sigaddset, sigdelset, sigemptyset, sigfillset, sigismember -- Modify the Signals in a Set of Signals



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 OpenEdition. 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);

SEE ALSO

Copyright (c) 1998 SAS Institute Inc. Cary, NC, USA. All rights reserved.