /* Return T divided by CHAR_MAX + 1, where behavior is undefined if T < 0. In the common case where CHAR_MAX is 127 the compiler can therefore implement the division by shifting T right 7 bits, an optimization that would not be valid if T were negative. */ time_t time_index (time_t t) { assume (0 <= t); return t / (CHAR_MAX + 1); }
A "non-returning" function is a function which cannot return normally.
Instead of returning, it can loop forever, or it can transfer control via
abort
, execvp
, exit
, longjmp
, throw
(in C++), or similar mechanisms. Non-returning functions are
declared with a void
return type.
It helps the compiler’s ability to emit sensible warnings, following data-flow analysis, to declare which functions are non-returning. It can also help generate more-efficient code, as there is no need to save a return address when calling a non-returning function.
Gnulib has multiple ways to support such a declaration:
_Noreturn
keyword. No modules are needed, as Gnulib
arranges for <config.h>
to define _Noreturn
to an
appropriate replacement on platforms lacking it.
Unfortunately, although this approach works for all current C versions,
the _Noreturn
keyword is obsolescent in C23.
_GL_NORETURN_FUNC
for use in function declarations and function
definitions.
_GL_NORETURN_FUNCPTR
for use on function pointers.
The include file is <noreturn.h>
.
Which of the approaches to use? If the non-returning functions you
have to declare are unlikely to be accessed through function pointers,
you should use _Noreturn
; otherwise the module
noreturn
provides for better data-flow analysis and thus for
better warnings.
There is also an obsolete stdnoreturn
module, but its use is no
longer recommended.
The intprops
module consists of an include file <intprops.h>
that defines several macros useful for testing properties of integer
types.
Integer overflow is a common source of problems in programs written in C and other languages. In some cases, such as signed integer arithmetic in C programs, the resulting behavior is undefined, and practical platforms do not always behave as if integers wrap around reliably. In other cases, such as unsigned integer arithmetic in C, the resulting behavior is well-defined, but programs may still misbehave badly after overflow occurs.
Many techniques have been proposed to attack these problems. These include precondition testing, wraparound behavior where signed integer arithmetic is guaranteed to be modular, saturation semantics where overflow reliably yields an extreme value, undefined behavior sanitizers where overflow is guaranteed to trap, and various static analysis techniques.
Gnulib supports wraparound arithmetic and precondition testing, as these are relatively easy to support portably and efficiently. There are two families of precondition tests: the first, for integer types, is easier to use, while the second, for integer ranges, has a simple and straightforward portable implementation.
Like other Gnulib modules, the implementation of the intprops
module assumes that integers use a two’s complement representation,
but it does not assume that signed integer arithmetic wraps around.
See Other portability assumptions made by Gnulib.
TYPE_IS_INTEGER (t)
is an arithmetic constant
expression that yields 1 if the arithmetic type t is an integer type,
0 otherwise.
bool
counts as an integer type.
TYPE_SIGNED (t)
is an arithmetic constant expression
that yields 1 if the real type t is a signed integer type or a
floating type, 0 otherwise.
If t is an integer type, TYPE_SIGNED (t)
is an integer constant expression.
EXPR_SIGNED (e)
yields 1 if the real expression e
has a signed integer type or a floating type, 0 otherwise. If e is an
integer constant expression or an arithmetic constant expression,
EXPR_SIGNED (e)
is likewise. The expression
e is not evaluated, and EXPR_SIGNED
(e)
is typically optimized to a constant.
Example usage:
#include <intprops.h> #include <sys/types.h> enum { clock_t_is_integer = TYPE_IS_INTEGER (clock_t), uid_t_is_signed = TYPE_SIGNED (uid_t) }; int CLOCKS_PER_SEC_is_signed (void) { return EXPR_SIGNED (CLOCKS_PER_SEC); }
INT_BUFSIZE_BOUND (t)
is an integer constant
expression that is a bound on the size of the string representing an
integer type or expression t in decimal notation, including the
terminating null character and any leading -
character. For
example, if INT_BUFSIZE_BOUND (int)
is 12, any value of type
int
can be represented in 12 bytes or less, including the
terminating null. The bound is not necessarily tight.
Example usage:
#include <intprops.h> #include <stdio.h> int int_strlen (int i) { char buf[INT_BUFSIZE_BOUND (int)]; return sprintf (buf, "%d", i); }
INT_STRLEN_BOUND (t)
is an integer constant
expression that is a bound on the length of the string representing an
integer type or expression t in decimal notation, including any
leading -
character. This is one less than
INT_BUFSIZE_BOUND (t)
.
TYPE_MINIMUM (t)
and TYPE_MAXIMUM (t)
are
integer constant expressions equal to the minimum and maximum
values of the integer type t. These expressions are of the type
t.
Example usage:
#include <sys/types.h> #include <intprops.h> bool in_off_t_range (long long int a) { return TYPE_MINIMUM (off_t) <= a && a <= TYPE_MAXIMUM (off_t); }
Signed integer arithmetic has undefined behavior on overflow in C. Although almost all modern computers use two’s complement signed arithmetic that is well-defined to wrap around, C compilers routinely optimize assuming that signed integer overflow cannot occur, which means that a C program cannot easily get at the underlying machine arithmetic. For example:
if ((a + b < b) == (a < 0)) a += b; else printf ("overflow\n");
might not work as expected if a
and b
are signed,
because a compiler can assume that signed overflow cannot occur and
treat the entire if
expression as if it were true. And even if
a
is unsigned, the expression might not work as expected if
b
is negative or is wider than a
.
The following macros work around this problem by yielding an overflow
indication while computing the sum, difference, or product of two
integers. For example, if i
is of type int
,
INT_ADD_OK (INT_MAX - 1, 1, &i)
sets i
to
INT_MAX
and yields 1, whereas INT_ADD_OK (INT_MAX, 1,
&i)
yields 0.
Example usage:
#include <intprops.h> #include <stdio.h> /* Compute A * B, reporting whether overflow occurred. */ void print_product (long int a, long int b) { long int r; if (INT_MULTIPLY_OK (a, b, &r)) printf ("result is %ld\n", r); else printf ("overflow\n"); }
These macros work for both signed and unsigned integers, so they can
be used with integer types like time_t
that may or may not be
signed, depending on the platform.
These macros have the following restrictions:
INT_ADD_OK (a, b, r)
¶Compute the sum of a and b. If it fits into
*r
, store it there and yield 1. Otherwise yield
0, possibly modifying *r
to an unspecified value.
See above for restrictions.
INT_SUBTRACT_OK (a, b, r)
¶Compute the difference between a and b. If it fits into
*r
, store it there and yield 1. Otherwise yield
0, possibly modifying *r
to an unspecified value.
See above for restrictions.
INT_MULTIPLY_OK (a, b, r)
¶Compute the product of a and b. If it fits into
*r
, store it there and yield 1. Otherwise yield
0, possibly modifying *r
to an unspecified value.
See above for restrictions.
Other macros are available if you need wrapped-around results when overflow occurs (see Wraparound Arithmetic with Integers), or if you need to check for overflow in operations other than addition, subtraction, and multiplication (see Integer Type Overflow).
Signed integer arithmetic has undefined behavior on overflow in C.
Although almost all modern computers use two’s complement signed
arithmetic that is well-defined to wrap around, C compilers routinely
optimize assuming that signed integer overflow cannot occur, which
means that a C program cannot easily get at the underlying machine
arithmetic. For example, on a typical machine with 32-bit two’s
complement int
the expression INT_MAX + 1
does not
necessarily yield INT_MIN
, because the compiler may do
calculations with a 64-bit register, or may generate code that
traps on signed integer overflow.
The following macros work around this problem by storing the
wraparound value, i.e., the low-order bits of the correct answer, and
by yielding an overflow indication. For example, if i
is of
type int
, INT_ADD_WRAPV (INT_MAX, 1, &i)
sets i
to INT_MIN
and yields 1 on a two’s complement machine.
See Integer Type Overflow.
Example usage:
#include <intprops.h> #include <stdio.h> /* Print the low order bits of A * B, reporting whether overflow occurred. */ void print_product (long int a, long int b) { long int r; int overflow = INT_MULTIPLY_WRAPV (a, b, &r); printf ("result is %ld (%s)\n", r, (overflow ? "after overflow" : "no overflow")); }
These macros work for both signed and unsigned integers, so they can
be used with integer types like time_t
that may or may not be
signed, depending on the platform.
These macros have the following restrictions:
INT_ADD_WRAPV (a, b, r)
¶Store the low-order bits of the sum of a and b into
*r
. Yield 1 if overflow occurred, 0 if the
low-order bits are the mathematically-correct sum. See above for
restrictions.
INT_SUBTRACT_WRAPV (a, b, r)
¶Store the low-order bits of the difference between a and b
into *r
. Yield 1 if overflow occurred, 0 if the
low-order bits are the mathematically-correct difference. See above
for restrictions.
INT_MULTIPLY_WRAPV (a, b, r)
¶Store the low-order bits of the product of a and b into
*r
. Yield 1 if overflow occurred, 0 if the
low-order bits are the mathematically-correct product. See above for
restrictions.
If your code includes <intprops.h>
only for these _WRAPV
macros, you may prefer to use Gnulib’s stdckdint
module
instead, as it supports similar macros that were standardized in C23
and are therefore independent of Gnulib if your code can assume C23 or
later. See stdckdint.h.
Other macros are available if you do not need wrapped-around results when overflow occurs (see Checking Integer Overflow), or if you need to check for overflow in operations other than addition, subtraction, and multiplication (see Integer Type Overflow).
Although unsigned integer arithmetic wraps around modulo a power of
two, signed integer arithmetic has undefined behavior on overflow in
C. Almost all modern computers use two’s complement signed
arithmetic that is well-defined to wrap around, but C compilers
routinely optimize based on the assumption that signed integer
overflow cannot occur, which means that a C program cannot easily get
at the underlying machine behavior. For example, the signed integer
expression (a + b < b) != (a < 0)
is not a reliable test for
whether a + b
overflows, because a compiler can assume that
signed overflow cannot occur and treat the entire expression as if it
were false.
These macros yield 1 if the corresponding C operators overflow, 0 otherwise. They work correctly on all known practical hosts, and do not rely on undefined behavior due to signed arithmetic overflow. They are integer constant expressions if their arguments are. They are typically easier to use than the integer range overflow macros (see Integer Range Overflow), and they support more operations and evaluation contexts than the integer overflow checking macros (see Checking Integer Overflow) or the wraparound macros (see Wraparound Arithmetic with Integers).
These macros can be tricky to use with arguments narrower than
int
. For example, in the common case with 16-bit short
int
and 32-bit int
, if a
and b
are of type
short int
then INT_MULTIPLY_OVERFLOW (a, b)
always
yields 0, as a * b
cannot overflow due to C’s rule that
a
and b
are widened to int
before multiplying.
For this reason, often it is better to use the integer overflow
checking macros (see Checking Integer Overflow) or the wraparound
macros (see Wraparound Arithmetic with Integers) when checking for overflow in
addition, subtraction, or multiplication.
Example usage:
#include <intprops.h> #include <limits.h> #include <stdio.h> /* Print A * B if in range, an overflow indicator otherwise. */ void print_product (long int a, long int b) { if (INT_MULTIPLY_OVERFLOW (a, b)) printf ("multiply would overflow"); else printf ("product is %ld", a * b); } /* Does the product of two ints always fit in a long int? */ enum { INT_PRODUCTS_FIT_IN_LONG = ! (INT_MULTIPLY_OVERFLOW ((long int) INT_MIN, INT_MIN)) };
These macros have the following restrictions:
These macros are tuned for their last argument being a constant.
INT_ADD_OVERFLOW (a, b)
¶Yield 1 if a + b
would overflow, 0 otherwise. See above for
restrictions.
INT_SUBTRACT_OVERFLOW (a, b)
¶Yield 1 if a - b
would overflow, 0 otherwise. See above for
restrictions.
INT_NEGATE_OVERFLOW (a)
¶Yields 1 if -a
would overflow, 0 otherwise.
See above for restrictions.
INT_MULTIPLY_OVERFLOW (a, b)
¶Yield 1 if a * b
would overflow, 0 otherwise. See above for
restrictions.
INT_DIVIDE_OVERFLOW (a, b)
¶Yield 1 if a / b
would overflow, 0 otherwise. See above for
restrictions. Division overflow can happen on two’s complement hosts
when dividing the most negative integer by −1. This macro does
not check for division by zero.
INT_REMAINDER_OVERFLOW (a, b)
¶Yield 1 if a % b
would overflow, 0 otherwise. See above for
restrictions. Remainder overflow can happen on two’s complement hosts
when dividing the most negative integer by −1; although the
mathematical result is always 0, in practice some implementations
trap, so this counts as an overflow. This macro does not check for
division by zero.
INT_LEFT_SHIFT_OVERFLOW (a, b)
¶Yield 1 if a << b
would overflow, 0 otherwise. See above for
restrictions. The C standard says that behavior is undefined for
shifts unless 0≤b<w where w is a’s word
width, and that when a is negative then a <<
b
has undefined behavior, but this macro does not check these
other restrictions.
These macros yield 1 if the corresponding C operators might not yield numerically correct answers due to arithmetic overflow, and 0 if if the operators do not overflow. They do not rely on undefined or implementation-defined behavior. They are integer constant expressions if their arguments are. Their implementations are simple and straightforward, but they are typically harder to use than the integer type overflow macros. See Integer Type Overflow.
Although the implementation of these macros is similar to that suggested in the SEI CERT C Secure Coding Standard, in its two sections “INT30-C. Ensure that unsigned integer operations do not wrap” and “INT32-C. Ensure that operations on signed integers do not result in overflow”, Gnulib’s implementation was derived independently of CERT’s suggestions.
Example usage:
#include <intprops.h> #include <limits.h> #include <stdio.h> void print_product (long int a, long int b) { if (INT_MULTIPLY_RANGE_OVERFLOW (a, b, LONG_MIN, LONG_MAX)) printf ("multiply would overflow"); else printf ("product is %ld", a * b); } /* Does the product of two ints always fit in a long int? */ enum { INT_PRODUCTS_FIT_IN_LONG = ! (INT_MULTIPLY_RANGE_OVERFLOW ((long int) INT_MIN, (long int) INT_MIN, LONG_MIN, LONG_MAX)) };
These macros have the following restrictions:
(unsigned int) 0
.
These macros are tuned for constant min and max. For
commutative operations such as a + b
, they are also
tuned for constant b.
INT_ADD_RANGE_OVERFLOW (a, b, min, max)
¶Yield 1 if a + b
would overflow in
[min,max] integer arithmetic, 0 otherwise.
See above for restrictions.
INT_SUBTRACT_RANGE_OVERFLOW (a, b, min, max)
¶Yield 1 if a - b
would overflow in
[min,max] integer arithmetic, 0 otherwise.
See above for restrictions.
INT_NEGATE_RANGE_OVERFLOW (a, min, max)
¶Yield 1 if -a
would overflow in [min,max]
integer arithmetic, 0 otherwise. See above for restrictions.
INT_MULTIPLY_RANGE_OVERFLOW (a, b, min, max)
¶Yield 1 if a * b
would overflow in
[min,max] integer arithmetic, 0 otherwise.
See above for restrictions.
INT_DIVIDE_RANGE_OVERFLOW (a, b, min, max)
¶Yield 1 if a / b
would overflow in
[min,max] integer arithmetic, 0 otherwise.
See above for restrictions.
Division overflow can happen on two’s complement hosts when dividing
the most negative integer by −1. This macro does not check for
division by zero.
INT_REMAINDER_RANGE_OVERFLOW (a, b, min, max)
¶Yield 1 if a % b
would overflow in
[min,max] integer arithmetic, 0 otherwise.
See above for restrictions.
Remainder overflow can happen on two’s complement hosts when dividing
the most negative integer by −1; although the mathematical
result is always 0, in practice some implementations trap, so this
counts as an overflow. This macro does not check for division by
zero.
INT_LEFT_SHIFT_RANGE_OVERFLOW (a, b, min, max)
¶Yield 1 if a << b
would overflow in
[min,max] integer arithmetic, 0 otherwise.
See above for restrictions.
Here, min and max are for a only, and b need
not be of the same type as the other arguments. The C standard says
that behavior is undefined for shifts unless 0≤b<w
where w is a’s word width, and that when a is negative
then a << b
has undefined behavior, but this macro
does not check these other restrictions.
In order to mark functions as static inline
, the only
prerequisite you need is an AC_REQUIRE([AC_C_INLINE])
.
No Gnulib module is needed.
The extern-inline
module supports the use of C99-style
extern inline
functions so that the code still runs on
compilers that do not support this feature correctly.
C code ordinarily should not use inline
. Typically it is
better to let the compiler figure out whether to inline, as compilers
are pretty good about optimization nowadays. In this sense,
inline
is like register
, another keyword that is
typically no longer needed.
Functions defined (not merely declared) in headers are an exception,
as avoiding inline
would commonly cause problems for these
functions. Suppose aaa.h defines the function aaa_fun
,
and aaa.c, bbb.c and ccc.c all include
aaa.h. If code is intended to portable to non-C99 compilers,
aaa_fun
cannot be declared with the C99 inline
keyword.
This problem cannot be worked around by making aaa_fun
an
ordinary function, as it would be defined three times with external
linkage and the definitions would clash. Although aaa_fun
could be a static function, with separate compilation if
aaa_fun
is not inlined its code will appear in the executable
three times.
