sigemptyset —
sigfillset,
sigaddset,
sigdelset,
sigismember
manipulate signal sets
SYNOPSIS
#include <signal.h> intsigemptyset(sigset_t *set);
intsigfillset(sigset_t *set);
intsigaddset(sigset_t *set, int signo);
intsigdelset(sigset_t *set, int signo);
intsigismember(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.
sigemptyset();
and
sigfillset();
are provided as macros, but actual functions are available
if their names are undefined (with #undef
name)).
The
sigemptyset();
function initializes a signal set to be empty.
sigfillset();
initializes a signal set to contain all signals.
sigaddset();
adds the specified signal
signo
to the signal set.
sigdelset();
deletes the specified signal
signo
from the signal set.
sigismember();
returns whether a specified signal
signo
is contained in the signal set.
RETURN VALUES
The
sigismember();
function returns 1
if the signal is a member of the set and 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 may fail if one of the following occurs:
[EINVAL]
The specified signal
signo
is not a valid signal number.