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.\" 4. Neither the name of the University nor the names of its contributors 17.\" may be used to endorse or promote products derived from this software 18.\" without specific prior written permission. 19.\" 20.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30.\" SUCH DAMAGE. 31.\" 32.\" @(#)exit.3 8.1 (Berkeley) 6/4/93 33.\" $FreeBSD: src/lib/libc/stdlib/exit.3,v 1.16 2007/01/09 00:28:09 imp Exp $ 34.\" $DragonFly: src/lib/libc/stdlib/exit.3,v 1.3 2007/06/15 19:36:33 swildner Exp $ 35.\" 36.Dd June 15, 2007 37.Dt EXIT 3 38.Os 39.Sh NAME 40.Nm exit , 41.Nm _Exit 42.Nd perform normal program termination 43.Sh LIBRARY 44.Lb libc 45.Sh SYNOPSIS 46.In stdlib.h 47.Ft void 48.Fn exit "int status" 49.Ft void 50.Fn _Exit "int status" 51.Sh DESCRIPTION 52The 53.Fn exit 54and 55.Fn _Exit 56functions terminate a process. 57.Pp 58Before termination, 59.Fn exit 60performs the following functions in the order listed: 61.Bl -enum -offset indent 62.It 63Call the functions registered with the 64.Xr atexit 3 65function, in the reverse order of their registration. 66.It 67Flush all open output streams. 68.It 69Close all open streams. 70.It 71Unlink all files created with the 72.Xr tmpfile 3 73function. 74.El 75.Pp 76The 77.Fn _Exit 78function terminates without calling the functions registered with the 79.Xr atexit 3 80function, and may or may not perform the other actions listed. 81Both functions make the low-order eight bits of the 82.Fa status 83argument available to a parent process which has called a 84.Xr wait 2 Ns -family 85function. 86.Pp 87The C Standard 88.Pq St -isoC-99 89defines the values 90.Li 0 , 91.Dv EXIT_SUCCESS , 92and 93.Dv EXIT_FAILURE 94as possible values of 95.Fa status . 96Cooperating processes may use other values; 97in a program which might be called by a mail transfer agent, the 98values described in 99.Xr sysexits 3 100may be used to provide more information to the parent process. 101.Pp 102Note that 103.Fn exit 104does nothing to prevent bottomless recursion should a function registered 105using 106.Xr atexit 3 107itself call 108.Fn exit . 109Such functions must call 110.Fn _Exit 111instead (although this has other effects as well which may not be desired). 112.Sh RETURN VALUES 113The 114.Fn exit 115and 116.Fn _Exit 117functions 118never return. 119.Sh SEE ALSO 120.Xr _exit 2 , 121.Xr wait 2 , 122.Xr atexit 3 , 123.Xr intro 3 , 124.Xr sysexits 3 , 125.Xr tmpfile 3 126.Sh STANDARDS 127The 128.Fn exit 129and 130.Fn _Exit 131functions conform to 132.St -isoC-99 . 133