.\" Copyright (c) 1983, 1991 The Regents of the University of California.
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.\"	$OpenBSD: sigsetmask.3,v 1.10 2001/01/18 18:51:44 millert Exp $
.\"
.Dd March 10, 1991
.Dt SIGSETMASK 3
.Os
.Sh NAME
.Nm sigsetmask
.Nd set current signal mask
.Sh SYNOPSIS
.Fd #include <signal.h>
.Ft int
.Fn sigsetmask "int mask"
.Fn sigmask "int signum"
.Sh DESCRIPTION
.Bf -symbolic
This interface is made obsoleted by:
.Ef
.Xr sigprocmask 2 .
.Pp
.Fn sigsetmask
sets the current signal mask.
Signals are blocked from delivery if the
corresponding bit in
.Fa mask
is a 1; the macro
.Fn sigmask
is provided to construct the mask for a given
.Fa signum .
.Pp
The system
quietly disallows
.Dv SIGKILL
or
.Dv SIGSTOP
to be blocked.
.Sh EXAMPLES
The following example utilizing
.Fn sigsetmask :
.Bd -literal -offset indent
int omask;

omask = sigblock(sigmask(SIGINT) | sigmask(SIGHUP));

\&...

sigsetmask(omask & ~(sigmask(SIGINT) | sigmask(SIGHUP)));
.Ed
.Pp
Could be converted literally to:
.Bd -literal -offset indent
sigset_t set, oset;

sigemptyset(&set);
sigaddset(&set, SIGINT);
sigaddset(&set, SIGHUP);
sigprocmask(SIG_BLOCK, &set, &oset);

\&...

sigdelset(&oset, SIGINT);
sigdelset(&oset, SIGHUP);
sigprocmask(SIG_SETMASK, &oset, NULL);
.Ed
.Pp
Another, clearer, alternative is:
.Bd -literal -offset indent
sigset_t set;

sigemptyset(&set);
sigaddset(&set, SIGINT);
sigaddset(&set, SIGHUP);
sigprocmask(SIG_BLOCK, &set, NULL);

\&...

sigprocmask(SIG_UNBLOCK, &set, NULL);
.Ed
.Pp
To completely clear the signal mask using
.Fn sigsetmask
one can do:
.Bd -literal -offset indent
(void) sigsetmask(0);
.Ed
.Pp
Which can be expressed via
.Xr sigprocmask 2
as:
.Bd -literal -offset indent
sigset_t eset;

sigemptyset(&eset);
(void) sigprocmask(SIG_SETMASK, &eset, NULL);
.Ed
.Sh RETURN VALUES
The previous set of masked signals is returned.
.Sh SEE ALSO
.Xr kill 2 ,
.Xr sigaction 2 ,
.Xr sigprocmask 2 ,
.Xr sigsuspend 2 ,
.Xr sigblock 3 ,
.Xr sigsetops 3 ,
.Xr sigvec 3
.Sh HISTORY
The
.Fn sigsetmask
function call appeared in
.Bx 4.2
and has been deprecated.