SIGSETOPS(3)		   Linux Programmer's Manual		  SIGSETOPS(3)

NAME
       sigemptyset, sigfillset, sigaddset, sigdelset, sigismember - POSIX sig-
       nal set operations.
SYNOPSIS
       #include <signal.h>

       int sigemptyset(sigset_t *set);

       int sigfillset(sigset_t *set);

       int sigaddset(sigset_t *set, int signum);

       int sigdelset(sigset_t *set, int signum);

       int sigismember(const sigset_t *set, int signum);

   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

       sigemptyset(), sigfillset(), sigaddset(), sigdelset(), sigismember():
	   _POSIX_C_SOURCE >= 1 || _XOPEN_SOURCE || _POSIX_SOURCE

DESCRIPTION
       These functions allow the manipulation of POSIX signal sets.

       sigemptyset() initializes the signal set given by set  to  empty,  with
       all signals excluded from the set.

       sigfillset() initializes set to full, including all signals.

       sigaddset()  and  sigdelset() add and delete respectively signal signum
       from set.

       sigismember() tests whether signum is a member of set.

       Objects of type sigset_t must  be  initialized  by  a  call  to	either
       sigemptyset()  or  sigfillset()	before	being  passed to the functions
       sigaddset(), sigdelset() and  sigismember()  or	the  additional  glibc
       functions  described  below  (sigisemptyset(),  sigandset(),  and  sig-
       orset()).  The results are undefined if this is not done.

RETURN VALUE
       sigemptyset(), sigfillset(), sigaddset(), and sigdelset() return  0  on
       success and -1 on error.

       sigismember()  returns  1  if signum is a member of set, 0 if signum is
       not a member, and -1 on error.

ERRORS
       EINVAL sig is not a valid signal.

CONFORMING TO
       POSIX.1-2001.

NOTES
   Glibc Notes
       If the _GNU_SOURCE feature  test  macro	is  defined,  then  <signal.h>
       exposes three other functions for manipulating signal sets.

       int sigisemptyset(sigset_t *set);
	      returns 1 if set contains no signals, and 0 otherwise.

       int sigorset(sigset_t *dest, sigset_t *left, sigset_t *right);
	      places the union of the sets left and right in dest.

       int sigandset(sigset_t *dest, sigset_t *left, sigset_t *right);
	      places the intersection of the sets left and right in dest.

       sigorset() and sigandset() return 0 on success, and -1 on failure.

       These  functions  are  nonstandard (a few other systems provide similar
       functions) and their use should be avoided in portable applications.

SEE ALSO
       sigaction(2), sigpending(2), sigprocmask(2), sigsuspend(2)

COLOPHON
       This page is part of release 3.44 of the Linux  man-pages  project.   A
       description  of	the project, and information about reporting bugs, can
       be found at http://www.kernel.org/doc/man-pages/.



Linux				  2008-09-01			  SIGSETOPS(3)