NAME
sigemptyset,
sigfillset,
sigaddset,
sigdelset,
sigismember —
manipulate signal
sets
LIBRARY
Standard C Library (libc, -lc)
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. 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.
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
kill(2),
sigaction(2),
sigsuspend(2),
signal(7)
STANDARDS
These functions conform to
IEEE Std 1003.1-1990
(“POSIX.1”).