NAME

sigaddset, sigdelset, sigemptyset, sigfillset, sigismember — manipulate signal sets

LIBRARY

Standard C Library (libc, -lc)

SYNOPSIS

#include <signal.h>

int
sigaddset(sigset_t *set, int signo);

int
sigdelset(sigset_t *set, int signo);

int
sigemptyset(sigset_t *set);

int
sigfillset(sigset_t *set);

int
sigismember(const sigset_t *set, int signo);

DESCRIPTION

These functions manipulate signal sets, stored in a sigset_t. Either sigemptyset() or sigfillset() must be called for every object of type sigset_t before any other use of the object.

The sigemptyset() function initializes a signal set to be empty.

The sigfillset() function initializes a signal set to contain all signals.

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

The sigdelset() function deletes the specified signal signo from the signal set.

The sigismember() function returns whether a specified signal signo is contained in the signal set.

These functions are provided as macros in the include file <signal.h>. Actual functions are available if their names are undefined (with #undef name).

RETURN VALUES

The sigismember() function returns 1 if the signal is a member of the set, 0 otherwise. The other functions return 0.

ERRORS

Currently, no errors are detected.

SEE ALSO

kill(2), sigaction(2), sigsuspend(2)

STANDARDS

These functions are defined by IEEE Std 1003.1-1988 (“POSIX.1”).