.\"
.\" $Id: sigpause.2,v 1.1 1997/02/27 07:32:16 gdr Exp $
.\"
.TH SIGPAUSE 2 "19 January 1997" GNO "System Calls"
.SH NAME
.BR sigpause
\- suspend process until a signal arrives
.SH SYNOPSIS
#include <signal.h>
.sp 1
int
\fBsigpause\fR(long int \fImask\fR);
.SH DESCRIPTION
.BR sigpause
suspends execution of the calling process until a signal arrives.  The
.IR mask
parameter is assigned to the set of blocked signals (see
.BR sigsetmask (2)),
and then the process is paused.  When a signal arrives, the regular
signal handler (if any) is executed, and then the original signal mask
is restored before returning to the caller.  Usually 
.IR mask
is zero to pause until any signal arrives.
.LP
.BR sigpause
is normally used in situations where one must protect a critical section.
A typical use begins with sigblock to block a signal (and enable mutual
exclusion); variables modified on the occurance of that signal are then
manipulated, code is executed, etc.  To end the critical section and
wait for more work, sigpause is called.
.SH RETURN VALUE
.BR sigpause 
always returns an error (-1) and sets
.BR errno
to EINTR.
.SH SEE ALSO
.BR signal (2),
.BR sigblock (2),
.BR sigsetmask (2)