sigblock(2) [mojave man page]

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

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