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¶

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.