POSIX_SPAWNATTR_GETFLAGS (man3p)
posix_spawnattr_getflags, posix_spawnattr_setflags — get and set the spawn-flags attribute of a spawn attributes object (ADVANCED REALTIME)
posix_spawnattr_getflags, posix_spawnattr_setflags — get and set the spawn-flags attribute of a spawn attributes object (ADVANCED REALTIME)
wcsnrtombs, wcsrtombs — convert a wide-character string to a character string (restartable)
ungetwc — push wide-character code back into the input stream
accept — accept a new connection on a socket
setpgrp — set the process group ID
scandir — scan a directory
lgamma, lgammaf, lgammal, signgam — log gamma function
sqrt, sqrtf, sqrtl — square root function
posix_trace_get_filter, posix_trace_set_filter — retrieve and set the filter of an initialized trace stream (TRACING)
pthread_rwlock_tryrdlock — lock a read-write lock object for reading