sigsetops(3C)

NAME

     sigsetops, sigemptyset,  sigfillset,  sigaddset,  sigdelset,
     sigismember - manipulate sets of signals

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 sigset_t data types, representing
     the set of signals supported by the implementation.

     The sigemptyset() function initializes the set pointed to by
     set to exclude all signals defined by the system.

     The sigfillset() function initializes the set pointed to  by
     set to include all signals defined by the system.

     The sigaddset() function adds the individual  signal  speci-
     fied by the value of signo to the set pointed to by set.

     The  sigdelset()  function  deletes  the  individual  signal
     specified  by  the value of signo from the set pointed to by
     set.

     The sigismember() function checks whether the signal  speci-
     fied by the value of signo is a member of the set pointed to
     by set.

     Any object of type sigset_t must be initialized by  applying
     either  sigemptyset()  or  sigfillset()  before applying any
     other operation.

RETURN VALUES

     Upon  successful  completion,  the  sigismember()   function
     returns  1 if the specified signal is a member of the speci-
     fied set, or 0 if it is not.

     Upon successful completion, the other  functions  return  0.
     Otherwise  -1  is  returned and errno is set to indicate the
     error.

ERRORS

     The sigaddset(), sigdelset(),  and  sigismember()  functions
     will fail if:

     EINVAL
           The value of the signo argument is not a valid  signal
           number.

     The sigfillset() function will fail if:

     EFAULT
           The set argument specifies an invalid address.

ATTRIBUTES

     See attributes(5) for descriptions of the  following  attri-
     butes:

     ____________________________________________________________
    |       ATTRIBUTE TYPE        |       ATTRIBUTE VALUE       |
    |_____________________________|_____________________________|
    | MT-Level                    | MT-Safe                     |
    |_____________________________|_____________________________|

SEE ALSO

     sigaction(2), sigpending(2), sigprocmask(2),  sigsuspend(2),
     attributes(5), signal(3HEAD)