To avoid this code bloat, aaa.h can do this:
/* aaa.h */ /* #include any other headers here */ #ifndef _GL_INLINE_HEADER_BEGIN #error "Please include config.h first." #endif _GL_INLINE_HEADER_BEGIN #ifndef AAA_INLINE # define AAA_INLINE _GL_INLINE #endif ... AAA_INLINE int aaa_fun (int i) { return i + 1; } ... _GL_INLINE_HEADER_END
and aaa.c can do this:
/* aaa.c */ #include <config.h> #define AAA_INLINE _GL_EXTERN_INLINE #include <aaa.h>
whereas bbb.c and ccc.c can include aaa.h in the
usual way. C99 compilers expand AAA_INLINE
to C99-style
inline
usage, where aaa_fun
is declared extern
inline
in aaa.c and plain inline
in other modules.
Non-C99 compilers that are compatible with GCC use GCC-specific syntax
to accomplish the same ends. Other non-C99 compilers use static
inline
so they suffer from code bloat, but they are not mainline
platforms and will die out eventually.
_GL_INLINE
is a portable alternative to C99 plain inline
.
_GL_EXTERN_INLINE
is a portable alternative to C99 extern inline
.
Invoke _GL_INLINE_HEADER_BEGIN
before all uses of
_GL_INLINE
in an include file. This suppresses some
bogus warnings in GCC versions before 5.1. If an include file includes
other files, it is better to invoke this macro after including the
other files.
Invoke _GL_INLINE_HEADER_END
after all uses of
_GL_INLINE
in an include file.
Usually, when a program gets invoked, its file descriptors 0 (for standard input), 1 (for standard output), and 2 (for standard error) are open. But there are situations when some of these file descriptors are closed. These situations can arise when
close()
on the file descriptor before
exec
, or
posix_spawn_file_actions_addclose()
for
the file descriptor before posix_spawn
or posix_spawnp
, or
<&-
for closing standard input,
>&-
for closing standard output, or
2>&-
for closing standard error.
When a closed file descriptor is accessed through a system call, such as
fcntl()
, fstat()
, read()
, or write()
, the
system calls fails with error EBADF
("Bad file descriptor").
When a new file descriptor is allocated, the operating system chooses the smallest non-negative integer that does not yet correspond to an open file descriptor. So, when a given fd (0, 1, or 2) is closed, opening a new file descriptor may assign the new file descriptor to this fd. This can have unintended effects, because now standard input/output/error of your process is referring to a file that was not meant to be used in that role.
This situation is a security risk because the behaviour of the program in this situation was surely never tested, therefore anything can happen then – from overwriting precious files of the user to endless loops.
To deal with this situation, you first need to determine whether your program is affected by the problem.
open()
, openat()
, creat()
dup()
fopen()
, freopen()
pipe()
, pipe2()
, popen()
opendir()
tmpfile()
, mkstemp()
, mkstemps()
, mkostemp()
,
mkostemps()
Note that you also have to consider the libraries that your program uses.
O_RDONLY
mode will produce an error EBADF
, as desired.
If your program is affected, what is the mitigation?
Some operating systems install open file descriptors in place of the
closed ones, either in the exec
system call or during program
startup. When such a file descriptor is accessed through a system call,
it behaves like an open file descriptor opened for the “wrong” direction:
the system calls fcntl()
and fstat()
succeed, whereas
read()
from fd 0 and write()
to fd 1 or 2 fail with error
EBADF
("Bad file descriptor"). The important point here is that
when your program allocates a new file descriptor, it will have a value
greater than 2.
This mitigation is enabled on HP-UX, for all programs, and on glibc, FreeBSD, NetBSD, OpenBSD, but only for setuid or setgid programs. Since it is operating system dependent, it is not a complete mitigation.
For a complete mitigation, Gnulib provides two alternative sets of modules:
xstdopen
module.
*-safer
modules:
fcntl-safer
,
openat-safer
,
unistd-safer
,
fopen-safer
,
freopen-safer
,
pipe2-safer
,
popen-safer
,
dirent-safer
,
tmpfile-safer
,
stdlib-safer
.
The approach with the xstdopen
module is simpler, but it adds three
system calls to program startup. Whereas the approach with the *-safer
modules is more complex, but adds no overhead (no additional system calls)
in the normal case.
To use the approach with the xstdopen
module:
xstdopen
from Gnulib.
main
function, include
"xstdopen.h"
.
main
function, near the beginning, namely right after
the i18n related initializations (setlocale
, bindtextdomain
,
textdomain
invocations, if any) and
the closeout
initialization (if any), insert the invocation:
/* Ensure that stdin, stdout, stderr are open. */ xstdopen ();
To use the approach with the *-safer
modules:
Do so according to this table:
Function | Module | Header file |
---|---|---|
open() | fcntl-safer | "fcntl--.h" |
openat() | openat-safer | "fcntl--.h" |
creat() | fcntl-safer | "fcntl--.h" |
dup() | unistd-safer | "unistd--.h" |
fopen() | fopen-safer | "stdio--.h" |
freopen() | freopen-safer | "stdio--.h" |
pipe() | unistd-safer | "unistd--.h" |
pipe2() | pipe2-safer | "unistd--.h" |
popen() | popen-safer | "stdio--.h" |
opendir() | dirent-safer | "dirent--.h" |
tmpfile() | tmpfile-safer | "stdio--.h" |
mkstemp() | stdlib-safer | "stdlib--.h" |
mkstemps() | stdlib-safer | "stdlib--.h" |
mkostemp() | stdlib-safer | "stdlib--.h" |
mkostemps() | stdlib-safer | "stdlib--.h" |
Strings in C are usually represented by a character sequence with a terminating NUL character. A ‘char *’, pointer to the first byte of this character sequence, is what gets passed around as function argument or return value.
The major restriction of this string representation is that it cannot
handle strings that contain NUL characters: such strings will appear
shorter than they were meant to be. In most application areas, this is
not a problem, and the char *
type is well usable.
In areas where strings with embedded NUL characters need to be handled,
the common approach is to use a char *ptr
pointer variable
together with a size_t nbytes
variable (or an idx_t nbytes
variable, if you want to avoid problems due to integer overflow). This
works fine in code that constructs or manipulates strings with embedded
NUL characters. But when it comes to storing them, for example
in an array or as key or value of a hash table, one needs a type that
combines these two fields.
The Gnulib modules string-desc
, xstring-desc
, and
string-desc-quotearg
provide such a type. We call it a
“string descriptor” and name it string_desc_t
.
The type string_desc_t
is a struct that contains a pointer to the
first byte and the number of bytes of the memory region that make up the
string. An additional terminating NUL byte, that may be present in
memory, is not included in this byte count. This type implements the
same concept as std::string_view
in C++, or the String
type in Java.
A string_desc_t
can be passed to a function as an argument, or
can be the return value of a function. This is type-safe: If, by
mistake, a programmer passes a string_desc_t
to a function that
expects a char *
argument, or vice versa, or assigns a
string_desc_t
value to a variable of type char *
, or
vice versa, the compiler will report an error.
Functions related to string descriptors are provided:
"string-desc.h"
,
"string-desc.h"
,
"xstring-desc.h"
,
"string-desc.h"
.
For outputting a string descriptor, the *printf
family of
functions cannot be used directly. A format string directive such as
"%.*s"
would not work:
int
, and thus
would not work for strings longer than INT_MAX
bytes.
Therefore Gnulib offers
string_desc_fwrite
that outputs a string descriptor to
a FILE
stream,
string_desc_write
that outputs a string descriptor to
a file descriptor,
quotearg
based functions, that
allow to specify the escaping rules in detail.
The functionality is thus split across three modules as follows:
string-desc
, under LGPL, defines the type and
elementary functions.
xstring-desc
, under GPL, defines the memory-allocating
functions with out-of-memory checking.
string-desc-quotearg
, under GPL, defines the
quotearg
based functions.
Gnulib provides several generic container data types. They can be used to organize collections of application-defined objects.
Data type | Details | Module | Main include file | Include file for operations with out-of-memory checking |
---|---|---|---|---|
Sequential list | Can contain any number of objects in any given order. Duplicates are allowed, but can optionally be forbidden. | list | "gl_list.h" | "gl_xlist.h" |
Set | Can contain any number of objects; the order does not matter. Duplicates (in the sense of the comparator) are forbidden. | set | "gl_set.h" | "gl_xset.h" |
Ordered set | Can contain any number of objects in the order of a given comparator function. Duplicates (in the sense of the comparator) are forbidden. | oset | "gl_oset.h" | "gl_xoset.h" |
Map | Can contain any number of (key, value) pairs, where keys and values are objects; there are no (key, value1) and (key, value2) pairs with the same key (in the sense of a given comparator function). | map | "gl_map.h" | "gl_xmap.h" |
Ordered map | Can contain any number of (key, value) pairs, where keys and values are objects; the (key, value) pairs are ordered by the key, in the order of a given comparator function; there are no (key, value1) and (key, value2) pairs with the same key (in the sense of the comparator function). | omap | "gl_omap.h" | "gl_xomap.h" |
Operations without out-of-memory checking (suitable for use in libraries) are declared in the “main include file”. Whereas operations with out-of-memory checking (suitable only in programs) are declared in the “include file for operations with out-of-memory checking”.
For each of the data types, several implementations are available, with
different performance profiles with respect to the available operations.
This enables you to start with the simplest implementation (ARRAY) initially,
and switch to a more suitable implementation after profiling your application.
The implementation of each container instance is specified in a single place
only: in the invocation of the function gl_*_create_empty
that creates
the instance.
The implementations and the guaranteed average performance for the operations for the “sequential list” data type are:
Operation | ARRAY | CARRAY | LINKED | TREE | LINKEDHASH with duplicates | LINKEDHASH without duplicates | TREEHASH with duplicates | TREEHASH without duplicates |
---|---|---|---|---|---|---|---|---|
gl_list_size | O(1) | O(1) | O(1) | O(1) | O(1) | O(1) | O(1) | O(1) |
gl_list_node_value | O(1) | O(1) | O(1) | O(1) | O(1) | O(1) | O(1) | O(1) |
gl_list_node_set_value | O(1) | O(1) | O(1) | O(1) | O(1) | O(1) | O((log n)2) | O(1) |
gl_list_next_node | O(1) | O(1) | O(1) | O(log n) | O(1) | O(1) | O(log n) | O(log n) |
gl_list_previous_node | O(1) | O(1) | O(1) | O(log n) | O(1) | O(1) | O(log n) | O(log n) |
gl_list_first_node | O(1) | O(1) | O(1) | O(log n) | O(1) | O(1) | O(log n) | O(log n) |
gl_list_last_node | O(1) | O(1) | O(1) | O(log n) | O(1) | O(1) | O(log n) | O(log n) |
gl_list_get_at | O(1) | O(1) | O(n) | O(log n) | O(n) | O(n) | O(log n) | O(log n) |
gl_list_get_first | O(1) | O(1) | O(1) | O(log n) | O(1) | O(1) | O(log n) | O(log n) |
gl_list_get_last | O(1) | O(1) | O(1) | O(log n) | O(1) | O(1) | O(log n) | O(log n) |
gl_list_set_at | O(1) | O(1) | O(n) | O(log n) | O(n) | O(n) | O((log n)2) | O(log n) |
gl_list_set_first | O(1) | O(1) | O(1) | O(log n) | O(n) | O(1) | O((log n)2) | O(log n) |
gl_list_set_last | O(1) | O(1) | O(1) | O(log n) | O(n) | O(1) | O((log n)2) | O(log n) |
gl_list_search | O(n) | O(n) | O(n) | O(n) | O(n) | O(1) | O(log n) | O(1) |
gl_list_search_from | O(n) | O(n) | O(n) | O(n) | O(n) | O(1) | O((log n)2) | O(log n) |
gl_list_search_from_to | O(n) | O(n) | O(n) | O(n) | O(n) | O(1) | O((log n)2) | O(log n) |
gl_list_indexof | O(n) | O(n) | O(n) | O(n) | O(n) | O(n) | O(log n) | O(log n) |
gl_list_indexof_from | O(n) | O(n) | O(n) | O(n) | O(n) | O(n) | O((log n)2) | O(log n) |
gl_list_indexof_from_to | O(n) | O(n) | O(n) | O(n) | O(n) | O(n) | O((log n)2) | O(log n) |
gl_list_add_first | O(n) | O(1) | O(1) | O(log n) | O(1) | O(1) | O((log n)2) | O(log n) |
gl_list_add_last | O(1) | O(1) | O(1) | O(log n) | O(1) | O(1) | O((log n)2) | O(log n) |
gl_list_add_before | O(n) | O(n) | O(1) | O(log n) | O(1) | O(1) | O((log n)2) | O(log n) |
gl_list_add_after | O(n) | O(n) | O(1) | O(log n) | O(1) | O(1) | O((log n)2) | O(log n) |
gl_list_add_at | O(n) | O(n) | O(n) | O(log n) | O(n) | O(n) | O((log n)2) | O(log n) |
gl_list_remove_node | O(n) | O(n) | O(1) | O(log n) | O(n) | O(1) | O((log n)2) | O(log n) |
gl_list_remove_at | O(n) | O(n) | O(n) | O(log n) | O(n) | O(n) | O((log n)2) | O(log n) |
gl_list_remove_first | O(n) | O(1) | O(1) | O(log n) | O(n) | O(1) | O((log n)2) | O(log n) |
gl_list_remove_last | O(1) | O(1) | O(1) | O(log n) | O(n) | O(1) | O((log n)2) | O(log n) |
gl_list_remove | O(n) | O(n) | O(n) | O(n) | O(n) | O(1) | O((log n)2) | O(log n) |
gl_list_iterator | O(1) | O(1) | O(1) | O(log n) | O(1) | O(1) | O(log n) | O(log n) |
gl_list_iterator_from_to | O(1) | O(1) | O(n) | O(log n) | O(n) | O(n) | O(log n) | O(log n) |
gl_list_iterator_next | O(1) | O(1) | O(1) | O(log n) | O(1) | O(1) | O(log n) | O(log n) |
gl_sortedlist_search | O(log n) | O(log n) | O(n) | O(log n) | O(n) | O(n) | O(log n) | O(log n) |
gl_sortedlist_search_from | O(log n) | O(log n) | O(n) | O(log n) | O(n) | O(n) | O(log n) | O(log n) |
gl_sortedlist_indexof | O(log n) | O(log n) | O(n) | O(log n) | O(n) | O(n) | O(log n) | O(log n) |
gl_sortedlist_indexof_from | O(log n) | O(log n) | O(n) | O(log n) | O(n) | O(n) | O(log n) | O(log n) |
gl_sortedlist_add | O(n) | O(n) | O(n) | O(log n) | O(n) | O(n) | O((log n)2) | O(log n) |
gl_sortedlist_remove | O(n) | O(n) | O(n) | O(log n) | O(n) | O(n) | O((log n)2) | O(log n) |
The implementations and the guaranteed average performance for the operations for the “set” data type are:
Operation | ARRAY | LINKEDHASH, HASH |
---|---|---|
gl_set_size | O(1) | O(1) |
gl_set_add | O(n) | O(1) |
gl_set_remove | O(n) | O(1) |
gl_set_search | O(n) | O(1) |
gl_set_iterator | O(1) | O(1) |
gl_set_iterator_next | O(1) | O(1) |
The implementations and the guaranteed average performance for the operations for the “ordered set” data type are:
Operation | ARRAY | TREE |
---|---|---|
gl_oset_size | O(1) | O(1) |
gl_oset_add | O(n) | O(log n) |
gl_oset_remove | O(n) | O(log n) |
gl_oset_search | O(log n) | O(log n) |
gl_oset_search_atleast | O(log n) | O(log n) |
gl_oset_iterator | O(1) | O(log n) |
gl_oset_iterator_next | O(1) | O(log n) |
The implementations and the guaranteed average performance for the operations for the “map” data type are:
Operation | ARRAY | LINKEDHASH, HASH |
---|---|---|
gl_map_size | O(1) | O(1) |
gl_map_get | O(n) | O(1) |
gl_map_put | O(n) | O(1) |
gl_map_remove | O(n) | O(1) |
gl_map_search | O(n) | O(1) |
gl_map_iterator | O(1) | O(1) |
gl_map_iterator_next | O(1) | O(1) |
The implementations and the guaranteed average performance for the operations for the “ordered map” data type are:
Operation | ARRAY | TREE |
---|---|---|
gl_omap_size | O(1) | O(1) |
gl_omap_get | O(log n) | O(log n) |
gl_omap_put | O(n) | O(log n) |
gl_omap_remove | O(n) | O(log n) |
gl_omap_search | O(log n) | O(log n) |
gl_omap_search_atleast | O(log n) | O(log n) |
gl_omap_iterator | O(1) | O(log n) |
gl_omap_iterator_next | O(1) | O(log n) |
For C++, Gnulib provides a C++ template class for each of these container data types.
Data type | C++ class | Module | Include file |
---|---|---|---|
Sequential list | gl_List | list-c++ | "gl_list.hh" |
Set | gl_Set | set-c++ | "gl_set.hh" |
Ordered set | gl_OSet | oset-c++ | "gl_oset.hh" |
Map | gl_Map | map-c++ | "gl_map.hh" |
Ordered map | gl_OMap | omap-c++ | "gl_omap.hh" |
The hamt
module implements the hash array mapped trie (HAMT) data
structure. This is a data structure that contains (key, value) pairs.
Lookup of a (key, value) pair given the key is on average an O(1)
operation, assuming a good hash function for the keys is employed.
The HAMT data structure is useful when you want modifications (additions of pairs, removal, value changes) to be visible only to some part of your program, whereas other parts of the program continue to use the unmodified HAMT. The HAMT makes this possible in a space-efficient manner: the modified and the unmodified HAMT share most of their allocated memory. It is also time-efficient: Every such modification is O(1) on average, again assuming a good hash function for the keys.
A HAMT can be used whenever an ordinary hash table would be used. It does however, provide non-destructive updating operations without the need to copy the whole container. On the other hand, a hash table is simpler so that its performance may be better when non-destructive update operations are not needed.
For example, a HAMT can be used to model the dynamic environment in a LISP interpreter. Updating a value in the dynamic environment of one continuation frame would not modify values in earlier frames.
