.\" Copyright (c) 1994 Mike Battersby
.\"
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.\" Modified by aeb, 960721
.\"
.TH SIGSETOPS 3 "24 September 1994" "Linux 1.0" "Linux Programmer's Manual"

.SH NAME
sigemptyset, sigfillset, sigaddset, sigdelset, sigismember \- POSIX
signal set operations.

.SH SYNOPSIS
.B #include <signal.h>
.sp 2
.BI "int sigemptyset(sigset_t *" set );
.sp
.BI "int sigfillset(sigset_t *" set );
.sp
.BI "int sigaddset(sigset_t *" set ", int " signum );
.sp
.BI "int sigdelset(sigset_t *" set ", int " signum );
.sp
.BI "int sigismember(const sigset_t *" set ", int " signum );

.SH DESCRIPTION
The
.BR sigsetops (3)
functions allow the manipulation of POSIX signal sets.
.PP
.B sigemptyset
initializes the signal set given by
.I set
to empty, with all signals excluded from the set.
.PP
.B sigfillset
initializes 
.I set
to full, including all signals.
.PP
.B sigaddset 
and
.B sigdelset
add and delete respectively signal
.I signum
from 
.IR set .
.PP
.B sigismember
tests whether
.I signum
is a member of 
.I set.

.SH "RETURN VALUES"
.BR sigemptyset ", " sigfullset ", " sigaddset
and
.B sigdelset 
return 0 on success and -1 on error.
.PP
.B sigismember
returns 1 if
.I signum
is a member of
.IR set ,
0 if
.I signum
is not a member, and -1 on error.

.SH ERRORS
.TP
.B EINVAL
.I sig
is not a valid signal.

.SH "CONFORMING TO"
POSIX

.SH "SEE ALSO"
.BR sigaction "(2), " sigpending "(2), " sigprocmask "(2), " 
.BR sigsuspend "(2)"