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Command: sigsetmask | Section: 3 | Source: NetBSD | File: sigsetmask.3
SIGSETMASK(3) FreeBSD Library Functions Manual SIGSETMASK(3)
NAME
sigsetmask - set current signal mask
LIBRARY
Standard C Library (libc, -lc)
SYNOPSIS
#include <signal.h>
int
sigsetmask(int mask);
sigmask(signum);
DESCRIPTION
This interface is made obsolete by: sigprocmask(2).
sigsetmask() sets the current signal mask. Signals are blocked from
delivery if the corresponding bit in mask is a 1; the macro sigmask() is
provided to construct the mask for a given signum.
The system quietly disallows SIGKILL or SIGSTOP to be blocked.
RETURN VALUES
The previous set of masked signals is returned.
EXAMPLES
The following example using sigsetmask():
int omask;
omask = sigblock(sigmask(SIGINT) | sigmask(SIGHUP));
...
sigsetmask(omask & ~(sigmask(SIGINT) | sigmask(SIGHUP)));
Could be converted literally to:
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);
Another, clearer, alternative is:
sigset_t set;
sigemptyset(&set);
sigaddset(&set, SIGINT);
sigaddset(&set, SIGHUP);
sigprocmask(SIG_BLOCK, &set, NULL);
...
sigprocmask(SIG_UNBLOCK, &set, NULL);
To completely clear the signal mask using sigsetmask() one can do:
(void) sigsetmask(0);
Which can be expressed via sigprocmask(2) as:
sigset_t eset;
sigemptyset(&eset);
(void) sigprocmask(SIG_SETMASK, &eset, NULL);
SEE ALSO
kill(2), sigaction(2), sigprocmask(2), sigsuspend(2), sigblock(3),
sigsetops(3), sigvec(3)
HISTORY
The sigsetmask() function call appeared in 4.2BSD and has been
deprecated.
FreeBSD 14.1-RELEASE-p8 August 10, 2002 FreeBSD 14.1-RELEASE-p8