4.3BSD - /usr/man/cat2/sigblock.0

SIGBLOCK(2)                                                        SIGBLOCK(2)


NAME
       sigblock - block signals

SYNOPSIS
       #include <signal.h>

       sigblock(mask);
       int mask;

       mask = sigmask(signum)

DESCRIPTION
       Sigblock causes the signals specified in mask to be added 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,  SIGSTOP,  or  SIGCONT;   this
       restriction is silently imposed by the system.

RETURN VALUE
       The previous set of masked signals is returned.

SEE ALSO
       kill(2), sigvec(2), sigsetmask(2)


4.2 Berkeley Distribution        May 14, 1986                      SIGBLOCK(2)