NAME

     sigemptyset, sigfillset, sigaddset, sigdelset, sigismember -
     POSIX signal set operations.



SYNOPSIS

     #include <signal.h>


     int sigemptyset(sigset_t *set));

     int sigfillset(sigset_t *set));

     int sigaddset(sigset_t *set, int signum));

     int sigdelset(sigset_t *set, int signum));

     int sigismember(const sigset_t *set, int signum));



DESCRIPTION

     The sigsetops(3) functions allow the manipulation  of  POSIX
     signal sets.

     sigemptyset initializes the  signal  set  given  by  set  to
     empty, with all signals excluded from the set.

     sigfillset initializes set to full, including all signals.

     sigaddset and sigdelset add and delete  respectively  signal
     signum from set.

     sigismember tests whether signum is a member of set.



RETURN VALUES

     sigemptyset, sigfullset, sigaddset and sigdelset return 0 on
     success and -1 on error.

     sigismember returns 1 if signum is a member  of  set,  0  if
     signum is not a member, and -1 on error.



ERRORS

     EINVAL
          sig is not a valid signal.



CONFORMING TO

     POSIX



SEE ALSO

     sigaction(2), sigpending(2), sigprocmask(2), sigsuspend(2)