POSIX header C standard header Not in POSIX
aio.h
 stdalign.h (since C11)
arpa/inet.h stdatomic.h (since C11)
assert.h assert.h stdnoreturn.h (since C11)
complex.h complex.h (since C99) threads.h (since C11)
cpio.h uchar.h (since C11)
ctype.h ctype.h
dirent.h
dlfcn.h
errno.h errno.h
fcntl.h
fenv.h fenv.h (since C99)
float.h float.h
fmtmsg.h
fnmatch.h
ftw.h
glob.h
grp.h
iconv.h
inttypes.h inttypes.h (since C99)
iso646.h iso646.h (since C95)
langinfo.h
libgen.h
limits.h limits.h
locale.h locale.h
math.h math.h
monetary.h
mqueue.h
ndbm.h
net/if.h
netdb.h
netinet/in.h
netinet/tcp.h
nl_types.h
poll.h
pthread.h
pwd.h
regex.h
sched.h
search.h
semaphore.h
setjmp.h setjmp.h
signal.h signal.h
spawn.h
stdarg.h stdarg.h
stdbool.h stdbool.h (since C99)
stddef.h stddef.h
stdint.h stdint.h (since C99)
stdio.h stdio.h
stdlib.h stdlib.h
string.h string.h
strings.h
stropts.h
sys/ipc.h
sys/mman.h
sys/msg.h
sys/resource.h
sys/select.h
sys/sem.h
sys/shm.h
sys/socket.h
sys/stat.h
sys/statvfs.h
sys/time.h
sys/times.h
sys/types.h
sys/uio.h
sys/un.h
sys/utsname.h
sys/wait.h
syslog.h
tar.h
termios.h
tgmath.h tgmath.h (since C99)
time.h time.h
trace.h
ulimit.h
unistd.h
utime.h
utmpx.h
wchar.h wchar.h (since C95)
wctype.h wctype.h (since C95)
wordexp.h