1.\" Copyright (c) 1990, 1991, 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" This code is derived from software contributed to Berkeley by 5.\" the American National Standards Committee X3, on Information 6.\" Processing Systems. 7.\" 8.\" Redistribution and use in source and binary forms, with or without 9.\" modification, are permitted provided that the following conditions 10.\" are met: 11.\" 1. Redistributions of source code must retain the above copyright 12.\" notice, this list of conditions and the following disclaimer. 13.\" 2. Redistributions in binary form must reproduce the above copyright 14.\" notice, this list of conditions and the following disclaimer in the 15.\" documentation and/or other materials provided with the distribution. 16.\" 3. All advertising materials mentioning features or use of this software 17.\" must display the following acknowledgement: 18.\" This product includes software developed by the University of 19.\" California, Berkeley and its contributors. 20.\" 4. Neither the name of the University nor the names of its contributors 21.\" may be used to endorse or promote products derived from this software 22.\" without specific prior written permission. 23.\" 24.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34.\" SUCH DAMAGE. 35.\" 36.\" @(#)exit.3 8.1 (Berkeley) 6/4/93 37.\" $FreeBSD$ 38.\" 39.Dd September 9, 2002 40.Dt EXIT 3 41.Os 42.Sh NAME 43.Nm exit , _Exit 44.Nd perform normal program termination 45.Sh LIBRARY 46.Lb libc 47.Sh SYNOPSIS 48.In stdlib.h 49.Ft void 50.Fn exit "int status" 51.Ft void 52.Fn _Exit "int status" 53.Sh DESCRIPTION 54The 55.Fn exit 56and 57.Fn _Exit 58functions terminate a process. 59.Pp 60Before termination, 61.Fn exit 62performs the following functions in the order listed: 63.Bl -enum -offset indent 64.It 65Call the functions registered with the 66.Xr atexit 3 67function, in the reverse order of their registration. 68.It 69Flush all open output streams. 70.It 71Close all open streams. 72.It 73Unlink all files created with the 74.Xr tmpfile 3 75function. 76.El 77.Pp 78The 79.Fn _Exit 80function terminates without calling the functions registered with the 81.Xr atexit 3 82function, and may or may not perform the other actions listed. 83Both functions make the low-order eight bits of the 84.Fa status 85argument available to a parent process which has called a 86.Xr wait 2 Ns -family 87function. 88.Pp 89The C Standard 90.Pq St -isoC-99 91defines the values 92.Li 0 , 93.Dv EXIT_SUCCESS , 94and 95.Dv EXIT_FAILURE 96as possible values of 97.Fa status . 98Cooperating processes may use other values; 99in a program which might be called by a mail transfer agent, the 100values described in 101.Xr sysexits 3 102may be used to provide more information to the parent process. 103.Pp 104Note that 105.Fn exit 106does nothing to prevent bottomless recursion should a function registered 107using 108.Xr atexit 3 109itself call 110.Fn exit . 111Such functions must call 112.Fn _Exit 113instead (although this has other effects as well which may not be desired). 114.Sh RETURN VALUES 115The 116.Fn exit 117and 118.Fn _Exit 119functions 120never return. 121.Sh SEE ALSO 122.Xr _exit 2 , 123.Xr wait 2 , 124.Xr atexit 3 , 125.Xr intro 3 , 126.Xr sysexits 3 , 127.Xr tmpfile 3 128.Sh STANDARDS 129The 130.Fn exit 131and 132.Fn _Exit 133functions conform to 134.St -isoC-99 . 135