osx man page for sigwait

SIGWAIT(2)						      BSD System Calls Manual							SIGWAIT(2)

NAME
     sigwait -- select a set of signals

SYNOPSIS
     #include <signal.h>

     int
     sigwait(const sigset_t *restrict set, int *restrict sig);

DESCRIPTION
     The sigwait() function selects a set of signals, specified by set.  If none of the selected signals are pending, sigwait() waits until one or
     more of the selected signals has been generated.  Then sigwait() atomically clears one of the selected signals from the set of pending sig-
     nals for the process and sets the location pointed to by sig to the signal number that was cleared.

     The signals specified by set should be blocked, but not ignored, at the time of the call to sigwait().

     Processes which call sigwait() on ignored signals will wait indefinitely.	Ignored signals are dropped immediately by the system, before
     delivery to a waiting process.

RETURN VALUES
     If successful, sigwait() returns 0 and sets the location pointed to by sig to the cleared signal number.  Otherwise, an error number is
     returned.

ERRORS
     sigwait() will fail if:

     [EINVAL]		set specifies one or more invalid signal numbers.

SEE ALSO
     pthread_sigmask(2), sigaction(2), sigpending(2), sigsuspend(2), pause(3)

STANDARDS
     sigwait() conforms to ISO/IEC 9945-1:1996 (``POSIX.1'')

BSD
								  April 27, 2000							       BSD