sigaddset - Man Page

add a signal to a signal set

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.

Synopsis

#include <signal.h>

int sigaddset(sigset_t *set, int signo);

Description

The sigaddset() function adds the individual signal specified by the signo to the signal set pointed to by set.

Applications shall 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, sigaddset() shall return 0; otherwise, it shall return -1 and set errno to indicate the error.

Errors

The sigaddset() function may fail if:

EINVAL

The value of the signo argument is an invalid or 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(), sigdelset(), sigemptyset(), sigfillset(), sigismember(), sigpending(), sigsuspend()

The Base Definitions volume of POSIX.1-2017, <signal.h>

Referenced By

pthread_sigmask(3p), sigaction(3p), sigdelset(3p), sigemptyset(3p), sigfillset(3p), sigismember(3p), signal.h(0p), sigpending(3p), sigsuspend(3p).

2017 IEEE/The Open Group POSIX Programmer's Manual