NAME
sigdelset — delete
a signal from a signal set
SYNOPSIS
int sigdelset(sigset_t *set, int signo);
DESCRIPTION
The sigdelset () function deletes the
individual signal specified by
signo
from the signal set pointed to by
set.
Applications should call either
sigemptyset(3) or sigfillset(3) 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(3), sigaction(3),
sigaddset(3), sigdelset (),
sigismember(3), sigpending(3),
sigprocmask(3), sigsuspend(3),
sigtimedwait(3), sigwait(3), or
sigwaitinfo(3), the results are undefined.
RETURN VALUE
Upon successful completion, sigdelset ()
shall return 0; otherwise, it shall return -1 and set
errno to
indicate the error.
ERRORS
The sigdelset () function may fail if:
- [EINVAL]
- The signo argument is not a valid signal number, or is an unsupported signal number.
EXAMPLES
None.
APPLICATION USAGE
None.
RATIONALE
None.
FUTURE DIRECTIONS
None.
SEE ALSO
xsh_chap02_04(3), sigaction(3), sigaddset(3), sigemptyset(3), sigfillset(3), sigismember(3), sigpending(3), sigprocmask(3), sigsuspend(3), the Base Definitions volume of IEEE Std 1003.1-2001 (“POSIX.1”), <signal.h>
CHANGE HISTORY
First released in Issue 3. Included for alignment with the POSIX.1-1988 standard.
Issue 5
The last paragraph of the DESCRIPTION was included as an APPLICATION USAGE note in previous issues.
Issue 6
The SYNOPSIS is marked CX since the presence of this function in the <signal.h> header is an extension over the ISO C standard.
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