To use the module, include hamt.h
in your code. The public
interface is documented in that header file. You have to provide a hash
function and an equivalence relation, which defines key equality. The
module includes a test file test-hamt.c
, which demonstrates how
the API can be used.
In the current implementation, each inner node of the HAMT can store up to 32 = 2^5 entries and subtries. Whenever a collision between the initial bits of the hash values of two entries would happen, the next 5 bits of the hash values are examined and the two entries pushed down one level in the trie.
HAMTs have the same average access times as hash tables but grow and shrink dynamically, so they use memory more economically and do not have to be periodically resized.
They were described and analyzed in Phil Bagwell (2000). Ideal Hash Trees (Report). Infoscience Department, École Polytechnique Fédérale de Lausanne.
The persistence aspect of the HAMT data structure, which means that each updating operation (like inserting, replacing, or removing an entry) returns a new HAMT while leaving the original one intact, is achieved through structure sharing, which is even safe in the presence of multiple threads when the used C compiler supports atomics.
The module ‘argmatch’ provides a simple textual user interface to a finite choice. It is for example well suited to recognize arguments of options or values of environment variables that accept a fixed set of valid choices.
These choices may be denoted by synonyms, such as ‘none’ and ‘off’ below.
$ my_cp --backup=none foo bar $ my_cp --backup=non foo bar $ my_cp --backup=no foo bar $ my_cp --backup=n foo bar my_cp: ambiguous argument 'n' for 'backup type' Valid arguments are: - 'no', 'none', 'off' - 'numbered', 't', 'newstyle' - 'existing', 'nil', 'numbered-existing' - 'simple', 'never', 'single' Try 'my_cp --help' for more information. $ my_cp --backup=num foo bar $ my_cp --backup=true foo bar my_cp: invalid argument 'true' for 'backup type' Valid arguments are: - 'no', 'none', 'off' - 'numbered', 't', 'newstyle' - 'existing', 'nil', 'numbered-existing' - 'simple', 'never', 'single' Try 'my_cp --help' for more information.
To set up argmatch
, first call ‘ARGMATCH_DEFINE_GROUP
(name, type)’ with the name of the argmatch group name, and the
value type. For instance:
enum backup_type { no_backups, simple_backups, numbered_existing_backups, numbered_backups }; ARGMATCH_DEFINE_GROUP (backup, enum backup_type);
This defines a few types and functions named argmatch_name_*
.
Introduce the array that defines the mapping from user-input to actual
value, with a terminator:
static const argmatch_backup_arg argmatch_backup_args[] = { { "no", no_backups }, { "none", no_backups }, { "off", no_backups }, { "simple", simple_backups }, { "never", simple_backups }, { "single", simple_backups }, { "existing", numbered_existing_backups }, { "nil", numbered_existing_backups }, { "numbered-existing", numbered_existing_backups }, { "numbered", numbered_backups }, { "t", numbered_backups }, { "newstyle", numbered_backups }, { NULL, no_backups } };
Then introduce the array that defines the values, also with a terminator. Document only once per group of synonyms:
static const argmatch_backup_doc argmatch_backup_docs[] = { { "no", N_("never make backups (even if --backup is given)") }, { "numbered", N_("make numbered backups") }, { "existing", N_("numbered if numbered backups exist, simple otherwise") }, { "simple", N_("always make simple backups") }, { NULL, NULL } };
Finally, define the argmatch group:
const argmatch_backup_group_type argmatch_backup_group = { argmatch_backup_args, argmatch_backup_docs, N_("\ The backup suffix is '~', unless set with --suffix or SIMPLE_BACKUP_SUFFIX.\n\ The version control method may be selected via the --backup option or through\n\ the VERSION_CONTROL environment variable. Here are the values:\n"), NULL };
To use the argmatch group:
ptrdiff_t i = argmatch_backup_choice ("--backup", "none"); // argmatch_backup_group.args[i].arg is "none", so its value // is argmatch_backup_group.args[i].val. // Return -1 on invalid argument, and -2 on ambiguity. enum backup_type val = *argmatch_backup_value ("--backup", "none"); // Returns a pointer to the value, and exit on errors. // So argmatch_backup_group.args[i].val == val. const char *arg = argmatch_backup_argument (&no_backups); // arg is "no". // Print the documentation on stdout. argmatch_backup_usage (stdout); // Gives: // // The backup suffix is '~', unless set with --suffix or SIMPLE_BACKUP_SUFFIX. // The version control method may be selected via the --backup option or through // the VERSION_CONTROL environment variable. Here are the values: // // no, none, off never make backups (even if --backup is given) // numbered, t, newstyle // make numbered backups // existing, nil, numbered-existing // numbered if numbered backups exist, simple otherwise // simple, never, single // always make simple backups
Gnulib provides ‘quote’ and ‘quotearg’ modules to help with quoting text, such as file names, in messages to the user. Here’s an example of using ‘quote’:
#include <quote.h> ... error (0, errno, _("cannot change owner of %s"), quote (fname));
This differs from
error (0, errno, _("cannot change owner of '%s'"), fname);
in that quote
escapes unusual characters in
fname
, e.g., ‘'’ and control characters like ‘\n’.
However, a caveat: quote
reuses the storage that it returns.
Hence if you need more than one thing quoted at the same time, you
need to use quote_n
.
Also, the quote
module is not suited for multithreaded applications.
In that case, you have to use quotearg_alloc
, defined in the
‘quotearg’ module, which is decidedly less convenient.
Gnulib has two modules for retrieving the name of the currently executing
program: progname
and getprogname
.
The progname
module defines a variable program_name
.
It contains the name of the currently executing program, on all platforms.
But it cannot be used implicitly: It requires that every main
function be modified to invoke set_program_name (argv[0])
as one
of its first actions.
The getprogname
module defines a function getprogname()
.
It returns the name of the currently executing program, on most platforms.
The advantage of this module is that it can be used without prior
initializations. But it has limitations: In some rare situations, it
cannot determine the name; then it returns "?"
instead. And on
some platforms, it returns a truncated program name.
The error
function uses the getprogname
module.
The gcd
function returns the greatest common divisor of two numbers
a > 0
and b > 0
. It is the caller’s responsibility to ensure
that the arguments are non-zero.
If you need a gcd function for an integer type larger than ‘unsigned long’, you can include the gcd.c implementation file with parametrization. The parameters are:
The created function has the prototype
WORD_T GCD (WORD_T a, WORD_T b);
If you need the least common multiple of two numbers, it can be computed
like this: lcm(a,b) = (a / gcd(a,b)) * b
or
lcm(a,b) = a * (b / gcd(a,b))
.
Avoid the formula lcm(a,b) = (a * b) / gcd(a,b)
because—although
mathematically correct—it can yield a wrong result, due to integer overflow.
In some applications it is useful to have a function taking the gcd of two signed numbers. In this case, the gcd function result is usually normalized to be non-negative (so that two gcd results can be compared in magnitude or compared against 1, etc.). Note that in this case the prototype of the function has to be
unsigned long gcd (long a, long b);
and not
long gcd (long a, long b);
because gcd(LONG_MIN,LONG_MIN) = -LONG_MIN = LONG_MAX + 1
does not
fit into a signed ‘long’.
The module ‘timevar’ provides a simple self-profiling facility, based on timers.
Execution times (seconds) read : 0.09 (19%) usr 0.08 (80%) sys 0.09 (18%) wall read: scan : 0.04 ( 9%) usr 0.08 (80%) sys 0.12 (26%) wall read: parse : 0.05 (10%) usr 0.00 ( 0%) sys 0.05 (10%) wall work : 0.33 (70%) usr 0.00 ( 0%) sys 0.35 (71%) wall work: phase 1 : 0.30 (64%) usr 0.00 ( 0%) sys 0.30 (64%) wall work: phase 2 : 0.13 (28%) usr 0.00 ( 0%) sys 0.14 (29%) wall output : 0.04 ( 9%) usr 0.02 (20%) sys 0.04 ( 8%) wall total time : 0.47 0.10 0.49
To set up timevar
, copy the stub file
gnulib/lib/timevar.def next to where timevar.h and
timevar.c were imported in your project, and define your timers
there. For instance:
/* The total execution time. Mandatory. */ DEFTIMEVAR (tv_total, "total time") /* Examples. */ DEFTIMEVAR (tv_read, "read") DEFTIMEVAR (tv_work, "work") DEFTIMEVAR (tv_work_1, "work: phase 1") DEFTIMEVAR (tv_work_2, "work: phase 2") DEFTIMEVAR (tv_output, "output")
Do not remove tv_total
, it is mandatory. You may change its
associated string.
Use timevar_push
/timevar_pop
to start/stop timers, as in
the following example.
#include <config.h> #include "timevar.h" #include <stdio.h> #include "read.h" #include "work.h" #include "output.h" int main (void) { timevar_enabled = true; timevar_init (); timevar_start (tv_total); timevar_push (tv_read); reader (); timevar_pop (tv_read); timevar_push (tv_work); work (); timevar_pop (tv_work); timevar_push (tv_output); output (); timevar_pop (tv_output); timevar_stop (tv_total); timevar_print (stderr); }
with, for instance, in work.c
#include <config.h> #include "work.h" void work (void) { timevar_push (tv_work_phase1); work1 (); timevar_pop (tv_work_phase1); timevar_push (tv_work_phase2); work2 (); timevar_pop (tv_work_phase2); }
The module ‘check-version’ can be useful when your gnulib
application is a system library. You will typically wrap the call to
the check_version
function through a library API, your library
header file may contain:
#define STRINGPREP_VERSION "0.5.18" ... extern const char *stringprep_check_version (const char *req_version);
To avoid ELF symbol collisions with other libraries that use the ‘check-version’ module, add to config.h through a AC_DEFINE something like:
AC_DEFINE(check_version, stringprep_check_version, [Rename check_version.])
The stringprep_check_version
function will thus be implemented
by the check_version
module.
There are two uses of the interface. The first is a way to provide for applications to find out the version number of the library it uses. The application may contain diagnostic code such as:
printf ("Stringprep version: header %s library %s", STRINGPREP_VERSION, stringprep_check_version (NULL));
Separating the library and header file version can be useful when searching for version mismatch related problems.
The second uses is as a rudimentary test of proper library version, by making sure the application get a library version that is the same, or newer, than the header file used when building the application. This doesn’t catch all problems, libraries may change backwards incompatibly in later versions, but enable applications to require a certain minimum version before it may proceed.
Typical uses look like:
/* Check version of libgcrypt. */ if (!gcry_check_version (GCRYPT_VERSION)) die ("version mismatch\n");
It has been a pain for many users of GNU packages for a long time that
packages are not relocatable. It means a user cannot copy a program,
installed by another user on the same machine, to his home directory,
and have it work correctly (including i18n). So many users need to go
through configure; make; make install
with all its
dependencies, options, and hurdles.
Red Hat, Debian, and other binary distributions solve the “ease of installation” problem, but they hardwire path names, usually to /usr or /usr/local. This means that users need root privileges to install a binary package, and prevents installing two different versions of the same binary package.
A relocatable program can be moved or copied to a different location on the file system. It is possible to make symlinks to the installed and moved programs, and invoke them through the symlink. It is possible to do the same thing with a hard link only if the hard link file is in the same directory as the real program.
The relocatable-prog
module aims to ease the process of making a
GNU program relocatable. It helps overcome two obstacles. First, it aids
with relocating the hard-coded references to absolute file names that
GNU programs often contain. These references must be fixed up at
runtime if a program is to be successfully relocated. The
relocatable-prog
module provides a function relocate
that
does this job.
Second, the loader must be able to find shared libraries linked to
relocatable executables or referenced by other shared libraries linked
to relocatable executables. The relocatable-prog
module helps out
here in a platform-specific way:
LD_LIBRARY_PATH
) and then invokes the real executable.
This applies to operating systems such as AIX, HP-UX, or Minix.
You can make your program relocatable by following these steps:
relocatable-prog
module. For libraries, use the
relocatable-lib
or relocatable-lib-lgpl
module, if
the libraries are independent. For installing multiple libraries,
at least one of which depends on another one, use the relocatable-prog
module.
If you need more than one module, or you need to use them with different
settings, you will need multiple copies of gnulib (see Using Gnulib for both a library and a program).
main
as the first statement (even
before setting the locale or doing anything related to libintl):
set_program_name (argv[0]);
The prototype for this function is in progname.h.
set_relocation_prefix
.
relocate
so it gets translated to the run-time situation.
Example:
bindtextdomain (PACKAGE, LOCALEDIR);
becomes:
bindtextdomain (PACKAGE, relocate (LOCALEDIR));
The prototype for this function is in relocatable.h.
There is also a variant of this function, named relocate2
, that
makes it easy to reclaim the memory allocated by the call.
set_program_name
function can also configure some
additional libraries to relocate files that they access, by defining
corresponding C preprocessor symbols to 1. The libraries for which
this is supported and the corresponding preprocessor symbols are:
DEPENDS_ON_LIBCHARSET
DEPENDS_ON_LIBICONV
DEPENDS_ON_LIBINTL
Defining the symbol for a library makes every program in the package depend on that library, whether the program really uses the library or not, so this feature should be used with some caution.
relocatable-script
module. Then, near the beginning of each
shell script that your package installs, add the following:
@relocatable_sh@ prefix="@prefix@" exec_prefix="@exec_prefix@" # usually needs $prefix. datarootdir="@datarootdir@" # usually needs $prefix. if test "@RELOCATABLE@" = yes; then bindir="@bindir@" orig_installdir="$bindir" # see Makefile.am's *_SCRIPTS variables func_find_curr_installdir # determine curr_installdir func_find_prefixes relocate () { echo "$1/" \ | sed -e "s%^${orig_installprefix}/%${curr_installprefix}/%" \ | sed -e 's,/$,,' } else relocate () { echo "$1" } fi # Get some relocated directory names. sysconfdir=`relocate "@sysconfdir@"` # usually needs $prefix. some_datadir=`relocate "@datadir@/something"` # usually needs $datarootdir. bindir=`relocate "@bindir@"` # usually needs $exec_prefix, hence $prefix.
You must adapt the definition of orig_installdir
, depending on
where the script gets installed. Also, at the end, instead of
sysconfdir
and some_datadir
, transform those variables
that you need.
relocatable-perl
module. Then, near the beginning of each
Perl script that your package installs, add the following:
@relocatable_pl@ if ("@RELOCATABLE@" eq "yes") { my $exec_prefix = "@exec_prefix@"; my $orig_installdir = "@bindir@"; # see Makefile.am's *_SCRIPTS variables my ($orig_installprefix, $curr_installprefix) = find_prefixes($orig_installdir, find_curr_installdir()); # the subroutine is defined whether or not the enclosing block is executed sub relocate { my ($dir) = @_; if ("@RELOCATABLE@" eq "yes") { $dir =~ s%^$orig_installprefix/%$curr_installprefix/%; $dir =~ s,/$,,; } return $dir; } } # Get some relocated directory names. # (The gnulib module 'configmake' can help with this.) $sysconfdir = relocate("@sysconfdir@"); $some_datadir = relocate(@datadir@/something");
You must adapt the definition of $orig_installdir
, depending on
where the script gets installed. Also, at the end, instead of
sysconfdir
and some_datadir
, transform those variables
that you need.
foo
that gets
installed in, say, $(bindir), you add:
foo_CPPFLAGS = -DINSTALLDIR=\"$(bindir)\" if RELOCATABLE_VIA_LD foo_LDFLAGS = `$(RELOCATABLE_LDFLAGS) $(bindir)` endif
When building gnulib to use with a relocatable library, you need to
define the preprocessor symbol IN_LIBRARY
.
You may also want to build with ENABLE_COSTLY_RELOCATABLE
, in which case
you will also need to define INSTALLDIR
.
The following fragment can be added to an override Makefile.am
used
to build gnulib (see Modifying the build rules of a Gnulib import directory).
AM_CPPFLAGS += -DIN_LIBRARY -DENABLE_COSTLY_RELOCATABLE if SHLIBS_IN_BINDIR AM_CPPFLAGS += -DINSTALLDIR=\"$(bindir)\" else AM_CPPFLAGS += -DINSTALLDIR=\"$(libdir)\" endif
SHLIBS_IN_BINDIR
is defined in configure.ac as follows:
AM_CONDITIONAL([SHLIBS_IN_BINDIR], [case "$host_os" in mingw* | cygwin*) true;; *) false;; esac])
libfoo
that gets
installed in, say, $(libdir), you add:
if RELOCATABLE_VIA_LD libfoo_la_LDFLAGS = `$(RELOCATABLE_LDFLAGS) $(libdir)` endif
If your package (or any package you rely on, e.g. gettext-runtime)
will be relocated together with a set of installed shared libraries,
then set RELOCATABLE_LIBRARY_PATH
to a colon-separated list
of those libraries’ directories, e.g.
RELOCATABLE_LIBRARY_PATH = $(libdir)
If your config.h is not in $(top_builddir), then set
RELOCATABLE_CONFIG_H_DIR
to its directory, e.g.
RELOCATABLE_CONFIG_H_DIR = $(top_builddir)/src
The func
module makes sure that you can use the predefined
identifier __func__
as defined by C99 in your code.
A small example is:
#include <config.h> #include <stdio.h> /* for printf */ int main (void) { printf ("%s: hello world\n", __func__); }
Note that sizeof
cannot be applied to __func__
: On SunPRO C
compiler, sizeof __func__
evaluates to 0.
The stat-size
module provides a small number of macros
intended for interpreting the file size information in an instance of
struct stat
.
On POSIX systems, the st_blocks
member of struct stat
contains the number of disk blocks occupied by a file. The
ST_NBLOCKS
and STP_NBLOCKS
macros
estimate this quantity on systems
which don’t actually have st_blocks
. Each of these blocks
contains ST_NBLOCKSIZE
bytes.
