NAME
sigemptyset,
sigfillset, sigaddset,
sigandset, sigdelset,
sigisemptyset, sigismember,
sigorset —
manipulate signal sets
LIBRARY
library “libc”
SYNOPSIS
#include
<signal.h>
int
sigemptyset(sigset_t
*set);
int
sigfillset(sigset_t
*set);
int
sigaddset(sigset_t
*set, int
signo);
int
sigandset(sigset_t
*set, const sigset_t
*left, const sigset_t
*right);
int
sigdelset(sigset_t
*set, int
signo);
int
sigisemptyset(const
sigset_t *set);
int
sigismember(const
sigset_t *set, int
signo);
int
sigorset(sigset_t
*set, const sigset_t
*left, const sigset_t
*right);
DESCRIPTION
These functions manipulate signal sets stored in a sigset_t. Eithersigemptyset()
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
sigandset()
function sets the specified set to the logical AND of
all signals from the left and
right signal sets.
The
sigdelset()
function deletes the specified signal signo from the
signal set.
The
sigisemptyset()
function returns whether the specified set is empty or
not.
The
sigismember()
function returns whether a specified signal signo is
contained in the signal set.
The
sigorset()
function sets the specified set to the logical OR of
all signals from the left and
right signal sets.
RETURN VALUES
The sigisemptyset() function returns 1 if
the set is empty, 0 otherwise.
The sigismember() function returns 1 if
the signal is a member of the set, 0 otherwise.
The other functions return 0 upon success. A -1 return value indicates an error occurred and the global variable errno is set to indicate the reason.
ERRORS
These functions could fail if one of the following occurs:
- [
EINVAL] - signo has an invalid value.
SEE ALSO
kill(2), sigaction(2), sigpending(2), sigprocmask(2), sigsuspend(2)
STANDARDS
The sigandset(),
sigisemptyset(), and
sigorset() functions are FreeBSD extensions,
compatible with functions of the same name provided by both musl libc and
GNU libc.
The rest of these functions are defined by IEEE Std 1003.1-1988 (“POSIX.1”).