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 cur-
     rently being blocked from delivery.  Signals are blocked if the corre-
     sponding 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(2), sigsetops(3)

HISTORY

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

BSD                              June 2, 1993                              BSD