SIGSETOPS(3)              OpenBSD Programmer's Manual             SIGSETOPS(3)

NAME
     sigemptyset, sigfillset, sigaddset, sigdelset, sigismember - manipulate
     signal sets



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 signal sets stored in a sigset_t. Either
     sigemptyset() or sigfillset() must be called for every object of type
     sigset_t before any other use of the object.  sigemptyset() and
     sigfillset() are provided as macros, but actual functions are available
     if their names are undefined (with #undef name).

     The sigemptyset() function initializes a signal set to be empty.

     sigfillset() initializes a signal set to contain all signals.

     sigaddset() adds the specified signal signo to the signal set.

     sigdelset() deletes the specified signal signo from the signal set.

     sigismember() returns whether a specified signal signo is contained in
     the signal set.

RETURN VALUES
     The sigismember() function returns 1 if the signal is a member of the
     set, a 0 otherwise.  The other functions return 0 upon success.  A -1 re-
     turn value indicates an error occurred and the global variable errno is
     set to indicate the reason.

ERRORS
     These functions may fail if one of the following occurs:

     [EINVAL]      The specified signal signo is not a valid signal number.

SEE ALSO
     kill(2),  sigaction(2),  sigsuspend(2)

STANDARDS
     These functions are defined by IEEE Std1003.1-1990 (``POSIX'').

OpenBSD 2.6                      June 4, 1993                                1