.\"	@(#)sigwait.2 1.0 (2.11BSD) 1999/9/10
.\"
.TH SIGACTION 2 "September 10, 1999"
.UC 7
.SH NAME
\fBsigwait\fP \- wait for a signal
.SH SYNOPSIS
.B #include <signal.h>
.sp
int
\fBsigwait\fP(set, sig)
.br
.I sigset_t *set;
.br
.I int *sig;
.SH DESCRIPTION
.B Sigwait
checks for a pending signal in 
.IR set ,
clears it from the set of pending signals and returns the signal number
in the location referenced by
.IR sig .
If more than one of the signals contained in
.I set
is pending then
.B sigwait
selects only one and acts upon it.
If no signal contained in
.I set
is pending, then
.B sigwait
waits for a signal to arrive.
All of the signals contained in
.I set
should be blocked or unpredictable results may occur.
.SH RETURN VALUES
The
.B sigwait
function returns 0 if successful and the signal number is stored in the
location referenced by
.IR sig .
.SH ERRORS
The
.B sigwait
function may return one of the following errors:
.TP 20
EINVAL
The
.I set
argument contains an invalid or unsupported signal number.
.TP 20
EFAULT
.I Sig
points to memory that is not a valid part of the process address space.
.SH SEE ALSO
sigprocmask(2)
.SH STANDARDS
The
.B sigwait
function call
conforms to
IEEE Std1003.1-1998 (``POSIX'').