sigemptyset, sigfillset, sigaddset, sigdelset, sigismember - POSIX signal set operations
#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
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.
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 of
the error.
signum is not a valid signal.
For an explanation of the terms used in this section, see attributes(7).
| Interface | Attribute | Value |
| sigemptyset(),
sigfillset(), sigaddset(), sigdelset(), sigismember(), sigisemptyset(), sigorset(), sigandset() |
Thread safety | MT-Safe |
POSIX.1-2001, POSIX.1-2008.
When creating a filled signal set, the glibc sigfillset() function does not include the two real-time signals used internally by the NPTL threading implementation. See nptl(7) for details.
If the _GNU_SOURCE feature test macro is defined,
then <signal.h> exposes three other functions for
manipulating signal sets:
int sigisemptyset(const sigset_t *set);
int sigorset(sigset_t *dest, const sigset_t *left,
const sigset_t *right);
int sigandset(sigset_t *dest, const sigset_t *left,
const sigset_t *right);sigisemptyset() returns 1 if set contains
no signals, and 0 otherwise.
sigorset() places the union of the sets
left and right in dest.
sigandset() places the intersection of the sets
left and right in dest. Both functions 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.
sigaction(2), sigpending(2), sigprocmask(2), sigsuspend(2)
This page is part of release 5.10 of the Linux man-pages
project. A description of the project, information about reporting bugs,
and the latest version of this page, can be found at
https://www.kernel.org/doc/man-pages/.