CONFSTR (man3p)
confstr — get configurable variables
confstr — get configurable variables
fgetws — get a wide-character string from a stream
mknod, mknodat — make directory, special file, or regular file
signal — signal management
catgets — read a program message
shmget — get an XSI shared memory segment
catan, catanf, catanl — complex arc tangent functions
access, faccessat — determine accessibility of a file descriptor
posix_trace_eventid_equal, posix_trace_eventid_get_name, posix_trace_trid_eventid_open — manipulate the trace event type identifier (TRACING)
tanl — tangent function