.TH SIGPROCMASK 2
.SH NAME
sigprocmask \- manipulate the signal mask
.SH SYNOPSIS
.ft B
#include <signal.h>

int sigprocmask(int \fIhow\fP, const sigset_t *\fIset\fP, sigset_t *\fIoset\fP)
.ft P
.SH DESCRIPTION
.B Sigprocmask()
examines or manipulates the signal mask.  This mask is the set of signals
that are currently blocked.  The
.I how
argument determines the action that must be performed.  In all cases the
signal set referenced by
.IR oset ,
if not
.BR NULL ,
will be used to receive the old signal mask.  The
.I set
argument, if not
.BR NULL ,
will be used to set or modify the current signal mask.
.PP
.I How
can be one of:
.PP
.TP 15
.B SIG_BLOCK
Add the signals referenced by
.I set
to the mask.
.TP
.B SIG_UNBLOCK
Remove the signals referenced by
.I set
from the mask.
.TP
.B SIG_SETMASK
Set the signal mask to the set referenced by
.IR set .
.PP
The value of
.I how
is ignored if
.I set
is
.BR NULL .
.SH "SEE ALSO"
.BR sigaction (2),
.BR sigpending (2),
.BR sigsuspend (2),
.BR sigset (3).
.SH DIAGNOSTICS
Returns
.B 0
on success and
.B \-1
on error.  The error code is
.B EFAULT
for a bad
.I set
or
.I oset
address, or
.B EINVAL
for a bad
.I how
argument.
.SH AUTHOR
Kees J. Bot (kjb@cs.vu.nl)

.\"
.\" $PchId: sigprocmask.2,v 1.2 1996/04/11 06:02:09 philip Exp $