The value of ST_NBLOCKSIZE
is often quite small, small enough
that performing I/O in chunks that size would be inefficient.
The ST_BLKSIZE
and STP_BLKSIZE
macros
give the I/O block size recommended for I/O to this
file. This is not guaranteed to give optimum performance, but it
should be reasonably efficient.
A regular expression (or regexp, or pattern) is a text string that describes some (mathematical) set of strings. A regexp r matches a string s if s is in the set of strings described by r.
Using the Regex library, you can:
Some regular expressions match only one string, i.e., the set they describe has only one member. For example, the regular expression ‘foo’ matches the string ‘foo’ and no others. Other regular expressions match more than one string, i.e., the set they describe has more than one member. For example, the regular expression ‘f*’ matches the set of strings made up of any number (including zero) of ‘f’s. As you can see, some characters in regular expressions match themselves (such as ‘f’) and some don’t (such as ‘*’); the ones that don’t match themselves instead let you specify patterns that describe many different strings.
To either match or search for a regular expression with the Regex library functions, you must first compile it with a Regex pattern compiling function. A compiled pattern is a regular expression converted to the internal format used by the library functions. Once you’ve compiled a pattern, you can use it for matching or searching any number of times.
The Regex library is used by including regex.h. Regex provides three groups of functions with which you can operate on regular expressions. One group—the GNU group—is more powerful but not completely compatible with the other two, namely the POSIX and Berkeley Unix groups; its interface was designed specifically for GNU.
We wrote this chapter with programmers in mind, not users of programs—such as Emacs—that use Regex. We describe the Regex library in its entirety, not how to write regular expressions that a particular program understands.
Characters are things you can type. Operators are things in a regular expression that match one or more characters. You compose regular expressions from operators, which in turn you specify using one or more characters.
Most characters represent what we call the match-self operator, i.e., they match themselves; we call these characters ordinary. Other characters represent either all or parts of fancier operators; e.g., ‘.’ represents what we call the match-any-character operator (which, no surprise, matches (almost) any character); we call these characters special. Two different things determine what characters represent what operators:
In the following sections, we describe these things in more detail.
In any particular syntax for regular expressions, some characters are
always special, others are sometimes special, and others are never
special. The particular syntax that Regex recognizes for a given
regular expression depends on the current syntax (as set by
re_set_syntax
) when the pattern buffer of that regular expression
was compiled.
You get a pattern buffer by compiling a regular expression. See GNU Pattern Buffers, for more information on pattern buffers. See GNU Regular Expression Compiling, and BSD Regular Expression Compiling, for more information on compiling.
Regex considers the current syntax to be a collection of bits; we refer to these bits as syntax bits. In most cases, they affect what characters represent what operators. We describe the meanings of the operators to which we refer in Common Operators and GNU Operators.
For reference, here is the complete list of syntax bits, in alphabetical order:
RE_BACKSLASH_ESCAPE_IN_LISTS
¶If this bit is set, then ‘\’ inside a list (see List Operators ([
… ]
and [^
… ]
))
quotes (makes ordinary, if it’s special) the following character; if
this bit isn’t set, then ‘\’ is an ordinary character inside lists.
(See The Backslash Character, for what ‘\’ does outside of lists.)
RE_BK_PLUS_QM
¶If this bit is set, then ‘\+’ represents the match-one-or-more
operator and ‘\?’ represents the match-zero-or-more operator; if
this bit isn’t set, then ‘+’ represents the match-one-or-more
operator and ‘?’ represents the match-zero-or-one operator. This
bit is irrelevant if RE_LIMITED_OPS
is set.
RE_CHAR_CLASSES
¶If this bit is set, then you can use character classes in lists; if this bit isn’t set, then you can’t.
RE_CONTEXT_INDEP_ANCHORS
¶If this bit is set, then ‘^’ and ‘$’ are special anywhere outside
a list; if this bit isn’t set, then these characters are special only in
certain contexts. See The Match-beginning-of-line Operator (^
), and
The Match-end-of-line Operator ($
).
RE_CONTEXT_INDEP_OPS
¶If this bit is set, then certain characters are special anywhere outside
a list; if this bit isn’t set, then those characters are special only in
some contexts and are ordinary elsewhere. Specifically, if this bit
isn’t set then ‘*’, and (if the syntax bit RE_LIMITED_OPS
isn’t set) ‘+’ and ‘?’ (or ‘\+’ and ‘\?’, depending
on the syntax bit RE_BK_PLUS_QM
) represent repetition operators
only if they’re not first in a regular expression or just after an
open-group or alternation operator. The same holds for ‘{’ (or
‘\{’, depending on the syntax bit RE_NO_BK_BRACES
) if
it is the beginning of a valid interval and the syntax bit
RE_INTERVALS
is set.
RE_CONTEXT_INVALID_DUP
¶If this bit is set, then an open-interval operator cannot occur at the start of a regular expression, or immediately after an alternation, open-group or close-interval operator.
RE_CONTEXT_INVALID_OPS
¶If this bit is set, then repetition and alternation operators can’t be in certain positions within a regular expression. Specifically, the regular expression is invalid if it has:
If this bit isn’t set, then you can put the characters representing the repetition and alternation characters anywhere in a regular expression. Whether or not they will in fact be operators in certain positions depends on other syntax bits.
RE_DEBUG
¶If this bit is set, and the regex library was compiled with
-DDEBUG
, then internal debugging is turned on; if unset, then
it is turned off.
RE_DOT_NEWLINE
¶If this bit is set, then the match-any-character operator matches a newline; if this bit isn’t set, then it doesn’t.
RE_DOT_NOT_NULL
¶If this bit is set, then the match-any-character operator doesn’t match a null character; if this bit isn’t set, then it does.
RE_HAT_LISTS_NOT_NEWLINE
¶If this bit is set, nonmatching lists ‘[^...]’ do not match newline; if not set, they do.
RE_ICASE
¶If this bit is set, then ignore case when matching; otherwise, case is significant.
RE_INTERVALS
¶If this bit is set, then Regex recognizes interval operators; if this bit isn’t set, then it doesn’t.
RE_INVALID_INTERVAL_ORD
¶If this bit is set, a syntactically invalid interval is treated as a string of ordinary characters. For example, the extended regular expression ‘a{1’ is treated as ‘a\{1’.
RE_LIMITED_OPS
¶If this bit is set, then Regex doesn’t recognize the match-one-or-more, match-zero-or-one or alternation operators; if this bit isn’t set, then it does.
RE_NEWLINE_ALT
¶If this bit is set, then newline represents the alternation operator; if this bit isn’t set, then newline is ordinary.
RE_NO_BK_BRACES
¶If this bit is set, then ‘{’ represents the open-interval operator
and ‘}’ represents the close-interval operator; if this bit isn’t
set, then ‘\{’ represents the open-interval operator and
‘\}’ represents the close-interval operator. This bit is relevant
only if RE_INTERVALS
is set.
RE_NO_BK_PARENS
¶If this bit is set, then ‘(’ represents the open-group operator and ‘)’ represents the close-group operator; if this bit isn’t set, then ‘\(’ represents the open-group operator and ‘\)’ represents the close-group operator.
RE_NO_BK_REFS
¶If this bit is set, then Regex doesn’t recognize ‘\’digit as the back-reference operator; if this bit isn’t set, then it does.
RE_NO_BK_VBAR
¶If this bit is set, then ‘|’ represents the alternation operator;
if this bit isn’t set, then ‘\|’ represents the alternation
operator. This bit is irrelevant if RE_LIMITED_OPS
is set.
RE_NO_EMPTY_RANGES
¶If this bit is set, then a regular expression with a range whose ending point collates lower than its starting point is invalid; if this bit isn’t set, then Regex considers such a range to be empty.
RE_NO_GNU_OPS
¶If this bit is set, GNU regex operators are not recognized; otherwise, they are.
RE_NO_POSIX_BACKTRACKING
¶If this bit is set, succeed as soon as we match the whole pattern, without further backtracking. This means that a match may not be the leftmost longest; see What Gets Matched? for what this means.
RE_NO_SUB
¶If this bit is set, then no_sub
will be set to one during
re_compile_pattern
. This causes matching and searching routines
not to record substring match information.
RE_UNMATCHED_RIGHT_PAREN_ORD
¶If this bit is set and the regular expression has no matching open-group
operator, then Regex considers what would otherwise be a close-group
operator (based on how RE_NO_BK_PARENS
is set) to match ‘)’.
If you’re programming with Regex, you can set a pattern buffer’s (see GNU Pattern Buffers) syntax either to an arbitrary combination of syntax bits (see Syntax Bits) or else to the configurations defined by Regex. These configurations define the syntaxes used by certain programs—GNU Emacs, POSIX Awk, traditional Awk, Grep, Egrep—in addition to syntaxes for POSIX basic and extended regular expressions.
The predefined syntaxes—taken directly from regex.h—are:
#define RE_SYNTAX_EMACS 0 #define RE_SYNTAX_AWK \ (RE_BACKSLASH_ESCAPE_IN_LISTS | RE_DOT_NOT_NULL \ | RE_NO_BK_PARENS | RE_NO_BK_REFS \ | RE_NO_BK_VBAR | RE_NO_EMPTY_RANGES \ | RE_UNMATCHED_RIGHT_PAREN_ORD) #define RE_SYNTAX_POSIX_AWK \ (RE_SYNTAX_POSIX_EXTENDED | RE_BACKSLASH_ESCAPE_IN_LISTS) #define RE_SYNTAX_GREP \ (RE_BK_PLUS_QM | RE_CHAR_CLASSES \ | RE_HAT_LISTS_NOT_NEWLINE | RE_INTERVALS \ | RE_NEWLINE_ALT) #define RE_SYNTAX_EGREP \ (RE_CHAR_CLASSES | RE_CONTEXT_INDEP_ANCHORS \ | RE_CONTEXT_INDEP_OPS | RE_HAT_LISTS_NOT_NEWLINE \ | RE_NEWLINE_ALT | RE_NO_BK_PARENS \ | RE_NO_BK_VBAR) #define RE_SYNTAX_POSIX_EGREP \ (RE_SYNTAX_EGREP | RE_INTERVALS | RE_NO_BK_BRACES) /* P1003.2/D11.2, section 4.20.7.1, lines 5078ff. */ #define RE_SYNTAX_ED RE_SYNTAX_POSIX_BASIC #define RE_SYNTAX_SED RE_SYNTAX_POSIX_BASIC /* Syntax bits common to both basic and extended POSIX regex syntax. */ #define _RE_SYNTAX_POSIX_COMMON \ (RE_CHAR_CLASSES | RE_DOT_NEWLINE | RE_DOT_NOT_NULL \ | RE_INTERVALS | RE_NO_EMPTY_RANGES) #define RE_SYNTAX_POSIX_BASIC \ (_RE_SYNTAX_POSIX_COMMON | RE_BK_PLUS_QM) /* Differs from ..._POSIX_BASIC only in that RE_BK_PLUS_QM becomes RE_LIMITED_OPS, i.e., \? \+ \| are not recognized. Actually, this isn't minimal, since other operators, such as \`, aren't disabled. */ #define RE_SYNTAX_POSIX_MINIMAL_BASIC \ (_RE_SYNTAX_POSIX_COMMON | RE_LIMITED_OPS) #define RE_SYNTAX_POSIX_EXTENDED \ (_RE_SYNTAX_POSIX_COMMON | RE_CONTEXT_INDEP_ANCHORS \ | RE_CONTEXT_INDEP_OPS | RE_NO_BK_BRACES \ | RE_NO_BK_PARENS | RE_NO_BK_VBAR \ | RE_UNMATCHED_RIGHT_PAREN_ORD) /* Differs from ..._POSIX_EXTENDED in that RE_CONTEXT_INVALID_OPS replaces RE_CONTEXT_INDEP_OPS and RE_NO_BK_REFS is added. */ #define RE_SYNTAX_POSIX_MINIMAL_EXTENDED \ (_RE_SYNTAX_POSIX_COMMON | RE_CONTEXT_INDEP_ANCHORS \ | RE_CONTEXT_INVALID_OPS | RE_NO_BK_BRACES \ | RE_NO_BK_PARENS | RE_NO_BK_REFS \ | RE_NO_BK_VBAR | RE_UNMATCHED_RIGHT_PAREN_ORD)
POSIX generalizes the notion of a character to that of a collating element. It defines a collating element to be “a sequence of one or more bytes defined in the current collating sequence as a unit of collation.”
This generalizes the notion of a character in two ways. First, a single character can map into two or more collating elements. For example, the German “ß” collates as the collating element ‘s’ followed by another collating element ‘s’. Second, two or more characters can map into one collating element. For example, the Czech ‘ch’ collates after ‘h’ and before ‘i’.
Since POSIX’s “collating element” preserves the essential idea of a “character,” we use the latter, more familiar, term in this document.
The ‘\’ character has one of four different meanings, depending on the context in which you use it and what syntax bits are set (see Syntax Bits). It can: 1) stand for itself, 2) quote the next character, 3) introduce an operator, or 4) do nothing.
[
… ]
and [^
… ]
)) if the syntax bit
RE_BACKSLASH_ESCAPE_IN_LISTS
is not set. For example, ‘[\]’
would match ‘\’.
RE_BACKSLASH_ESCAPE_IN_LISTS
is set.
RE_BK_PLUS_QM
, RE_NO_BK_BRACES
, RE_NO_BK_VAR
,
RE_NO_BK_PARENS
, RE_NO_BK_REF
in Syntax Bits. Also:
\b
)).
\B
)).
\<
)).
\>
)).
\w
)).
\W
)).
[[:space:]]
(see The Match-space Operator (\s
)).
[^[:space]]
(see The Match-non-space Operator (\S
)).
You compose regular expressions from operators. In the following sections, we describe the regular expression operators specified by POSIX; GNU also uses these. Most operators have more than one representation as characters. See Regular Expression Syntax, for what characters represent what operators under what circumstances.
For most operators that can be represented in two ways, one
representation is a single character and the other is that character
preceded by ‘\’. For example, either ‘(’ or ‘\(’
represents the open-group operator. Which one does depends on the
setting of a syntax bit, in this case RE_NO_BK_PARENS
. Why is
this so? Historical reasons dictate some of the varying
representations, while POSIX dictates others.
Finally, almost all characters lose any special meaning inside a list
(see List Operators ([
… ]
and [^
… ]
)).
.
)|
or \|
)[
… ]
and [^
… ]
)(
… )
or \(
… \)
)This operator matches the character itself. All ordinary characters (see Regular Expression Syntax) represent this operator. For example, ‘f’ is always an ordinary character, so the regular expression ‘f’ matches only the string ‘f’. In particular, it does not match the string ‘ff’.
.
) ¶This operator matches any single printing or nonprinting character except it won’t match a:
if the syntax bit RE_DOT_NEWLINE
isn’t set.
if the syntax bit RE_DOT_NOT_NULL
is set.
The ‘.’ (period) character represents this operator. For example, ‘a.b’ matches any three-character string beginning with ‘a’ and ending with ‘b’.
This operator concatenates two regular expressions a and b. No character represents this operator; you simply put b after a. The result is a regular expression that will match a string if a matches its first part and b matches the rest. For example, ‘xy’ (two match-self operators) matches ‘xy’.
Repetition operators repeat the preceding regular expression a specified number of times.
*
)+
or \+
)?
or \?
){
… }
or \{
… \}
)*
) ¶This operator repeats the smallest possible preceding regular expression as many times as necessary (including zero) to match the pattern. ‘*’ represents this operator. For example, ‘o*’ matches any string made up of zero or more ‘o’s. Since this operator operates on the smallest preceding regular expression, ‘fo*’ has a repeating ‘o’, not a repeating ‘fo’. So, ‘fo*’ matches ‘f’, ‘fo’, ‘foo’, and so on.
Since the match-zero-or-more operator is a suffix operator, it may be useless as such when no regular expression precedes it. This is the case when it:
Three different things can happen in these cases:
RE_CONTEXT_INVALID_OPS
is set, then the
regular expression is invalid.
RE_CONTEXT_INVALID_OPS
isn’t set, but
RE_CONTEXT_INDEP_OPS
is, then ‘*’ represents the
match-zero-or-more operator (which then operates on the empty string).
The matcher processes a match-zero-or-more operator by first matching as many repetitions of the smallest preceding regular expression as it can. Then it continues to match the rest of the pattern.
If it can’t match the rest of the pattern, it backtracks (as many times as necessary), each time discarding one of the matches until it can either match the entire pattern or be certain that it cannot get a match. For example, when matching ‘ca*ar’ against ‘caaar’, the matcher first matches all three ‘a’s of the string with the ‘a*’ of the regular expression. However, it cannot then match the final ‘ar’ of the regular expression against the final ‘r’ of the string. So it backtracks, discarding the match of the last ‘a’ in the string. It can then match the remaining ‘ar’.
+
or \+
) ¶If the syntax bit RE_LIMITED_OPS
is set, then Regex doesn’t recognize
this operator. Otherwise, if the syntax bit RE_BK_PLUS_QM
isn’t
set, then ‘+’ represents this operator; if it is, then ‘\+’
does.
This operator is similar to the match-zero-or-more operator except that
it repeats the preceding regular expression at least once;
see The Match-zero-or-more Operator (*
), for what it operates on, how some
syntax bits affect it, and how Regex backtracks to match it.
For example, supposing that ‘+’ represents the match-one-or-more operator; then ‘ca+r’ matches, e.g., ‘car’ and ‘caaaar’, but not ‘cr’.
?
or \?
) ¶If the syntax bit RE_LIMITED_OPS
is set, then Regex doesn’t
recognize this operator. Otherwise, if the syntax bit
RE_BK_PLUS_QM
isn’t set, then ‘?’ represents this operator;
if it is, then ‘\?’ does.
