SIGISMEMBER
Section: POSIX Programmer's Manual (3P)
Updated: 2017
Page Index
PROLOG
This manual page is part of the POSIX Programmer's Manual.
The Linux implementation of this interface may differ (consult
the corresponding Linux manual page for details of Linux behavior),
or the interface may not be implemented on Linux.
NAME
sigismember
--- test for a signal in a signal set
SYNOPSIS
#include <signal.h>
int sigismember(const sigset_t *set, int signo);
DESCRIPTION
The
sigismember()
function shall test whether the signal specified by
signo
is a member of the set pointed to by
set.
Applications should call either
sigemptyset()
or
sigfillset()
at least once for each object of type
sigset_t
prior to any other use of that object. If such an object is not
initialized in this way, but is nonetheless supplied as an argument to
any of
pthread_sigmask(),
sigaction(),
sigaddset(),
sigdelset(),
sigismember(),
sigpending(),
sigprocmask(),
sigsuspend(),
sigtimedwait(),
sigwait(),
or
sigwaitinfo(),
the results are undefined.
RETURN VALUE
Upon successful completion,
sigismember()
shall return 1 if the specified signal is a member of the specified set,
or 0 if it is not. Otherwise, it shall return -1 and set
errno
to indicate the error.
ERRORS
The
sigismember()
function may fail if:
- EINVAL
-
The
signo
argument is not a valid signal number, or is an unsupported signal
number.
The following sections are informative.
EXAMPLES
None.
APPLICATION USAGE
None.
RATIONALE
None.
FUTURE DIRECTIONS
None.
SEE ALSO
Section 2.4,
Signal Concepts,
pthread_sigmask(),
sigaction(),
sigaddset(),
sigdelset(),
sigfillset(),
sigemptyset(),
sigpending(),
sigsuspend()
The Base Definitions volume of POSIX.1-2017,
<signal.h>
COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1-2017, Standard for Information Technology
-- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 7, 2018 Edition,
Copyright (C) 2018 by the Institute of
Electrical and Electronics Engineers, Inc and The Open Group.
In the event of any discrepancy between this version and the original IEEE and
The Open Group Standard, the original IEEE and The Open Group Standard
is the referee document. The original Standard can be obtained online at
http://www.opengroup.org/unix/online.html .
Any typographical or formatting errors that appear
in this page are most likely
to have been introduced during the conversion of the source files to
man page format. To report such errors, see
https://www.kernel.org/doc/man-pages/reporting_bugs.html .