1.\" Copyright (c) 1990, 1991 The Regents of the University of California. 2.\" 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.\" $OpenBSD: exit.3,v 1.12 2011/11/17 14:26:14 schwarze Exp $ 33.\" 34.Dd $Mdocdate: November 17 2011 $ 35.Dt EXIT 3 36.Os 37.Sh NAME 38.Nm exit, _Exit 39.Nd perform normal program termination 40.Sh SYNOPSIS 41.Fd #include <stdlib.h> 42.Ft void 43.Fn exit "int status" 44.Ft void 45.Fn _Exit "int status" 46.Sh DESCRIPTION 47The 48.Fn exit 49and 50.Fn _Exit 51functions terminate a process. 52.Pp 53Before termination, 54.Fn exit 55performs the following operations in the order listed: 56.Bl -enum -offset indent 57.It 58Call the functions registered with the 59.Xr atexit 3 60function, in the reverse order of their registration. 61.It 62Flush all open output streams. 63.It 64Close all open streams. 65.It 66Unlink all files created with the 67.Xr tmpfile 3 68function. 69.El 70.Pp 71The 72.Fn _Exit 73function terminates without calling the functions registered with the 74.Xr atexit 3 75function. 76The 77.Ox 78implementation of 79.Fn _Exit 80does not flush open output streams or unlink files created with the 81.Xr tmpfile 3 82function. 83However, this behavior is implementation-specific. 84.Pp 85Lastly, 86.Fn exit 87and 88.Fn _Exit 89call 90.Xr _exit 2 . 91Note that typically 92.Xr _exit 2 93only passes the lower 8 bits of 94.Fa status 95on to the parent, thus negative values have less meaning. 96.Sh RETURN VALUES 97The 98.Fn exit 99and 100.Fn _Exit 101functions never return. 102.Sh SEE ALSO 103.Xr _exit 2 , 104.Xr atexit 3 , 105.Xr intro 3 , 106.Xr sysexits 3 , 107.Xr tmpfile 3 108.Sh STANDARDS 109The 110.Fn exit 111and 112.Fn _Exit 113functions conform to 114.St -ansiC-99 . 115.Sh HISTORY 116An 117.Fn exit 118function first appeared as a system call in 119.At v1 . 120In 121.At v7 , 122the bare system call was renamed to 123.Xr _exit 2 . 124