NAME
sigemptyset, sigfillset, sigaddset, sigdelset, sigismember - POSIX
signal set operations.
SYNOPSIS
#include <signal.h>
I int sigemptyset(sigset_t * set );
I int sigfillset(sigset_t * set );
I int sigaddset(sigset_t * set , int signum );
I int sigdelset(sigset_t * set , int signum );
I int sigismember(const sigset_t * set , int signum );
DESCRIPTION
The
sigsetops(3)
functions allow the manipulation of POSIX signal sets.
R sigemptyset ()
initializes the signal set given by
set
to empty, with all signals excluded from the set.
R sigfillset ()
initializes
set
to full, including all signals.
R sigaddset ()
and
R sigdelset ()
add and delete respectively signal
signum
from
R set .
R sigismember ()
tests whether
signum
is a member of
R set .
RETURN VALUE
R sigemptyset (),
R sigfillset (),
R sigaddset (),
and
R sigdelset ()
return 0 on success and -1 on error.
R sigismember ()
returns 1 if
signum
is a member of
R set ,
0 if
signum
is not a member, and -1 on error.
ERRORS
EINVAL
sig
is not a valid signal.
CONFORMING TO
POSIX.1-2001.
NOTES
Glibc Notes
If the
_GNU_SOURCE
feature test macro is defined, then
<signal.h>
exposes three other functions for manipulating signal
sets.
I int sigisemptyset(sigset_t * set );
returns 1 if
set
contains no signals, and 0 otherwise.
I int sigorset(sigset_t * dest , sigset_t * left \
", sigset_t *" right );
places the union of the sets
left
and
right
in
R dest .
I int sigandset(sigset_t * dest , sigset_t * left \
", sigset_t *" right );
places the intersection of the sets
left
and
right
in
R dest .
R sigorset ()
and
R sigandset ()
return 0 on success, and -1 on failure.
These functions are non-standard (a few other systems provide similar
functions) and their use should be avoided in portable applications.
SEE ALSO