This operator is similar to the match-zero-or-more operator except that
it repeats the preceding regular expression once or not at all;
see The Match-zero-or-more Operator (*
), to see what it operates on, how
some syntax bits affect it, and how Regex backtracks to match it.
For example, supposing that ‘?’ represents the match-zero-or-one operator; then ‘ca?r’ matches both ‘car’ and ‘cr’, but nothing else.
{
… }
or \{
… \}
) ¶If the syntax bit RE_INTERVALS
is set, then Regex recognizes
interval expressions. They repeat the smallest possible preceding
regular expression a specified number of times.
If the syntax bit RE_NO_BK_BRACES
is set, ‘{’ represents
the open-interval operator and ‘}’ represents the
close-interval operator ; otherwise, ‘\{’ and ‘\}’ do.
Specifically, supposing that ‘{’ and ‘}’ represent the open-interval and close-interval operators; then:
{count}
matches exactly count occurrences of the preceding regular expression.
{min,}
matches min or more occurrences of the preceding regular expression.
{min, max}
matches at least min but no more than max occurrences of the preceding regular expression.
The interval expression (but not necessarily the regular expression that contains it) is invalid if:
RE_DUP_MAX
(which symbol regex.h
defines).
If the interval expression is invalid and the syntax bit
RE_NO_BK_BRACES
is set, then Regex considers all the
characters in the would-be interval to be ordinary. If that bit
isn’t set, then the regular expression is invalid.
If the interval expression is valid but there is no preceding regular
expression on which to operate, then if the syntax bit
RE_CONTEXT_INVALID_OPS
is set, the regular expression is invalid.
If that bit isn’t set, then Regex considers all the characters—other
than backslashes, which it ignores—in the would-be interval to be
ordinary.
|
or \|
) ¶If the syntax bit RE_LIMITED_OPS
is set, then Regex doesn’t
recognize this operator. Otherwise, if the syntax bit
RE_NO_BK_VBAR
is set, then ‘|’ represents this operator;
otherwise, ‘\|’ does.
Alternatives match one of a choice of regular expressions: if you put the character(s) representing the alternation operator between any two regular expressions a and b, the result matches the union of the strings that a and b match. For example, supposing that ‘|’ is the alternation operator, then ‘foo|bar|quux’ would match any of ‘foo’, ‘bar’ or ‘quux’.
The alternation operator operates on the largest possible surrounding regular expressions. (Put another way, it has the lowest precedence of any regular expression operator.) Thus, the only way you can delimit its arguments is to use grouping. For example, if ‘(’ and ‘)’ are the open and close-group operators, then ‘fo(o|b)ar’ would match either ‘fooar’ or ‘fobar’. (‘foo|bar’ would match ‘foo’ or ‘bar’.)
The matcher usually tries all combinations of alternatives so as to match the longest possible string. For example, when matching ‘(fooq|foo)*(qbarquux|bar)’ against ‘fooqbarquux’, it cannot take, say, the first (“depth-first”) combination it could match, since then it would be content to match just ‘fooqbar’.
Note that since the default behavior is to return the leftmost longest match, when more than one of a series of alternatives matches the actual match will be the longest matching alternative, not necessarily the first in the list.
[
… ]
and [^
… ]
) ¶Lists, also called bracket expressions, are a set of one or more items. An item is a character, a collating symbol, an equivalence class expression, a character class expression, or a range expression. The syntax bits affect which kinds of items you can put in a list. We explain the last four items in subsections below. Empty lists are invalid.
A matching list matches a single character represented by one of the list items. You form a matching list by enclosing one or more items within an open-matching-list operator (represented by ‘[’) and a close-list operator (represented by ‘]’).
For example, ‘[ab]’ matches either ‘a’ or ‘b’. ‘[ad]*’ matches the empty string and any string composed of just ‘a’s and ‘d’s in any order. Regex considers invalid a regular expression with a ‘[’ but no matching ‘]’.
Nonmatching lists are similar to matching lists except that they match a single character not represented by one of the list items. You use an open-nonmatching-list operator (represented by ‘[^’4) instead of an open-matching-list operator to start a nonmatching list.
For example, ‘[^ab]’ matches any character except ‘a’ or ‘b’.
If the syntax bit RE_HAT_LISTS_NOT_NEWLINE
is set, then
nonmatching lists do not match a newline.
Most characters lose any special meaning inside a list. The special characters inside a list follow.
ends the list if it’s not the first list item. So, if you want to make the ‘]’ character a list item, you must put it first.
quotes the next character if the syntax bit RE_BACKSLASH_ESCAPE_IN_LISTS
is
set.
represents the open-collating-symbol operator (see Collating Symbol Operators ([.
… .]
)).
represents the close-collating-symbol operator.
represents the open-equivalence-class operator (see Equivalence Class Operators ([=
… =]
)).
represents the close-equivalence-class operator.
represents the open-character-class operator (see Character Class Operators ([:
… :]
)) if the syntax bit RE_CHAR_CLASSES
is set and what
follows is a valid character class expression.
represents the close-character-class operator if the syntax bit
RE_CHAR_CLASSES
is set and what precedes it is an
open-character-class operator followed by a valid character class name.
represents the range operator (see The Range Operator (-
)) if it’s
not first or last in a list or the ending point of a range.
All other characters are ordinary. For example, ‘[.*]’ matches ‘.’ and ‘*’.
[.
… .]
)[=
… =]
)[:
… :]
)-
)[.
… .]
) ¶Collating symbols can be represented inside lists. You form a collating symbol by putting a collating element between an open-collating-symbol operator and a close-collating-symbol operator. ‘[.’ represents the open-collating-symbol operator and ‘.]’ represents the close-collating-symbol operator. For example, if ‘ll’ is a collating element, then ‘[[.ll.]]’ would match ‘ll’.
[=
… =]
) ¶Regex recognizes equivalence class expressions inside lists. A equivalence class expression is a set of collating elements which all belong to the same equivalence class. You form an equivalence class expression by putting a collating element between an open-equivalence-class operator and a close-equivalence-class operator. ‘[=’ represents the open-equivalence-class operator and ‘=]’ represents the close-equivalence-class operator. For example, if ‘a’ and ‘A’ were an equivalence class, then both ‘[[=a=]]’ and ‘[[=A=]]’ would match both ‘a’ and ‘A’. If the collating element in an equivalence class expression isn’t part of an equivalence class, then the matcher considers the equivalence class expression to be a collating symbol.
[:
… :]
) ¶If the syntax bit RE_CHAR_CLASSES
is set, then Regex recognizes
character class expressions inside lists. A character class
expression matches one character from a given class. You form a
character class expression by putting a character class name between
an open-character-class operator (represented by ‘[:’) and
a close-character-class operator (represented by ‘:]’).
The character class names and their meanings are:
alnum
letters and digits
alpha
letters
blank
system-dependent; for GNU, a space or tab
cntrl
control characters (in the ASCII encoding, code 0177 and codes less than 040)
digit
digits
graph
same as print
except omits space
lower
lowercase letters
print
printable characters (in the ASCII encoding, space tilde—codes 040 through 0176)
punct
neither control nor alphanumeric characters
space
space, carriage return, newline, vertical tab, and form feed
upper
uppercase letters
xdigit
hexadecimal digits: 0
–9
, a
–f
, A
–F
These correspond to the definitions in the C library’s <ctype.h>
facility. For example, ‘[:alpha:]’ corresponds to the standard
facility isalpha
. Regex recognizes character class expressions
only inside of lists; so ‘[[:alpha:]]’ matches any letter, but
‘[:alpha:]’ outside of a bracket expression and not followed by a
repetition operator matches just itself.
-
) ¶Regex recognizes range expressions inside a list. They represent those characters that fall between two elements in the current collating sequence. You form a range expression by putting a range operator between two of any of the following: characters, collating elements, collating symbols, and equivalence class expressions. The starting point of the range and the ending point of the range don’t have to be the same kind of item, e.g., the starting point could be a collating element and the ending point could be an equivalence class expression. If a range’s ending point is an equivalence class, then all the collating elements in that class will be in the range.5 ‘-’ represents the range operator. For example, ‘a-f’ within a list represents all the characters from ‘a’ through ‘f’ inclusively.
If the syntax bit RE_NO_EMPTY_RANGES
is set, then if the range’s
ending point collates less than its starting point, the range (and the
regular expression containing it) is invalid. For example, the regular
expression ‘[z-a]’ would be invalid. If this bit isn’t set, then
Regex considers such a range to be empty.
Since ‘-’ represents the range operator, if you want to make a ‘-’ character itself a list item, you must do one of the following:
For example, ‘[-a-z]’ matches a lowercase letter or a hyphen (in English, in ASCII).
(
… )
or \(
… \)
) ¶A group, also known as a subexpression, consists of an open-group operator, any number of other operators, and a close-group operator. Regex treats this sequence as a unit, just as mathematics and programming languages treat a parenthesized expression as a unit.
Therefore, using groups, you can:
|
or \|
)) or a repetition operator (see Repetition Operators).
If the syntax bit RE_NO_BK_PARENS
is set, then ‘(’ represents
the open-group operator and ‘)’ represents the
close-group operator; otherwise, ‘\(’ and ‘\)’ do.
If the syntax bit RE_UNMATCHED_RIGHT_PAREN_ORD
is set and a
close-group operator has no matching open-group operator, then Regex
considers it to match ‘)’.
If the syntax bit RE_NO_BK_REF
isn’t set, then Regex recognizes
back-references. A back-reference matches a specified preceding group.
The back-reference operator is represented by ‘\digit’
anywhere after the end of a regular expression’s digit-th
group (see Grouping Operators ((
… )
or \(
… \)
)).
digit must be between ‘1’ and ‘9’. The matcher assigns numbers 1 through 9 to the first nine groups it encounters. By using one of ‘\1’ through ‘\9’ after the corresponding group’s close-group operator, you can match a substring identical to the one that the group does.
Back-references match according to the following (in all examples below, ‘(’ represents the open-group, ‘)’ the close-group, ‘{’ the open-interval and ‘}’ the close-interval operator):
RE_DOT_NEWLINE
isn’t set) string that is composed of two
identical halves; the ‘(.*)’ matches the first half and the
‘\1’ matches the second half.
You can use a back-reference as an argument to a repetition operator. For example, ‘(a(b))\2*’ matches ‘a’ followed by two or more ‘b’s. Similarly, ‘(a(b))\2{3}’ matches ‘abbbb’.
If there is no preceding digit-th subexpression, the regular expression is invalid.
Back-references can greatly slow down matching, as they can generate exponentially many matching possibilities that can consume both time and memory to explore. Also, the POSIX specification for back-references is at times unclear. Furthermore, many regular expression implementations have back-reference bugs that can cause programs to return incorrect answers or even crash, and fixing these bugs has often been low-priority: for example, as of 2020 the GNU C library bug database contained back-reference bugs 52, 10844, 11053, 24269 and 25322, with little sign of forthcoming fixes. Luckily, back-references are rarely useful and it should be little trouble to avoid them in practical applications.
These operators can constrain a pattern to match only at the beginning or end of the entire string or at the beginning or end of a line.
^
) ¶This operator can match the empty string either at the beginning of the string or after a newline character. Thus, it is said to anchor the pattern to the beginning of a line.
In the cases following, ‘^’ represents this operator. (Otherwise, ‘^’ is ordinary.)
RE_CONTEXT_INDEP_ANCHORS
is set, and it is outside
a bracket expression.
(
… )
or \(
… \)
), and The Alternation Operator (|
or \|
).
These rules imply that some valid patterns containing ‘^’ cannot be
matched; for example, ‘foo^bar’ if RE_CONTEXT_INDEP_ANCHORS
is set.
If the not_bol
field is set in the pattern buffer (see GNU Pattern Buffers), then ‘^’ fails to match at the beginning of the
string. This lets you match against pieces of a line, as you would need to if,
say, searching for repeated instances of a given pattern in a line; it
would work correctly for patterns both with and without
match-beginning-of-line operators.
$
) ¶This operator can match the empty string either at the end of the string or before a newline character in the string. Thus, it is said to anchor the pattern to the end of a line.
It is always represented by ‘$’. For example, ‘foo$’ usually matches, e.g., ‘foo’ and, e.g., the first three characters of ‘foo\nbar’.
Its interaction with the syntax bits and pattern buffer fields is
exactly the dual of ‘^’’s; see the previous section. (That is,
“‘^’” becomes “‘$’”, “beginning” becomes “end”,
“next” becomes “previous”, “after” becomes “before”, and
“not_bol
” becomes “not_eol
”.)
The following are operators that GNU defines (and POSIX doesn’t) that
you can use unless the syntax bit RE_NO_GNU_OPS
is set.
The operators in this section require Regex to recognize parts of words.
Characters that are part of words, which are called
word-constituent, are letters, digits, and the underscore
(‘_’); more precisely, any character in the POSIX class
alnum
in the current locale, or underscore.
\b
)\B
)\<
)\>
)\w
)\W
)\b
) ¶This operator (represented by ‘\b’) matches the empty string at either the beginning or the end of a word. For example, ‘\brat\b’ matches the separate word ‘rat’.
\B
) ¶This operator (represented by ‘\B’) matches the empty string within a word. For example, ‘c\Brat\Be’ matches ‘crate’, but ‘dirty \Brat’ doesn’t match ‘dirty rat’.
\<
) ¶This operator (represented by ‘\<’) matches the empty string at the beginning of a word.
\>
) ¶This operator (represented by ‘\>’) matches the empty string at the end of a word.
\w
) ¶This operator (represented by ‘\w’) matches any word-constituent character.
\W
) ¶This operator (represented by ‘\W’) matches any character that is not word-constituent.
\s
) ¶This operator (represented by ‘\s’) matches any space
character (that is, in the POSIX class [:space:]
).
\S
) ¶This operator (represented by ‘\S’) matches any character
that is not a space (that is, in the POSIX class [:space:]
).
Following are operators which work on the whole string.
\`
) ¶This operator (represented by ‘\`’) matches the empty string at the beginning of the string.
\'
) ¶This operator (represented by ‘\'’) matches the empty string at the end of the string.
Regex usually matches strings according to the “leftmost longest” rule; that is, it chooses the longest of the leftmost matches. This does not mean that for a regular expression containing subexpressions that it simply chooses the longest match for each subexpression, left to right; the overall match must also be the longest possible one.
For example, ‘(ac*)(c*d[ac]*)\1’ matches ‘acdacaaa’, not ‘acdac’, as it would if it were to choose the longest match for the first subexpression.
Here we describe how you use the Regex data structures and functions in C programs. Regex has three interfaces: one designed for GNU, one compatible with POSIX (as specified by POSIX, draft 1003.2/D11.2), and one compatible with Berkeley Unix. The POSIX interface is not documented here; see the documentation of GNU libc, or the POSIX man pages. The Berkeley Unix interface is documented here for convenience, since its documentation is not otherwise readily available on GNU systems.
If you’re writing code that doesn’t need to be compatible with either POSIX or Berkeley Unix, you can use these functions. They provide more options than the other interfaces.
To compile, match, or search for a given regular expression, you must supply a pattern buffer. A pattern buffer holds one compiled regular expression.6
You can have several different pattern buffers simultaneously, each holding a compiled pattern for a different regular expression.
regex.h defines the pattern buffer struct
with the
following public fields:
unsigned char *buffer; unsigned long allocated; char *fastmap; char *translate; size_t re_nsub; unsigned no_sub : 1; unsigned not_bol : 1; unsigned not_eol : 1;
In GNU, you can both match and search for a given regular expression. To do either, you must first compile it in a pattern buffer (see GNU Pattern Buffers).
Regular expressions match according to the syntax with which they were
compiled; with GNU, you indicate what syntax you want by setting
the variable re_syntax_options
(declared in regex.h)
before calling the compiling function, re_compile_pattern
(see
below). See Syntax Bits, and Predefined Syntaxes.
You can change the value of re_syntax_options
at any time.
Usually, however, you set its value once and then never change it.
re_compile_pattern
takes a pattern buffer as an argument. You
must initialize the following fields:
translate initialization
translate
¶Initialize this to point to a translate table if you want one, or to zero if you don’t. We explain translate tables in GNU Translate Tables.
fastmap
¶Initialize this to nonzero if you want a fastmap, or to zero if you don’t.
buffer
¶allocated
If you want re_compile_pattern
to allocate memory for the
compiled pattern, set both of these to zero. If you have an existing
block of memory (allocated with malloc
) you want Regex to use,
set buffer
to its address and allocated
to its size (in
bytes).
re_compile_pattern
uses realloc
to extend the space for
the compiled pattern as necessary.
To compile a pattern buffer, use:
char * re_compile_pattern (const char *regex, const int regex_size, struct re_pattern_buffer *pattern_buffer)
regex is the regular expression’s address, regex_size is its length, and pattern_buffer is the pattern buffer’s address.
If re_compile_pattern
successfully compiles the regular
expression, it returns zero and sets *pattern_buffer
to the
compiled pattern. It sets the pattern buffer’s fields as follows:
buffer
¶to the compiled pattern.
syntax
¶to the current value of re_syntax_options
.
re_nsub
¶to the number of subexpressions in regex.
If re_compile_pattern
can’t compile regex, it returns an
error string corresponding to a POSIX error code.
Matching the GNU way means trying to match as much of a string as possible starting at a position within it you specify. Once you’ve compiled a pattern into a pattern buffer (see GNU Regular Expression Compiling), you can ask the matcher to match that pattern against a string using:
int re_match (struct re_pattern_buffer *pattern_buffer, const char *string, const int size, const int start, struct re_registers *regs)
pattern_buffer is the address of a pattern buffer containing a compiled pattern. string is the string you want to match; it can contain newline and null characters. size is the length of that string. start is the string index at which you want to begin matching; the first character of string is at index zero. See Using Registers, for an explanation of regs; you can safely pass zero.
re_match
matches the regular expression in pattern_buffer
against the string string according to the syntax of
pattern_buffer. (See GNU Regular Expression Compiling, for how
to set it.) The function returns -1 if the compiled pattern does
not match any part of string and -2 if an internal error
happens; otherwise, it returns how many (possibly zero) characters of
string the pattern matched.
