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(),
sigaction(), 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 Technology
-- 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 .