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\"     from: @(#)sigsetmask.2   8.1 (Berkeley) 6/2/93
\"      $NetBSD: sigsetmask.3,v 1.19 2013/05/06 13:29:12 wiz Exp $
\"
Dd August 10, 2002
Dt SIGSETMASK 3
Os
Sh NAME
Nm sigsetmask
Nd set current signal mask
Sh LIBRARY
Lb libc
Sh SYNOPSIS
In signal.h
Ft int
Fn sigsetmask "int mask"
Fn sigmask signum
Sh DESCRIPTION
Bf -symbolic
This interface is made obsolete 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 RETURN VALUES
The previous set of masked signals is returned.
Sh EXAMPLES
The following example using
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 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.