.\" Copyright (c) 1990, 1991 The Regents of the University of California.
.\" All rights reserved.
.\"
.\" This code is derived from software contributed to Berkeley by
.\" the American National Standards Committee X3, on Information
.\" Processing Systems.
.\"
.\" 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. Neither the name of the University 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 REGENTS 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 REGENTS 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.
.\"
.\"	$OpenBSD: exit.3,v 1.11 2007/05/31 19:19:31 jmc Exp $
.\"
.Dd $Mdocdate: May 31 2007 $
.Dt EXIT 3
.Os
.Sh NAME
.Nm exit, _Exit
.Nd perform normal program termination
.Sh SYNOPSIS
.Fd #include <stdlib.h>
.Ft void
.Fn exit "int status"
.Ft void
.Fn _Exit "int status"
.Sh DESCRIPTION
The
.Fn exit
and
.Fn _Exit
functions terminate a process.
.Pp
Before termination,
.Fn exit
performs the following operations in the order listed:
.Bl -enum -offset indent
.It
Call the functions registered with the
.Xr atexit 3
function, in the reverse order of their registration.
.It
Flush all open output streams.
.It
Close all open streams.
.It
Unlink all files created with the
.Xr tmpfile 3
function.
.El
.Pp
The
.Fn _Exit
function terminates without calling the functions registered with the
.Xr atexit 3
function.
The
.Ox
implementation of
.Fn _Exit
does not flush open output streams or unlink files created with the
.Xr tmpfile 3
function.
However, this behavior is implementation-specific.
.Pp
Lastly,
.Fn exit
and
.Fn _Exit
call
.Xr _exit 2 .
Note that typically
.Xr _exit 2
only passes the lower 8 bits of
.Fa status
on to the parent, thus negative values have less meaning.
.Sh RETURN VALUES
The
.Fn exit
and
.Fn _Exit
functions never return.
.Sh SEE ALSO
.Xr _exit 2 ,
.Xr atexit 3 ,
.Xr intro 3 ,
.Xr sysexits 3 ,
.Xr tmpfile 3
.Sh STANDARDS
The
.Fn exit
and
.Fn _Exit
functions conform to
.St -ansiC-99 .