VSSCANF (man3p)
vsscanf — format input of a stdarg argument list
vsscanf — format input of a stdarg argument list
sigwait — wait for queued signals
semop — XSI semaphore operations
casinl — complex arc sine functions
posix_trace_attr_getname — retrieve and set information about a trace stream (TRACING)
optarg, opterr, optind, optopt — options parsing variables
iconv_close — codeset conversion deallocation function
getmsg, getpmsg — receive next message from a STREAMS file (STREAMS)
rewind — reset the file position indicator in a stream
posix_spawnattr_getpgroup, posix_spawnattr_setpgroup — get and set the spawn-pgroup attribute of a spawn attributes object (ADVANCED REALTIME)