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. 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.\" 35.Dd June 15, 2007 36.Dt EXIT 3 37.Os 38.Sh NAME 39.Nm exit , 40.Nm _Exit 41.Nd perform normal program termination 42.Sh LIBRARY 43.Lb libc 44.Sh SYNOPSIS 45.In stdlib.h 46.Ft void 47.Fn exit "int status" 48.Ft void 49.Fn _Exit "int status" 50.Sh DESCRIPTION 51The 52.Fn exit 53and 54.Fn _Exit 55functions terminate a process. 56.Pp 57Before termination, 58.Fn exit 59performs the following functions in the order listed: 60.Bl -enum -offset indent 61.It 62Call the functions registered with the 63.Xr atexit 3 64function, in the reverse order of their registration. 65.It 66Flush all open output streams. 67.It 68Close all open streams. 69.It 70Unlink all files created with the 71.Xr tmpfile 3 72function. 73.El 74.Pp 75The 76.Fn _Exit 77function terminates without calling the functions registered with the 78.Xr atexit 3 79function, and may or may not perform the other actions listed. 80Both functions make the low-order eight bits of the 81.Fa status 82argument available to a parent process which has called a 83.Xr wait 2 Ns -family 84function. 85.Pp 86The C Standard 87.Pq St -isoC-99 88defines the values 89.Li 0 , 90.Dv EXIT_SUCCESS , 91and 92.Dv EXIT_FAILURE 93as possible values of 94.Fa status . 95Cooperating processes may use other values; 96in a program which might be called by a mail transfer agent, the 97values described in 98.Xr sysexits 3 99may be used to provide more information to the parent process. 100.Pp 101Note that 102.Fn exit 103does nothing to prevent bottomless recursion should a function registered 104using 105.Xr atexit 3 106itself call 107.Fn exit . 108Such functions must call 109.Fn _Exit 110instead (although this has other effects as well which may not be desired). 111.Sh RETURN VALUES 112The 113.Fn exit 114and 115.Fn _Exit 116functions 117never return. 118.Sh SEE ALSO 119.Xr _exit 2 , 120.Xr wait 2 , 121.Xr atexit 3 , 122.Xr at_quick_exit 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