SIGBLOCK(3)

NAME
sigblock - block signals

LIBRARY
libc

SYNOPSIS
#include <signal.h>
int
sigblock(int mask);
int
sigmask(signum);

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

Sigblock() adds the signals specified in mask to the set of signals currently being blocked from delivery. Signals are blocked if the corresponding bit in mask is a 1; the macro sigmask() is provided to construct the mask for a given signum.

It is not possible to block SIGKILL or SIGSTOP; this restriction is silently imposed by the system.

RETURN VALUES
The previous set of masked signals is returned.

SEE ALSO
kill(2), sigaction(2), sigprocmask(2), sigsetmask(3), sigsetops(3)

HISTORY
The sigblock() function call appeared in 4.2BSD and has been deprecated.