posix man page for sigaddset

SIGADDSET(P)						     POSIX Programmer's Manual						      SIGADDSET(P)

NAME
       sigaddset - add a signal to a signal set

SYNOPSIS
       #include <signal.h>

       int sigaddset(sigset_t *set, int signo);

DESCRIPTION
       The sigaddset() function adds the individual signal specified by the signo to the signal set pointed to by set.

       Applications  shall call either sigemptyset() or sigfillset() at least once for each object of type sigset_t prior to any other use of that
       object. If such an object is not initialized in this way, but is nonetheless supplied as an argument to any  of	pthread_sigmask(),  sigac-
       tion(),	sigaddset(),  sigdelset(),  sigismember(), sigpending(), sigprocmask(), sigsuspend(), sigtimedwait(), sigwait(), or sigwaitinfo(),
       the results are undefined.

RETURN VALUE
       Upon successful completion, sigaddset() shall return 0; otherwise, it shall return -1 and set errno to indicate the error.

ERRORS
       The sigaddset() function may fail if:

       EINVAL The value of the signo argument is an invalid or unsupported signal number.

       The following sections are informative.

EXAMPLES
       None.

APPLICATION USAGE
       None.

RATIONALE
       None.

FUTURE DIRECTIONS
       None.

SEE ALSO
       Signal Concepts , sigaction() , sigdelset() , sigemptyset() , sigfillset() , sigismember() , sigpending() , sigprocmask() , sigsuspend()  ,
       the Base Definitions volume of IEEE Std 1003.1-2001, <signal.h>

COPYRIGHT
       Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003 Edition, Standard for Information Technol-
       ogy -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of
       Electrical  and	Electronics  Engineers, Inc and The Open Group. In the event of any discrepancy between this version and the original IEEE
       and The Open Group Standard, the original IEEE and The Open Group Standard is the referee document. The original Standard can  be  obtained
       online at http://www.opengroup.org/unix/online.html .

IEEE
/The Open Group						       2003							      SIGADDSET(P)