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SIGSETMASK(2) System Calls Manual SIGSETMASK(2)

NAME

sigsetmask, sigblock
manipulate current signal mask

LIBRARY

Standard C Library (libc, -lc)

SYNOPSIS

#include <signal.h>

int
sigsetmask(int mask);

int
sigblock(int mask);

int
sigmask(int signum);

DESCRIPTION

This interface is made obsolete by:
sigprocmask(2).

The sigsetmask() function sets the current signal mask to the specified mask. Signals are blocked from delivery if the corresponding bit in mask is a 1. The sigblock() function adds the signals in the specified mask to the current signal mask, rather than overwriting it as sigsetmask() does. 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 sigblock() and sigsetmask() functions return the previous set of masked signals.

SEE ALSO

kill(2), sigaction(2), sigprocmask(2), sigsuspend(2), sigvec(2), sigsetops(3)

HISTORY

The sigsetmask() and sigblock() functions first appeared in 4.2BSD and have been deprecated.
June 2, 1993 Linux 4.19.0-6-amd64