.\"	$NetBSD: raise_default_signal.3,v 1.1 2007/09/25 01:13:56 lukem Exp $
.\"
.\" Copyright (c) 2007 The NetBSD Foundation, Inc.
.\" All rights reserved.
.\"
.\" This code is derived from software contributed to The NetBSD Foundation
.\" by Luke Mewburn.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\" 3. All advertising materials mentioning features or use of this software
.\"    must display the following acknowledgement:
.\"        This product includes software developed by the NetBSD
.\"        Foundation, Inc. and its contributors.
.\" 4. Neither the name of The NetBSD Foundation nor the names of its
.\"    contributors may be used to endorse or promote products derived
.\"    from this software without specific prior written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
.\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
.\" TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
.\" PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
.\" BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
.\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
.\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
.\" POSSIBILITY OF SUCH DAMAGE.
.\"
.Dd September 25, 2007
.Dt RAISE_DEFAULT_SIGNAL 3
.Os
.Sh NAME
.Nm raise_default_signal
.Nd raise the default signal handler
.Sh LIBRARY
.Lb libutil
.Sh SYNOPSIS
.In util.h
.Ft int
.Fo raise_default_signal
.Fa "int sig"
.Fc
.Sh DESCRIPTION
The
.Fn raise_default_signal
function raises the default signal handler for the signal
.Fa sig .
This function may be used by a user-defined signal handler router
to ensure that a parent process receives the correct notification
of a process termination by a signal.
This can be used to avoid a common programming mistake
when terminating a process from a custom
.Dv SIGINT
or
.Dv SIGQUIT
signal handler.
.Pp
The operations performed are:
.Bl -enum -offset indent
.It
Block all signals, using
.Xr sigprocmask 3 .
.It
Set the signal handler for signal
.Fa sig
to the default signal handler
.Dv ( SIG_DFL ) .
.It
.Xr raise 3
signal
.Fa sig .
.It
Unblock signal
.Fa sig
to deliver it.
.It
Restore the original signal mask and handler,
even if there was a failure.
.El
.Pp
See
.Xr signal 7
for a table of signals and default actions.
.Pp
The
.Fn raise_default_signal
function should be async-signal-safe.
.Sh RETURN VALUES
Upon successful completion, a value of 0 is returned.
Otherwise, a value of \-1 is returned and the global variable
.Va errno
is set to indicate the error.
.Sh ERRORS
The
.Fn raise_default_signal
function may fail and set
.Va errno
for any of the errors specified for the functions
.Xr sigemptyset 3 ,
.Xr sigfillset 3 ,
.Xr sigaddset 3 ,
.Xr sigprocmask 2 ,
.Xr sigaction 2 ,
or
.Xr raise 3 .
.Sh SEE ALSO
.Xr sigaction 2 ,
.Xr sigprocmask 2 ,
.Xr raise 3 ,
.Xr signal 7
.Sh HISTORY
The
.Fn raise_default_signal
function first appeared in
.Nx 5.0 .