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.\" $FreeBSD$ 34.\" 35.Dd September 9, 2002 36.Dt EXIT 3 37.Os 38.Sh NAME 39.Nm exit , _Exit 40.Nd perform normal program termination 41.Sh LIBRARY 42.Lb libc 43.Sh SYNOPSIS 44.In stdlib.h 45.Ft void 46.Fn exit "int status" 47.Ft void 48.Fn _Exit "int status" 49.Sh DESCRIPTION 50The 51.Fn exit 52and 53.Fn _Exit 54functions terminate a process. 55.Pp 56Before termination, 57.Fn exit 58performs the following functions in the order listed: 59.Bl -enum -offset indent 60.It 61Call the functions registered with the 62.Xr atexit 3 63function, in the reverse order of their registration. 64.It 65Flush all open output streams. 66.It 67Close all open streams. 68.It 69Unlink all files created with the 70.Xr tmpfile 3 71function. 72.El 73.Pp 74The 75.Fn _Exit 76function terminates without calling the functions registered with the 77.Xr atexit 3 78function, and may or may not perform the other actions listed. 79Both functions make the low-order eight bits of the 80.Fa status 81argument available to a parent process which has called a 82.Xr wait 2 Ns -family 83function. 84.Pp 85The C Standard 86.Pq St -isoC-99 87defines the values 88.Li 0 , 89.Dv EXIT_SUCCESS , 90and 91.Dv EXIT_FAILURE 92as possible values of 93.Fa status . 94Cooperating processes may use other values; 95in a program which might be called by a mail transfer agent, the 96values described in 97.Xr sysexits 3 98may be used to provide more information to the parent process. 99.Pp 100Note that 101.Fn exit 102does nothing to prevent bottomless recursion should a function registered 103using 104.Xr atexit 3 105itself call 106.Fn exit . 107Such functions must call 108.Fn _Exit 109instead (although this has other effects as well which may not be desired). 110.Sh RETURN VALUES 111The 112.Fn exit 113and 114.Fn _Exit 115functions 116never return. 117.Sh SEE ALSO 118.Xr _exit 2 , 119.Xr wait 2 , 120.Xr atexit 3 , 121.Xr intro 3 , 122.Xr sysexits 3 , 123.Xr tmpfile 3 124.Sh STANDARDS 125The 126.Fn exit 127and 128.Fn _Exit 129functions conform to 130.St -isoC-99 . 131