osx man page for sigblock

SIGBLOCK(2)						      BSD System Calls Manual						       SIGBLOCK(2)

NAME
     sigblock -- block signals

LIBRARY
     Standard C Library (libc, -lc)

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 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