An example: suppose pattern_buffer points to a pattern buffer
containing the compiled pattern for ‘a*’, and string points
to ‘aaaaab’ (whereupon size should be 6). Then if start
is 2, re_match
returns 3, i.e., ‘a*’ would have matched the
last three ‘a’s in string. If start is 0,
re_match
returns 5, i.e., ‘a*’ would have matched all the
‘a’s in string. If start is either 5 or 6, it returns
zero.
If start is not between zero and size, then
re_match
returns -1.
Searching means trying to match starting at successive positions
within a string. The function re_search
does this.
Before calling re_search
, you must compile your regular
expression. See GNU Regular Expression Compiling.
Here is the function declaration:
int re_search (struct re_pattern_buffer *pattern_buffer, const char *string, const int size, const int start, const int range, struct re_registers *regs)
whose arguments are the same as those to re_match
(see GNU Matching) except that the two arguments start and range
replace re_match
’s argument start.
If range is positive, then re_search
attempts a match
starting first at index start, then at start + 1 if
that fails, and so on, up to start + range; if
range is negative, then it attempts a match starting first at
index start, then at start -1 if that fails, and so
on.
If start is not between zero and size, then re_search
returns -1. When range is positive, re_search
adjusts range so that start + range - 1 is
between zero and size, if necessary; that way it won’t search
outside of string. Similarly, when range is negative,
re_search
adjusts range so that start +
range + 1 is between zero and size, if necessary.
If the fastmap
field of pattern_buffer is zero,
re_search
matches starting at consecutive positions; otherwise,
it uses fastmap
to make the search more efficient.
See Searching with Fastmaps.
If no match is found, re_search
returns -1. If
a match is found, it returns the index where the match began. If an
internal error happens, it returns -2.
Using the functions re_match_2
and re_search_2
, you can
match or search in data that is divided into two strings.
The function:
int re_match_2 (struct re_pattern_buffer *buffer, const char *string1, const int size1, const char *string2, const int size2, const int start, struct re_registers *regs, const int stop)
is similar to re_match
(see GNU Matching) except that you
pass two data strings and sizes, and an index stop beyond
which you don’t want the matcher to try matching. As with
re_match
, if it succeeds, re_match_2
returns how many
characters of string it matched. Regard string1 and
string2 as concatenated when you set the arguments start and
stop and use the contents of regs; re_match_2
never
returns a value larger than size1 + size2.
The function:
int re_search_2 (struct re_pattern_buffer *buffer, const char *string1, const int size1, const char *string2, const int size2, const int start, const int range, struct re_registers *regs, const int stop)
is similarly related to re_search
.
If you’re searching through a long string, you should use a fastmap. Without one, the searcher tries to match at consecutive positions in the string. Generally, most of the characters in the string could not start a match. It takes much longer to try matching at a given position in the string than it does to check in a table whether or not the character at that position could start a match. A fastmap is such a table.
More specifically, a fastmap is an array indexed by the characters in
your character set. Under the ASCII encoding, therefore, a fastmap
has 256 elements. If you want the searcher to use a fastmap with a
given pattern buffer, you must allocate the array and assign the array’s
address to the pattern buffer’s fastmap
field. You either can
compile the fastmap yourself or have re_search
do it for you;
when fastmap
is nonzero, it automatically compiles a fastmap the
first time you search using a particular compiled pattern.
By setting the buffer’s fastmap
field before calling
re_compile_pattern
, you can reuse a buffer data structure across
multiple searches with different patterns, and allocate the fastmap only
once. Nonetheless, the fastmap must be recompiled each time the buffer
has a new pattern compiled into it.
To compile a fastmap yourself, use:
int re_compile_fastmap (struct re_pattern_buffer *pattern_buffer)
pattern_buffer is the address of a pattern buffer. If the
character c could start a match for the pattern,
re_compile_fastmap
makes
pattern_buffer->fastmap[c]
nonzero. It returns
0 if it can compile a fastmap and -2 if there is an
internal error. For example, if ‘|’ is the alternation operator
and pattern_buffer holds the compiled pattern for ‘a|b’, then
re_compile_fastmap
sets fastmap['a']
and
fastmap['b']
(and no others).
re_search
uses a fastmap as it moves along in the string: it
checks the string’s characters until it finds one that’s in the fastmap.
Then it tries matching at that character. If the match fails, it
repeats the process. So, by using a fastmap, re_search
doesn’t
waste time trying to match at positions in the string that couldn’t
start a match.
If you don’t want re_search
to use a fastmap,
store zero in the fastmap
field of the pattern buffer before
calling re_search
.
Once you’ve initialized a pattern buffer’s fastmap
field, you
need never do so again—even if you compile a new pattern in
it—provided the way the field is set still reflects whether or not you
want a fastmap. re_search
will still either do nothing if
fastmap
is null or, if it isn’t, compile a new fastmap for the
new pattern.
If you set the translate
field of a pattern buffer to a translate
table, then the GNU Regex functions to which you’ve passed that
pattern buffer use it to apply a simple transformation
to all the regular expression and string characters at which they look.
A translate table is an array indexed by the characters in your
character set. Under the ASCII encoding, therefore, a translate
table has 256 elements. The array’s elements are also characters in
your character set. When the Regex functions see a character c,
they use translate[c]
in its place, with one exception: the
character after a ‘\’ is not translated. (This ensures that, the
operators, e.g., ‘\B’ and ‘\b’, are always distinguishable.)
For example, a table that maps all lowercase letters to the
corresponding uppercase ones would cause the matcher to ignore
differences in case.7 Such a table would map all characters except lowercase letters
to themselves, and lowercase letters to the corresponding uppercase
ones. Under the ASCII encoding, here’s how you could initialize
such a table (we’ll call it case_fold
):
for (i = 0; i < 256; i++) case_fold[i] = i; for (i = 'a'; i <= 'z'; i++) case_fold[i] = i - ('a' - 'A');
You tell Regex to use a translate table on a given pattern buffer by
assigning that table’s address to the translate
field of that
buffer. If you don’t want Regex to do any translation, put zero into
this field. You’ll get weird results if you change the table’s contents
anytime between compiling the pattern buffer, compiling its fastmap, and
matching or searching with the pattern buffer.
A group in a regular expression can match a (possibly empty) substring of the string that regular expression as a whole matched. The matcher remembers the beginning and end of the substring matched by each group.
To find out what they matched, pass a nonzero regs argument to a GNU matching or searching function (see GNU Matching and GNU Searching), i.e., the address of a structure of this type, as defined in regex.h:
Except for (possibly) the num_regs’th element (see below), the
ith element of the start
and end
arrays records
information about the ith group in the pattern. (They’re declared
as C pointers, but this is only because not all C compilers accept
zero-length arrays; conceptually, it is simplest to think of them as
arrays.)
The start
and end
arrays are allocated in one of two ways.
The simplest and perhaps most useful is to let the matcher (re)allocate
enough space to record information for all the groups in the regular
expression. If re_set_registers
is not called before searching
or matching, then the matcher allocates two arrays each of 1 +
re_nsub elements (re_nsub is another field in the pattern
buffer; see GNU Pattern Buffers). The extra element is set to
-1. Then on subsequent calls with the same pattern buffer and
regs arguments, the matcher reallocates more space if necessary.
The function:
void re_set_registers (struct re_pattern_buffer *buffer, struct re_registers *regs, size_t num_regs, regoff_t *starts, regoff_t *ends)
sets regs to hold num_regs registers, storing
them in starts and ends. Subsequent matches using
buffer and regs will use this memory for recording
register information. starts and ends must be allocated
with malloc, and must each be at least num_regs *
sizeof (regoff_t)
bytes long.
If num_regs is zero, then subsequent matches should allocate their own register data.
Unless this function is called, the first search or match using buffer will allocate its own register data, without freeing the old data.
The following examples illustrate the information recorded in the
re_registers
structure. (In all of them, ‘(’ represents the
open-group and ‘)’ the close-group operator. The first character
in the string string is at index 0.)
regs->start[i]
to the index in string where
the substring matched by the i-th group begins, and
regs->end[i]
to the index just beyond that
substring’s end. The function sets regs->start[0]
and
regs->end[0]
to analogous information about the entire
pattern.
For example, when you match ‘((a)(b))’ against ‘ab’, you get:
regs->start[0]
and 2 in regs->end[0]
regs->start[1]
and 2 in regs->end[1]
regs->start[2]
and 1 in regs->end[2]
regs->start[3]
and 2 in regs->end[3]
For example, when you match the pattern ‘(a)*’ against the string ‘aa’, you get:
regs->start[0]
and 2 in regs->end[0]
regs->start[1]
and 2 in regs->end[1]
regs->start[i]
and
regs->end[i]
to -1.
For example, when you match the pattern ‘(a)*b’ against the string ‘b’, you get:
regs->start[0]
and 1 in regs->end[0]
regs->start[1]
and -1 in regs->end[1]
regs->start[i]
and
regs->end[i]
to the index just beyond that
zero-length string.
For example, when you match the pattern ‘(a*)b’ against the string ‘b’, you get:
regs->start[0]
and 1 in regs->end[0]
regs->start[1]
and 0 in regs->end[1]
regs->start[j]
and
regs->end[j]
the last match (if it matched) of
the j-th group.
For example, when you match the pattern ‘((a*)b)*’ against the string ‘abb’, group 2 last matches the empty string, so you get what it previously matched:
regs->start[0]
and 3 in regs->end[0]
regs->start[1]
and 3 in regs->end[1]
regs->start[2]
and 2 in regs->end[2]
When you match the pattern ‘((a)*b)*’ against the string ‘abb’, group 2 doesn’t participate in the last match, so you get:
regs->start[0]
and 3 in regs->end[0]
regs->start[1]
and 3 in regs->end[1]
regs->start[2]
and 1 in regs->end[2]
regs->start[i]
and
regs->end[i]
to -1, then it also sets
regs->start[j]
and
regs->end[j]
to -1.
For example, when you match the pattern ‘((a)*b)*c’ against the string ‘c’, you get:
regs->start[0]
and 1 in regs->end[0]
regs->start[1]
and -1 in regs->end[1]
regs->start[2]
and -1 in regs->end[2]
To free any allocated fields of a pattern buffer, use the POSIX
function regfree
:
void regfree (regex_t *preg)
preg is the pattern buffer whose allocated fields you want freed;
this works because since the type regex_t
—the type for
POSIX pattern buffers—is equivalent to the type
re_pattern_buffer
.
regfree
also sets preg’s allocated
field to zero.
After a buffer has been freed, it must have a regular expression
compiled in it before passing it to a matching or searching function.
If you’re writing code that has to be Berkeley Unix compatible, you’ll need to use these functions whose interfaces are the same as those in Berkeley Unix.
With Berkeley Unix, you can only search for a given regular
expression; you can’t match one. To search for it, you must first
compile it. Before you compile it, you must indicate the regular
expression syntax you want it compiled according to by setting the
variable re_syntax_options
(declared in regex.h) to some
syntax (see Regular Expression Syntax).
To compile a regular expression use:
char * re_comp (char *regex)
regex is the address of a null-terminated regular expression.
re_comp
uses an internal pattern buffer, so you can use only the
most recently compiled pattern buffer. This means that if you want to
use a given regular expression that you’ve already compiled—but it
isn’t the latest one you’ve compiled—you’ll have to recompile it. If
you call re_comp
with the null string (not the empty
string) as the argument, it doesn’t change the contents of the pattern
buffer.
If re_comp
successfully compiles the regular expression, it
returns zero. If it can’t compile the regular expression, it returns
an error string. re_comp
’s error messages are identical to those
of re_compile_pattern
(see GNU Regular Expression Compiling).
Searching the Berkeley Unix way means searching in a string
starting at its first character and trying successive positions within
it to find a match. Once you’ve compiled a pattern using re_comp
(see BSD Regular Expression Compiling), you can ask Regex
to search for that pattern in a string using:
int re_exec (char *string)
string is the address of the null-terminated string in which you want to search.
re_exec
returns either 1 for success or 0 for failure. It
automatically uses a GNU fastmap (see Searching with Fastmaps).
Gnulib supports many different types of regular expressions; although the underlying features are the same or identical, the syntax used varies. The descriptions given here for the different types are generated automatically.
The character ‘.’ matches any single character except the null character.
indicates that the regular expression should match one or more occurrences of the previous atom or regexp.
indicates that the regular expression should match zero or one occurrence of the previous atom or regexp.
matches a ‘+’
matches a ‘?’.
Bracket expressions are used to match ranges of characters. Bracket expressions where the range is backward, for example ‘[z-a]’, are invalid. Within square brackets, ‘\’ can be used to quote the following character. Character classes are supported; for example ‘[[:digit:]]’ will match a single decimal digit.
GNU extensions are not supported and so ‘\w’, ‘\W’, ‘\<’, ‘\>’, ‘\b’, ‘\B’, ‘\`’, and ‘\'’ match ‘w’, ‘W’, ‘<’, ‘>’, ‘b’, ‘B’, ‘`’, and ‘'’ respectively.
Grouping is performed with parentheses ‘()’. An unmatched ‘)’ matches just itself. A backslash followed by a digit matches that digit.
The alternation operator is ‘|’.
The characters ‘^’ and ‘$’ always represent the beginning and end of a string respectively, except within square brackets. Within brackets, ‘^’ can be used to invert the membership of the character class being specified.
‘*’, ‘+’ and ‘?’ are special at any point in a regular expression except:
The longest possible match is returned; this applies to the regular expression as a whole and (subject to this constraint) to subexpressions within groups.
The character ‘.’ matches any single character.
indicates that the regular expression should match one or more occurrences of the previous atom or regexp.
indicates that the regular expression should match zero or one occurrence of the previous atom or regexp.
matches a ‘+’
matches a ‘?’.
Bracket expressions are used to match ranges of characters. Bracket expressions where the range is backward, for example ‘[z-a]’, are invalid. Within square brackets, ‘\’ is taken literally. Character classes are supported; for example ‘[[:digit:]]’ will match a single decimal digit.
GNU extensions are supported:
Grouping is performed with parentheses ‘()’. An unmatched ‘)’ matches just itself. A backslash followed by a digit acts as a back-reference and matches the same thing as the previous grouped expression indicated by that number. For example ‘\2’ matches the second group expression. The order of group expressions is determined by the position of their opening parenthesis ‘(’.
The alternation operator is ‘|’.
The characters ‘^’ and ‘$’ always represent the beginning and end of a string respectively, except within square brackets. Within brackets, ‘^’ can be used to invert the membership of the character class being specified.
The characters ‘*’, ‘+’ and ‘?’ are special anywhere in a regular expression.
Intervals are specified by ‘{’ and ‘}’. Invalid intervals are treated as literals, for example ‘a{1’ is treated as ‘a\{1’
The longest possible match is returned; this applies to the regular expression as a whole and (subject to this constraint) to subexpressions within groups.
The character ‘.’ matches any single character except the null character.
indicates that the regular expression should match one or more occurrences of the previous atom or regexp.
indicates that the regular expression should match zero or one occurrence of the previous atom or regexp.
match themselves.
Bracket expressions are used to match ranges of characters. Bracket expressions where the range is backward, for example ‘[z-a]’, are invalid. Within square brackets, ‘\’ is taken literally. Character classes are supported; for example ‘[[:digit:]]’ will match a single decimal digit.
GNU extensions are supported:
Grouping is performed with backslashes followed by parentheses ‘\(’, ‘\)’. A backslash followed by a digit acts as a back-reference and matches the same thing as the previous grouped expression indicated by that number. For example ‘\2’ matches the second group expression. The order of group expressions is determined by the position of their opening parenthesis ‘\(’.
The alternation operator is ‘\|’.
The character ‘^’ only represents the beginning of a string when it appears:
The character ‘$’ only represents the end of a string when it appears:
‘\*’, ‘\+’ and ‘\?’ are special at any point in a regular expression except:
Intervals are specified by ‘\{’ and ‘\}’. Invalid intervals such as ‘a\{1z’ are not accepted.
The longest possible match is returned; this applies to the regular expression as a whole and (subject to this constraint) to subexpressions within groups.
The character ‘.’ matches any single character except newline.
indicates that the regular expression should match one or more occurrences of the previous atom or regexp.
indicates that the regular expression should match zero or one occurrence of the previous atom or regexp.
matches a ‘+’
matches a ‘?’.
Bracket expressions are used to match ranges of characters. Bracket expressions where the range is backward, for example ‘[z-a]’, are ignored. Within square brackets, ‘\’ is taken literally. Character classes are not supported, so for example you would need to use ‘[0-9]’ instead of ‘[[:digit:]]’.
GNU extensions are supported:
Grouping is performed with backslashes followed by parentheses ‘\(’, ‘\)’. A backslash followed by a digit acts as a back-reference and matches the same thing as the previous grouped expression indicated by that number. For example ‘\2’ matches the second group expression. The order of group expressions is determined by the position of their opening parenthesis ‘\(’.
The alternation operator is ‘\|’.
The character ‘^’ only represents the beginning of a string when it appears:
The character ‘$’ only represents the end of a string when it appears:
‘*’, ‘+’ and ‘?’ are special at any point in a regular expression except:
The longest possible match is returned; this applies to the regular expression as a whole and (subject to this constraint) to subexpressions within groups.
The character ‘.’ matches any single character.
indicates that the regular expression should match one or more occurrences of the previous atom or regexp.
indicates that the regular expression should match zero or one occurrence of the previous atom or regexp.
matches a ‘+’
matches a ‘?’.
Bracket expressions are used to match ranges of characters. Bracket expressions where the range is backward, for example ‘[z-a]’, are invalid. Within square brackets, ‘\’ can be used to quote the following character. Character classes are supported; for example ‘[[:digit:]]’ will match a single decimal digit.
