sigaddset, sigdelset, sigemptyset, sigfillset, sigismember

sigaddset, sigdelset, sigemptyset, sigfillset, sigismember

Modify the Signals in a Set of Signals

Portability: POSIX.1 conforming

SYNOPSIS
DESCRIPTION
RETURN VALUE
EXAMPLE
SEE ALSO

SYNOPSIS

#include <lcsignal.h>

int sigaddset(sigset_t *set, int signum);
int sigdelset(sigset_t *set, int signum);
int sigemptyset(sigset_t *set);
int sigfillset(sigset_t *set);
int sigismember(const sigset_t *set, int signum);

For the POSIX implementation, include the header file <signal.h> after defining an appropriate feature test macro.

DESCRIPTION

sigaddset , sigdelset , sigemptyset , sigfillset , and sigismember enable you to modify the sigset_t object addressed by set . The sigset_t function is defined in <signal.h> and <lcsignal.h> as a type representing a collection of signal numbers. Signal sets are passed as arguments to other signal handling functions, such as sigprocmask , sigpending , and oesigsetup .

The functions that modify signals in a set of signals include

sigaddset adds the signal signum to the set.

sigdelset deletes the signal signum from the set.

sigemptyset initializes a set to contain no signals.

sigfillset initializes a set to contain all signals.

sigismember tests to see if signum is a member of the set.

RETURN VALUE

sigismember returns 1 if signum is a member of the set, or 0 if it is not in the set. All other functions return 0 if successful. All functions return -1 if an error occurs (such as an invalid signal number).

EXAMPLE

The following example uses these functions to set up signal sets for oesigsetup . The call to oesigsetup defines SIGALRM and SIGFPE as signals managed by SAS/C, and all others as signals managed by USS. See the sigpending example for an example using sigismember .

#include <lcsignal.h>

sigset_t sascset, oeset;
sigemptyset(&sascset);
sigaddset(&sascset, SIGFPE);
/* SAS/C will manage SIGALRM and SIGFPE. */
sigaddset(&sascser, SIGALRM); 
sigfillset(&oeset);
sigdelset(&oeset, SIGFPE);
/* OpenEdition manages everything else   */
/* (whenever possible).                  */
sigdelset(&oeset, SIGALRM); 
  
oesigsetup(&oeset, &sascset);

`sigaddset`	adds the signal `signum` to the set.
`sigdelset`	deletes the signal `signum` from the set.
`sigemptyset`	initializes a set to contain no signals.
`sigfillset`	initializes a set to contain all signals.
`sigismember`	tests to see if `signum` is a member of the set.