NAME
sigemptyset,
sigfillset, sigaddset,
sigdelset, sigismember
— 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
sigdelset(sigset_t
*set, int
signo);
int
sigismember(sigset_t
*set, int
signo);
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
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.
sigemptyset()
and sigfillset() are provided as macros, but 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, a 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
STANDARDS
These functions conform to IEEE Std 1003.1-1990 (“POSIX.1”).