NAME    [Toc]    [Back]

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

LIBRARY    [Toc]    [Back]

     Standard C Library (libc, -lc)

SYNOPSIS    [Toc]    [Back]

     #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    [Toc]    [Back]

     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.

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

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


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

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

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

     sigemptyset() and sigfillset() are provided as macros, but actual functions
 are available if their names are undefined (with #undef name).

RETURN VALUES    [Toc]    [Back]

     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
     return value indicates an error occurred and the global variable errno is
     set to indicate the reason.

ERRORS    [Toc]    [Back]

     These functions could fail if one of the following occurs:

     [EINVAL]           signo has an invalid value.

SEE ALSO    [Toc]    [Back]

     kill(2), sigaction(2), sigsuspend(2), signal(7)

STANDARDS    [Toc]    [Back]

     These functions conform to ISO/IEC 9945-1:1990 (``POSIX.1'').

BSD                              June 4, 1993                              BSD