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 sigorset()).  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 porta-
       ble applications.

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

COLOPHON
       This page is part of release 3.25 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)