GNU extensions are supported:
Grouping is performed with parentheses ‘()’. An unmatched ‘)’ matches just itself. A backslash followed by a digit acts as a back-reference and matches the same thing as the previous grouped expression indicated by that number. For example ‘\2’ matches the second group expression. The order of group expressions is determined by the position of their opening parenthesis ‘(’.
The alternation operator is ‘|’.
The characters ‘^’ and ‘$’ always represent the beginning and end of a string respectively, except within square brackets. Within brackets, ‘^’ can be used to invert the membership of the character class being specified.
‘*’, ‘+’ and ‘?’ are special at any point in a regular expression except:
Intervals are specified by ‘{’ and ‘}’. Invalid intervals are treated as literals, for example ‘a{1’ is treated as ‘a\{1’
The longest possible match is returned; this applies to the regular expression as a whole and (subject to this constraint) to subexpressions within groups.
The character ‘.’ matches any single character.
indicates that the regular expression should match one or more occurrences of the previous atom or regexp.
indicates that the regular expression should match zero or one occurrence of the previous atom or regexp.
match themselves.
Bracket expressions are used to match ranges of characters. Bracket expressions where the range is backward, for example ‘[z-a]’, are invalid. Within square brackets, ‘\’ is taken literally. Character classes are supported; for example ‘[[:digit:]]’ will match a single decimal digit.
GNU extensions are supported:
Grouping is performed with backslashes followed by parentheses ‘\(’, ‘\)’. A backslash followed by a digit acts as a back-reference and matches the same thing as the previous grouped expression indicated by that number. For example ‘\2’ matches the second group expression. The order of group expressions is determined by the position of their opening parenthesis ‘\(’.
The alternation operator is ‘\|’.
The character ‘^’ only represents the beginning of a string when it appears:
The character ‘$’ only represents the end of a string when it appears:
‘\*’, ‘\+’ and ‘\?’ are special at any point in a regular expression except:
Intervals are specified by ‘\{’ and ‘\}’. Invalid intervals such as ‘a\{1z’ are not accepted.
The longest possible match is returned; this applies to the regular expression as a whole and (subject to this constraint) to subexpressions within groups.
The character ‘.’ matches any single character except the null character.
indicates that the regular expression should match one or more occurrences of the previous atom or regexp.
indicates that the regular expression should match zero or one occurrence of the previous atom or regexp.
matches a ‘+’
matches a ‘?’.
Bracket expressions are used to match ranges of characters. Bracket expressions where the range is backward, for example ‘[z-a]’, are invalid. Within square brackets, ‘\’ can be used to quote the following character. Character classes are supported; for example ‘[[:digit:]]’ will match a single decimal digit.
GNU extensions are not supported and so ‘\w’, ‘\W’, ‘\<’, ‘\>’, ‘\b’, ‘\B’, ‘\`’, and ‘\'’ match ‘w’, ‘W’, ‘<’, ‘>’, ‘b’, ‘B’, ‘`’, and ‘'’ respectively.
Grouping is performed with parentheses ‘()’. An unmatched ‘)’ matches just itself. A backslash followed by a digit acts as a back-reference and matches the same thing as the previous grouped expression indicated by that number. For example ‘\2’ matches the second group expression. The order of group expressions is determined by the position of their opening parenthesis ‘(’.
The alternation operator is ‘|’.
The characters ‘^’ and ‘$’ always represent the beginning and end of a string respectively, except within square brackets. Within brackets, ‘^’ can be used to invert the membership of the character class being specified.
‘*’, ‘+’ and ‘?’ are special at any point in a regular expression except the following places, where they are not allowed:
Intervals are specified by ‘{’ and ‘}’. Invalid intervals are treated as literals, for example ‘a{1’ is treated as ‘a\{1’
The longest possible match is returned; this applies to the regular expression as a whole and (subject to this constraint) to subexpressions within groups.
The character ‘.’ matches any single character except the null character.
indicates that the regular expression should match one or more occurrences of the previous atom or regexp.
indicates that the regular expression should match zero or one occurrence of the previous atom or regexp.
matches a ‘+’
matches a ‘?’.
Bracket expressions are used to match ranges of characters. Bracket expressions where the range is backward, for example ‘[z-a]’, are invalid. Within square brackets, ‘\’ is taken literally. Character classes are supported; for example ‘[[:digit:]]’ will match a single decimal digit.
GNU extensions are supported:
Grouping is performed with parentheses ‘()’. An unmatched ‘)’ matches just itself. A backslash followed by a digit acts as a back-reference and matches the same thing as the previous grouped expression indicated by that number. For example ‘\2’ matches the second group expression. The order of group expressions is determined by the position of their opening parenthesis ‘(’.
The alternation operator is ‘|’.
The characters ‘^’ and ‘$’ always represent the beginning and end of a string respectively, except within square brackets. Within brackets, ‘^’ can be used to invert the membership of the character class being specified.
‘*’, ‘+’ and ‘?’ are special at any point in a regular expression except the following places, where they are not allowed:
Intervals are specified by ‘{’ and ‘}’. Invalid intervals such as ‘a{1z’ are not accepted.
The longest possible match is returned; this applies to the regular expression as a whole and (subject to this constraint) to subexpressions within groups.
The character ‘.’ matches any single character except the null character.
Bracket expressions are used to match ranges of characters. Bracket expressions where the range is backward, for example ‘[z-a]’, are invalid. Within square brackets, ‘\’ is taken literally. Character classes are supported; for example ‘[[:digit:]]’ will match a single decimal digit.
GNU extensions are supported:
Grouping is performed with backslashes followed by parentheses ‘\(’, ‘\)’. A backslash followed by a digit acts as a back-reference and matches the same thing as the previous grouped expression indicated by that number. For example ‘\2’ matches the second group expression. The order of group expressions is determined by the position of their opening parenthesis ‘\(’.
The character ‘^’ only represents the beginning of a string when it appears:
The character ‘$’ only represents the end of a string when it appears:
Intervals are specified by ‘\{’ and ‘\}’. Invalid intervals such as ‘a\{1z’ are not accepted.
The longest possible match is returned; this applies to the regular expression as a whole and (subject to this constraint) to subexpressions within groups.
Gnulib has a couple of modules that don’t provide code, but rather extend the GNU Build System. That is, they are convenience facilities for use with GNU Automake (in particular).
The following macros check for the presence or location of certain C, C++, or Fortran library archive files.
The macros AC_CHECK_LIB
, AC_SEARCH_LIBS
from GNU Autoconf check
for the presence of certain C, C++, or Fortran library archive files.
The libraries are looked up in the default linker path—a system dependent
list of directories, that usually contains the /usr/lib directory—and
those directories given by -L
options in the LDFLAGS
variable.
The following macros, defined in the Gnulib module havelib
, search for
the location of certain C, C++, or Fortran library archive files and make the
found location available to the compilation process and to further Autoconf
tests.
AC_LIB_LINKFLAGS(name, [dependencies])
¶Searches for lib<name>
and the libraries corresponding to
explicit and implicit dependencies. Sets and AC_SUBSTs the
LIB<NAME>
and LTLIB<NAME>
variables (with
<NAME>
in upper case) and augments the CPPFLAGS
variable
by -I
options.
This macro should be used when lib<name>
is expected to be found.
AC_LIB_HAVE_LINKFLAGS(name, [dependencies], [includes], [testcode], [missing-message])
¶Searches for lib<name>
and the libraries corresponding to
explicit and implicit dependencies, together with the specified include files
and the ability to compile and link the specified testcode. The
missing-message defaults to no
and may contain additional hints
for the user. If found, it sets and AC_SUBSTs HAVE_LIB<NAME>=yes
and the LIB<NAME>
and LTLIB<NAME>
variables (with
<NAME>
in upper case) and augments the CPPFLAGS
variable
by -I
options, and #defines HAVE_LIB<NAME>
to 1.
Otherwise, it sets and AC_SUBSTs HAVE_LIB<NAME>=no
and
LIB<NAME>
and LTLIB<NAME>
to empty.
These macros assume that when a library is installed in
some_directory/lib
, its include files are installed in
some_directory/include
.
The complexities that AC_LIB_LINKFLAGS
and AC_LIB_HAVE_LINKFLAGS
deal with are the following:
CPPFLAGS
for
the include file search path, LDFLAGS
for the library search path).
The macro provides a ‘--with-lib<name>’ option. The user of the
‘configure’ script can use this option to indicate the location of the
library and its include files. If not provided, the --prefix
directory
is searched as well.
LD_LIBRARY_PATH
, the macro adds the appropriate run time search path
options to the LIB<NAME>
variable. This works on most systems.
It can also be inhibited: The user of ‘configure’ can use the
--disable-rpath
option to force an installation that doesn’t contain
hardcoded library search paths but instead may require the use of an
environment variable like LD_LIBRARY_PATH
.
The macros also set a variable LTLIB<NAME>
, that should be used
when linking with libtool. Both LTLIB<NAME>
and
LIB<NAME>
contain essentially the same option, but where
LIB<NAME>
contains platform dependent flags like
‘-Wl,-rpath’, LTLIB<NAME>
contains platform independent
flags like ‘-R’.
If you, by mistake, use LIB<NAME>
instead of
LTLIB<NAME>
when linking with libtool, you will observe that the
binaries created in the build dir will prefer the shared libraries in the
installation directories over the shared libraries in the build dir; this can
lead to all sorts of build failures, test failures, or crashes!
If you, on the other hand, by mistake, use LTLIB<NAME>
instead of
LIB<NAME>
when linking without libtool, you will observe
build failures, because the ‘-R’ options contained in
LTLIB<NAME>
are not valid options to compilers such as GCC.
AC_LIB_LINKFLAGS
CPPFLAGS
vs. LDFLAGS
AC_LIB_LINKFLAGS
¶Suppose you want to use libz
, the compression library.
AC_CONFIG_AUX_DIR([build-aux]) AC_LIB_LINKFLAGS([z])
Note that since the AC_LIB_LINKFLAGS
invocation modifies the CPPFLAGS,
it should precede all tests that check for header files, declarations,
structures or types.
havelib
module.
(gnulib-tool
will usually do this for you automatically.)
Makefile.in
you add @LIBZ@
to the link command line of
your program. Or, if you are using Automake, you add $(LIBZ)
to the
LDADD
variable that corresponds to your program.
The dependencies list is a space separated list of library names that
libname
is known to depend upon. Example: If libfooy
depends on libfoox
, and libfooz
depends on libfoox
and
libfooy
, you can write:
AC_LIB_LINKFLAGS([foox]) AC_LIB_LINKFLAGS([fooy], [foox]) AC_LIB_LINKFLAGS([fooz], [foox fooy])
Explicit dependencies are necessary if you cannot assume that a .la
file, created by libtool, is installed. If you can assume that
libfooy.la
is installed by libtool (and has not been omitted by the
package distributor!), you can omit the explicit dependency and just write
AC_LIB_LINKFLAGS([fooy])
This way, you don’t need to know in advance which libraries the needed library depends upon.
CPPFLAGS
vs. LDFLAGS
¶The macros determine the directories that should be added to the compiler
preprocessor’s search path and to the linker’s search path. For the
compiler preprocessor, -I
options with the necessary directories are
added to the CPPFLAGS
variable, for use by the whole package. For
the linker, appropriate options are added to the LIB<NAME>
and
LTLIB<NAME>
variables, for use during linking by those programs
and libraries that need the dependency on lib<name>
. You need
to use the value of LIB<NAME>
or LTLIB<NAME>
in the
Makefiles. LTLIB<NAME>
is for use with libtool, whereas
LIB<NAME>
is for when libtool is not involved in linking.
The macros do not check whether the include files and the library found match. If you want to verify this at configure time, one technique is to have a version number in the include files and a version number in the library, like this:
#define LIBNAME_VERSION 10203 extern int libname_version; /* initialized to LIBNAME_VERSION */
and use a test like
AC_TRY_RUN([int main () { return libname_version != LIBNAME_VERSION; }])
A bi-arch system is one where
On several types of such systems, for historical reasons, the 32-bit libraries are installed in prefix/lib, whereas the 64-bit libraries are installed in
On such systems, in 64-bit mode, configure
will search for the
libraries in prefix/lib64 or prefix/lib/64,
respectively, not in prefix/lib. A user can adhere to these
system-wide conventions by using the ‘--libdir’ option when installing
packages. When a user has already installed packages in 64-bit mode using
the GNU default ‘--libdir=prefix/lib’, he can make this directory
adhere to the system-wide convention by placing a symbolic link:
ln -s lib prefix/lib64
ln -s . prefix/lib/64
The lib-symbol-versions
module can be used to add shared
library versioning support. Currently, only GNU LD and the Solaris
linker supports this.
Version scripts provides information that can be used by GNU/Linux
distribution packaging tools. For example, Debian has a tool
dpkg-shlibdeps
that can determine the minimal required version
of each dependency (by looking at the symbol list) and stuff the
information into the Debian specific packaging files.
For more information and other uses of version scripts, see Ulrich Drepper’s paper https://www.akkadia.org/drepper/dsohowto.pdf
You use the module by importing it to your library, and then add the
following lines to the Makefile.am
that builds the library:
if HAVE_LD_VERSION_SCRIPT libfoo_la_LDFLAGS += -Wl,--version-script=$(srcdir)/libfoo.map endif
The version script file format is documented in the GNU LD manual, but a small example would be:
LIBFOO_1.0 { global: libfoo_init; libfoo_doit; libfoo_done; local: *; };
If you target platforms that do not support linker scripts (i.e., all
platforms that doesn’t use GNU LD) you may want to consider a more
portable but less powerful alternative: libtool
-export-symbols
. It will hide internal symbols from your
library, but will not add ELF versioning symbols. Your usage would
then be something like:
if HAVE_LD_VERSION_SCRIPT libfoo_la_LDFLAGS += -Wl,--version-script=$(srcdir)/libfoo.map else libfoo_la_LDFLAGS += -export-symbols $(srcdir)/libfoo.sym endif
See the Libtool manual for the file syntax, but a small example would be:
libfoo_init libfoo_doit libfoo_done
To avoid the need for a *.sym
file if your symbols are easily
expressed using a regular expression, you may use
-export-symbols-regex
:
if HAVE_LD_VERSION_SCRIPT libfoo_la_LDFLAGS += -Wl,--version-script=$(srcdir)/libfoo.map else libfoo_la_LDFLAGS += -export-symbols-regex '^libfoo_.*' endif
For more discussions about symbol visibility, rather than shared
library versioning, see the visibility
module
(see Controlling the Exported Symbols of Shared Libraries).
The configmake
module builds a C include file named
configmake.h containing the usual installation directory
values; for example, those specified by --prefix
or
--libdir
to configure. Each variable is given a #define
with an all-uppercase macro name, such as PREFIX
and
LIBDIR
. (Automake cannot create this file directly because the
user might override directory values at make
time.)
Specifically, the module retrieves values of the variables through
configure
followed by make
, not directly through
configure
, so that a user who sets some of these variables
consistently on the make
command line gets correct results.
One advantage of this approach, compared to the classical approach of
adding -DLIBDIR=\"$(libdir)\"
etc. to AM_CPPFLAGS
, is
that it protects against the use of undefined variables. That is, if,
say, $(libdir)
is not set in the Makefile, LIBDIR
is not
defined by this module, and code using LIBDIR
gives a
compilation error.
Another advantage is that make
output is shorter.
For the complete list of variables which are #define
d this way,
see the file gnulib/modules/configmake, or inspect your
resulting gnulib Makefile.
The warnings
module allows to regularly build a package with more
GCC warnings than the default warnings emitted by GCC. It is often used
indirectly through the manywarnings
module
(see manywarnings).
It provides the following functionality:
CFLAGS
variable at configuration time.
CFLAGS
does not work in general, because it may
break autoconfiguration.)
configure
with an option such as
--enable-gcc-warnings.
To use this module, you need the following:
gl_WARN_ADD([-Wall], [WARN_CFLAGS]) gl_WARN_ADD([-Wpointer-arith], [WARN_CFLAGS])
WARN_CFLAGS
, use it in the
definition of AM_CFLAGS
, like this:
AM_CFLAGS = $(WARN_CFLAGS)
Note that the AM_CFLAGS
is used in combination with CFLAGS
and before CFLAGS
in build rules emitted by Automake. This allows
the user to provide CFLAGS
that override the WARN_CFLAGS
.
‘gl_WARN_ADD([-Werror])’ is intended for developers, and should be avoided in contexts where it would affect ordinary installation builds. The warnings emitted by GCC depend, to some extent, on the contents of the system header files, on the size and signedness of built-in types, etc. Use of ‘-Werror’ would cause frustration to all users on platforms that the maintainer has not tested before the release. It is better if ‘-Werror’ is off by default, and is enabled only by developers. For example, ‘-Werror’ could affect ‘make distcheck’ or ‘configure --enable-gcc-warnings’ as mentioned above.
