NetBSD/lib/libc/compat-43/sigsetmask.3

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.\"     from: @(#)sigsetmask.2	8.1 (Berkeley) 6/2/93
.\"	$NetBSD: sigsetmask.3,v 1.18 2003/08/07 16:42:40 agc 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.