sigblock(2) [bsd man page]

SIGBLOCK(2)							System Calls Manual						       SIGBLOCK(2)

NAME

       sigblock - block signals

SYNOPSIS

       #include <signal.h>

       omask = sigblock(mask);
       long omask, mask;

       mask = sigmask(signum)
       long mask;
       int 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)

SIGBLOCK(3)						   BSD Library Functions Manual 					       SIGBLOCK(3)

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.

EXAMPLES

     The following example using sigblock():

	   int omask;

	   omask = sigblock(sigmask(SIGINT) | sigmask(SIGHUP));

     Becomes:

	   sigset_t set, oset;

	   sigemptyset(&set);
	   sigaddset(&set, SIGINT);
	   sigaddset(&set, SIGHUP);
	   sigprocmask(SIG_BLOCK, &set, &oset);

     Another use of sigblock() is to get the current set of masked signals without changing what is actually blocked.  Instead of:

	   int set;

	   set = sigblock(0);

     Use the following:

	   sigset_t set;

	   sigprocmask(SIG_BLOCK, NULL, &set);

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.

BSD
								  August 10, 2002							       BSD