1.\" $NetBSD: _exit.2,v 1.18 2003/09/08 17:54:34 wiz Exp $ 2.\" 3.\" Copyright (c) 1980, 1993 4.\" The Regents of the University of California. All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 3. Neither the name of the University nor the names of its contributors 15.\" may be used to endorse or promote products derived from this software 16.\" without specific prior written permission. 17.\" 18.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 19.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 22.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28.\" SUCH DAMAGE. 29.\" 30.\" @(#)_exit.2 8.1 (Berkeley) 6/4/93 31.\" 32.Dd April 23, 2002 33.Dt EXIT 2 34.Os 35.Sh NAME 36.Nm _Exit, _exit 37.Nd terminate the calling process 38.Sh LIBRARY 39.Lb libc 40.Sh SYNOPSIS 41.In stdlib.h 42.Ft void 43.Fn _Exit "int status" 44.In unistd.h 45.Ft void 46.Fn _exit "int status" 47.Sh DESCRIPTION 48The 49.Fn _Exit 50and 51.Fn _exit 52functions are equivalent. 53They each terminate a process with the following consequences: 54.Bl -bullet 55.It 56All of the descriptors open in the calling process are closed. 57This may entail delays, for example, waiting for output to drain; 58a process in this state may not be killed, as it is already dying. 59.It 60If the parent process of the calling process has an outstanding 61.Xr wait 2 62call 63or catches the 64.Dv SIGCHLD 65signal, 66it is notified of the calling process's termination and 67the 68.Em status 69is set as defined by 70.Xr wait 2 . 71.It 72The parent process-ID of all of the calling process's existing child 73processes are set to 1; the initialization process 74(see the DEFINITIONS section of 75.Xr intro 2 ) 76inherits each of these processes. 77.It 78If the termination of the process causes any process group 79to become orphaned (usually because the parents of all members 80of the group have now exited; see 81.Dq orphaned process group 82in 83.Xr intro 2 ) , 84and if any member of the orphaned group is stopped, 85the 86.Dv SIGHUP 87signal and the 88.Dv SIGCONT 89signal are sent to all members of the newly-orphaned process group. 90.It 91If the process is a controlling process (see 92.Xr intro 2 ) , 93the 94.Dv SIGHUP 95signal is sent to the foreground process group of the controlling terminal, 96and all current access to the controlling terminal is revoked. 97.El 98.Pp 99Most C programs call the library routine 100.Xr exit 3 , 101which flushes buffers, closes streams, unlinks temporary files, etc., 102before 103calling 104.Fn _exit . 105.Sh RETURN VALUES 106.Fn _Exit 107and 108.Fn _exit 109can never return. 110.Sh SEE ALSO 111.Xr fork 2 , 112.Xr sigaction 2 , 113.Xr wait 2 , 114.Xr exit 3 115.Sh STANDARDS 116The 117.Fn _exit 118function conforms to 119.St -p1003.1-90 . 120The 121.Fn _Exit 122function conforms to 123.St -isoC-99 . 124