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

NAME

       sigemptyset, sigfillset, sigaddset, sigdelset, sigismember - POSIX signal 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.  On error, these functions set errno to
       indicate the cause.

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 3.53 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								    2013-04-19							      SIGSETOPS(3)