The manywarnings
module enables many GCC warnings for your
package. Here is an example use:
AC_ARG_ENABLE([gcc-warnings], [AS_HELP_STRING([[--enable-gcc-warnings[=TYPE]]], [control generation of GCC warnings. The TYPE 'no' disables warnings; 'yes' (default) generates cheap warnings; 'expensive' in addition generates expensive warnings.])]) AS_IF([test "$enable_gcc_warnings" != no], [ # Set up the list of unwanted warning options. nw= if test "$enable_gcc_warnings" != expensive; then nw="$nw -fanalyzer" fi nw="$nw -Wbad-function-cast" # Casting a function's result is not more # dangerous than casting any other value. nw="$nw -Winline" # It's OK to not inline. nw="$nw -Wsign-compare" # Too many false alarms. nw="$nw -Wstrict-overflow" # It's OK to optimize strictly. nw="$nw -Wsystem-headers" # Don't warn in system headers. # Setup the list of meaningful warning options for the C compiler. # The list comes from manywarnings.m4. Warning options that are not # generally meaningful have already been filtered out (cf. # build-aux/gcc-warning.spec). gl_MANYWARN_ALL_GCC([possible_warning_options]) # Compute the list of warning options that are desired. gl_MANYWARN_COMPLEMENT([desired_warning_options], [$possible_warning_options], [$nw]) # Compute the list of remaining undesired warning options. # Namely those, that were not in manywarnings.m4 because they were # already listed in build-aux/gcc-warning.spec; this includes those # that are implied by -Wall. gl_MANYWARN_COMPLEMENT([remaining_undesired_warning_options], [$nw], [$possible_warning_options]) # Add the desired warning options to WARN_CFLAGS. for w in $desired_warning_options; do gl_WARN_ADD([$w]) done # Add the opposites of the remaining undesired warning options to # WARN_CFLAGS. for w in `echo "$remaining_undesired_warning_options" | sed -e 's/-W/-Wno-/g'`; do gl_WARN_ADD([$w]) done ])
This module sets up many GCC warning options.
When you use it for the first time, it is common practice to do it as follows:
-Wstrict-overflow
or
-Wunsafe-loop-optimizations
).
configure
default to -O2 optimization.
If you also commonly build with -O0 or other optimization options,
you can compile again with those options.
Using more optimizations catches more bugs, because the compiler does
a better static analysis of the program when optimizing more.
Also, some warning options that diagnose suboptimal code generation,
such as -Winline
, are not effective when not optimizing.
On the other hand, if it’s frequent to build the package with warnings but
without optimizations, for debugging purposes, then you don’t want to see
undesired warnings in these phases of development either.
nw
value, that is, with all
possible warnings enabled.
$ grep warning: make-output.log \ | sed -e 's/^\(.*\) \[\(-W.*\)\]$/\2 \1/' | sort -k1
Many GCC warning options usually don’t point to mistakes in the code; these warnings enforce a certain programming style. It is a project management decision whether you want your code to follow any of these styles. Note that some of these programming styles are conflicting. You cannot have them all; you have to choose among them.
When a warning option pinpoints real bugs occasionally, but it also
whines about a few code locations which are fine, we recommend to leave
the warning option enabled.
Whether you then live with the remaining few warnings, or choose to
disable them one-by-one through
#pragma GCC diagnostic ignored "option"
(see Diagnostic Pragmas in Using the GNU Compiler Collection,
https://gcc.gnu.org/onlinedocs/gcc/Diagnostic-Pragmas.html),
is again a project management decision.
When a new major version of GCC is released, the Gnulib maintainers add
the newly available warning options into the gl_MANYWARN_ALL_GCC
macro.
You will then enjoy the benefits of the new warnings, simply by updating
to the newest Gnulib.
If some of the new warnings are undesired, you can add them to the
‘nw’ variable, as described above.
Comments on particular warning flags:
The manywarnings
module by default uses GCC’s
-fanalyzer option, as this issues some useful warnings.
(It can also help GCC generate better code.)
However, -fanalyzer
can greatly slow down compilation,
and in programs with large modules it can be so slow as to be unusable,
so it is common for configure
to disable it unless
configure
is given an option like
--enable-gcc-warnings=expensive.
Although the manywarnings
module does not enable GCC’s
-fstrict-aliasing option, it is enabled by default if you
compile with -O2
or higher optimization, and can help GCC
generate better warnings.
The -fanalyzer
option generates many false alarms about
malloc
leaks, which manywarnings
suppresses by also
using -Wno-analyzer-malloc-leak.
The manywarnings
module by default uses GCC’s
-fstrict-flex-arrays option if available, so that GCC can
warn about nonportable usage of flexible array members.
In a few cases this can help GCC generate better code,
so it is not strictly a warning option.
GCC and Clang generate too many false alarms with -Wsign-compare,
and we don’t recommend that warning. You can disable it by using
gl_WARN_ADD([-Wno-sign-compare])
as illustrated above.
Programs using Gnulib generally don’t enable
that warning when compiling Gnulib code. If you happen to find a real
bug with that warning we’d like to know it.
For projects written in C or similar languages, running the self-tests
under Valgrind can reveal hard to find memory issues. Gnulib supports
two ways to make use of Valgrind: one that enables use of Valgrind at
configure time, when configure
found it to be present; and one
at the discretion of the developer.
The valgrind-tests
module searches for Valgrind at configure time
and declares the LOG_VALGRIND
automake variable for use with
automake’s LOG_COMPILER
.
After importing the valgrind-tests
module to your project, you
use it by adding the following to the Makefile.am
that runs the
self-tests:
LOG_COMPILER = $(LOG_VALGRIND)
This will run all self-checks under valgrind.
Replace LOG_COMPILER
with TESTS_ENVIRONMENT
if you are
using the old serial test harness. The parallel test harness has been
the default in automake since version 1.11.3, but if you are using an
older automake, or put ‘serial-tests’ in
‘AM_INIT_AUTOMAKE’/‘AUTOMAKE_OPTIONS’ you would still be using
the serial test harness.
If you desire a project-wide decision that valgrind is not enabled by
default, but still allow users to enable it with
--enable-valgrind-tests
you may put the following in configure.ac
before gl_INIT.
gl_VALGRIND_TESTS_DEFAULT_NO
The VALGRIND
variable holds the name of the valgrind binary and
some options passed to valgrind. You may provide additional options
that are passed to valgrind using the ‘VALGRINDFLAGS’ variable, for
example:
./configure VALGRINDFLAGS="--suppressions=~/local.supp"
Alternatively during build phase:
make check VALGRINDFLAGS="--suppressions=~/local.supp"
This is useful if you have a valgrind suppression files that are needed to avoid triggering errors for known errors, typically in system libraries.
The VALGRIND
variable include options that are useful when
valgrind is run non-interactively through the test harness. The default
parameters are -q
to silence the output,
--error-exitcode=1
to cause valgrind errors to be treated as
fatal errors, and --leak-check=full
to check for memory leaks.
These options can be controlled through the DEFAULT_VALGRINDFLAGS
variable. For example, when configuring the package:
./configure DEFAULT_VALGRINDFLAGS="--quiet"
Alternatively, during the build phase:
make check DEFAULT_VALGRINDFLAGS="--quiet"
That would have the effect of removing --error-exitcode=1
and
--leak-check=full
from the default options, thus causing any
valgrind errors to be silently ignored, instead of causing fatal test
failures.
As a developer you may use the variables in configure.ac
before
calling gl_INIT
, like this if your program has deeply-nested call
chains:
gl_EARLY ... VALGRINDFLAGS="$VALGRINDFLAGS --num-callers=42" ... gl_INIT
Note that any user-supplied VALGRINDFLAGS
value is preserved,
which is usually what you want.
Finally, as a developer you may want to provide additional per-directory
options to valgrind and the AM_VALGRINDFLAGS
variable can be used
for this. For example:
AM_VALGRINDFLAGS = --suppressions=$(srcdir)/local-valgrind.supp LOG_COMPILER = $(LOG_VALGRIND)
In this approach, you define a Makefile.am
variable ‘VALGRIND’
(or, more abstractly, ‘CHECKER’), that is usually set to empty.
When you have configured and built the package and you decide that you want
to run the tests with valgrind, you do so by modifying the definition of
‘VALGRIND’ in the Makefile.
It is not desirable to apply valgrind to shell scripts or other non-binaries, because
There are two ways to avoid this:
TEST_EXTENSIONS = .pl .sh LOG_COMPILER = $(LOG_VALGRIND)
Then valgrind will only be used for the non-.sh and non-.pl tests.
For old automake (before 1.11.3), you will need AUTOMAKE_OPTIONS =
parallel-tests
to enable the parallel test harness.
build-aux/run-test
script from Gnulib.
Add these lines to your Makefile.am
:
LOG_COMPILER += $(SHELL) $(top_srcdir)/build-aux/run-test '$(LOG_VALGRIND)'
Replace LOG_COMPILER
with TESTS_ENVIRONMENT
if you use the
old serial test harness.
However, with this measure in place, binaries invoked through scripts will
not be invoked under valgrind. This can be solved by defining environment
variables in the TESTS_ENVIRONMENT
variable that are then used by the
shell scripts. For example, add the following:
TESTS_ENVIRONMENT = VALGRIND='$(LOG_VALGRIND)'
And then modify the shell scripts to invoke the binary prefixed with
$VALGRIND
.
Gnulib provides the ‘vcs-to-changelog’ module to generate an output similar to the GNU ChangeLog format from metadata of source control software such as git. Here’s an example of using ‘vcs-to-changelog’:
build-aux/vcs-to-changelog.py <from_ref> <to_ref>
where <from_ref>
and <to_ref>
refer to the range of commits to
generate the output.
VCS To ChangeLog currently recognises changes in C source code and can traverse commits in git. Additional source frontends and source control backends may be added to the module. ‘vcs-to-changelog’ takes the following optional arguments:
-d
: Run the parser debugger, used for debugging
‘vcs-to-changelog’
-q filename
: Load filename as the quirks file for the
project.
The quirks file is a python module that must minimally implement a
get_project_quirks
function that returns an object of type
ProjectQuirks
or its subclass. The subclass may override the following
members of ProjectQuirks
:
repo
: Specify the project repo source control. The default value
is git
.
IGNORE_LIST
: A list of files to ignore in the changesets, either
because they are not needed (such as the ChangeLog) or because they are
not parseable. For example, the GNU C Library has a header file that is only
assembly code, which breaks the C parser.
MACRO_QUIRKS
: A list of dictionary entries with indexes as
orig
and sub
where orig
is a Python regular expression
pattern to match and sub
is the substitution. These substitutions are
used to work around C/C++ macros that are known to break parsing of C programs.
C_MACROS
: This is a list of C preprocessor macro definitions that
are extensively used and are known to break parsing due to some characteristic,
mainly the lack of a semicolon at the end.
Gnulib contains also a small number of files that are not part of
modules. They are meant to be imported into packages by means of
‘gnulib-tool --copy-file’, not ‘gnulib-tool --import’. For
example, the commands to import the files config.guess
and
config.sub
are
for file in config.guess config.sub; do $GNULIB_TOOL --copy-file build-aux/$file \ && chmod a+x build-aux/$file \ || exit $? done
Packages that don’t use Gnulib can get hold of these files through direct download from Gnulib’s git repository. The commands to do this look as follows:
for file in config.guess config.sub; do echo "$0: getting $file..." wget -q --timeout=5 -O build-aux/$file.tmp "https://git.savannah.gnu.org/gitweb/?p=gnulib.git;a=blob_plain;f=build-aux/${file};hb=HEAD" \ && mv build-aux/$file.tmp build-aux/$file \ && chmod a+x build-aux/$file retval=$? rm -f build-aux/$file.tmp test $retval -eq 0 || exit $retval done
build-aux/config.guess
build-aux/config.sub
These files are helper scripts, invoked by the ‘configure’ script.
config.guess
recognizes the platform on which the script is
running, and produces a triplet of the form
cpu-type-vendor-operating_system
.
config.sub
receives a possibly abbreviated triplet and produces a
canonical triplet for a platform. For more information, see
https://www.gnu.org/prep/standards/html_node/Configuration.html.
It is important that you always include the newest versions of these two files in your tarball, because people who work on emerging platforms otherwise have a hard time building your package.
These programs can be used in Makefiles. Some of them are also described in https://www.gnu.org/software/automake/manual/html_node/Auxiliary-Programs.html.
build-aux/ar-lib
build-aux/compile
These two scripts are necessary for supporting portability to native
Windows with the MSVC compiler. compile
is a wrapper script that
invokes the compiler and provides a command-line interface compatible
with Unix compilers. Similarly, ar-lib
is a wrapper script that
provides a command-line interface compatible with Unix ar
.
build-aux/depcomp
This is a helper script, used by Makefile rules generated by GNU Automake. It generates Makefile dependencies while compiling a file.
build-aux/install-sh
This is a helper script, used by Makefile rules generated by GNU
Automake. It installs files during the make install
phase. In
the Makefile, don’t use this file directly; always use
$(INSTALL_PROGRAM)
or $(INSTALL_DATA)
instead.
build-aux/mdate-sh
This script determines the modification time of a file and pretty-prints it. The typical use is to add a “Last modified” line to the documentation.
build-aux/mkinstalldirs
This is a helper script, used by Makefile rules generated by GNU
Automake. It creates directories during the make install
phase.
It is roughly equivalent to ‘mkdir -p’ (except that the latter is
not portable). In the Makefile, don’t use this file directly; always
use $(MKDIR_P)
instead.
build-aux/mktempd
This script creates a temporary directory. It is roughly equivalent to ‘mktemp -d’ (except that the latter is not portable).
build-aux/move-if-change
This script moves a freshly generated file to a destination file, with a special optimization for the case that both files are identical. In this case the freshly generated file is deleted, and the time stamp of the destination file is not changed. This is useful when updating a file that rarely actually changes and which many Makefile targets depend upon.
These programs can help when developing in a Git checkout. The maintainer of the package copies these programs into the version control of the package, so that co-developers can use these tools right away.
top/gitsub.sh
This program manages the subdirectories of a Git checkout that come from other packages, including Gnulib.
top/bootstrap
top/autopull.sh
top/autogen.sh
top/bootstrap-funclib.sh
This is a set of three programs and a function library, that manage the source directory of a package, preparing for the state where ‘./configure’ can be used.
autopull.sh
is a program for fetching dependencies that may
require network accesses. It manages the Git submodules, including
Gnulib – assuming that Gnulib is a Git submodule. It also can fetch
the PO files for internationalized packages.
autogen.sh
is a program that is meant to be run after
autopull.sh
. It generates all autogeneratable files that are
omitted from version control. Usually this means that it invokes
gnulib-tool
and automake
, that generate files from other
files.
bootstrap
is a wrapper around both:
./bootstrap --pull
is equivalent to ./autopull.sh
,
./bootstrap --gen
is equivalent to ./autogen.sh
.
Plain ./bootstrap
is equivalent to ./autopull.sh
immediately followed by ./autogen.sh
; however, because plain
./bootstrap
mixes version control management and
generation of files in non-obvious ways, it has a number of usability
issues for the advanced developer.
bootstrap-funclib.sh
is a function library for these three
programs. It is not meant to be used directly.
All three programs make use of a configuration file, called
bootstrap.conf
.
build-aux/bootstrap
This acts like top/bootstrap
, except it does not
need the companion files autogen.sh
,
autopull.sh
, and bootstrap-funclib.sh
so it avoids some clutter in your project’s top level directory.
With this approach, you update via ./bootstrap --pull
and
./bootstrap --gen
instead of via ./autopull.sh
and
./autogen.sh
. Otherwise this approach acts similarly, and
uses the same bootstrap.conf
file.
build-aux/bootstrap.conf
This is the template configuration file. After copying it into the top-level directory of your package, you need to customize it.
build-aux/po/Makefile.in.in
build-aux/po/remove-potcdate.sin
These are auxiliary files used by bootstrap
. You don’t have to
copy them yourself; bootstrap
will do that.
These are auxiliary files for building documentation.
build-aux/texinfo.tex
This file is needed for the conversion of Texinfo-format documentation to PDF, PostScript, or DVI formats. It implements the GNU Texinfo commands on top of plain TeX.
build-aux/x-to-1.in
This file, once processed, gives a program x-to-1
, that produces
a manual page for a program, by combining a skeleton with the program’s
--help
output.
build-aux/declared.sh
This program extracts the declared global symbols of a C header file. It is useful when you want to control the set of symbols exported by a library. See Controlling the Exported Symbols of Shared Libraries.
build-aux/run-test
This file is a test driver that supports running a test under
valgrind
.
build-aux/test-driver.diff
This is a patch, against Automake’s test driver, that supports running a test suite on Android.
Gnulib also contain a few scripts that are useful for the release management of a package. They can be used directly off the Gnulib checkout; they don’t need to copied first.
build-aux/gnupload
This program is a user-friendly way to upload a release tarball to one of
the GNU servers (ftp.gnu.org
or alpha.gnu.org
). It
implements the interface described in
https://www.gnu.org/prep/maintain/html_node/Automated-FTP-Uploads.html.
build-aux/ncftpput-ftp
This is a helper program that mimics the ncftpput
program used by
gnupload
. If you want to use gnupload
but don’t have
ncftp
installed, copy this file into your $PATH, renaming it to
ncftpput
.
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Ristenpart T, Yilek S. When good randomness goes bad: virtual machine vulnerabilities and hedging deployed cryptography. NDSS 2010.
Ristenpart T, Yilek S. When good randomness goes bad: virtual machine vulnerabilities and hedging deployed cryptography. NDSS 2010.
Sometimes
you don’t have to explicitly quote special characters to make
them ordinary. For instance, most characters lose any special meaning
inside a list (see List Operators ([
… ]
and [^
… ]
)). In addition, if the syntax bits
RE_CONTEXT_INVALID_OPS
and RE_CONTEXT_INDEP_OPS
aren’t set, then (for historical reasons) the matcher considers special
characters ordinary if they are in contexts where the operations they
represent make no sense; for example, then the match-zero-or-more
operator (represented by ‘*’) matches itself in the regular
expression ‘*foo’ because there is no preceding expression on which
it can operate. It is poor practice, however, to depend on this
behavior; if you want a special character to be ordinary outside a list,
it’s better to always quote it, regardless.
Regex therefore doesn’t consider the ‘^’ to be the first character in the list. If you put a ‘^’ character first in (what you think is) a matching list, you’ll turn it into a nonmatching list.
You can’t use a character class for the starting or ending point of a range, since a character class is not a single character.
Regular expressions are also referred to as “patterns,” hence the name “pattern buffer.”
A table that maps all uppercase letters to the corresponding lowercase ones would work just as well for this purpose.