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.