1.\" Copyright (c) 1980, 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 3. Neither the name of the University nor the names of its contributors 13.\" may be used to endorse or promote products derived from this software 14.\" without specific prior written permission. 15.\" 16.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 17.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 20.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26.\" SUCH DAMAGE. 27.\" 28.\" @(#)_exit.2 8.1 (Berkeley) 6/4/93 29.\" $FreeBSD$ 30.\" 31.Dd September 8, 2016 32.Dt EXIT 2 33.Os 34.Sh NAME 35.Nm _exit 36.Nd terminate the calling process 37.Sh LIBRARY 38.Lb libc 39.Sh SYNOPSIS 40.In unistd.h 41.Ft void 42.Fn _exit "int status" 43.Sh DESCRIPTION 44The 45.Fn _exit 46system call 47terminates a process with the following consequences: 48.Bl -bullet 49.It 50All of the descriptors open in the calling process are closed. 51This may entail delays, for example, waiting for output to drain; 52a process in this state may not be killed, as it is already dying. 53.It 54If the parent process of the calling process has an outstanding 55.Xr wait 2 56call 57or catches the 58.Dv SIGCHLD 59signal, 60it is notified of the calling process's termination and 61the 62.Fa status 63is set as defined by 64.Xr wait 2 . 65.It 66The parent process-ID of all of the calling process's existing child 67processes are set to the process-ID of the calling process's reaper; 68the reaper (normally the initialization process) 69inherits each of these processes 70(see 71.Xr procctl 2 , 72.Xr init 8 73and the 74.Sx DEFINITIONS 75section of 76.Xr intro 2 ) . 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 106The 107.Fn _exit 108system call 109can never return. 110.Sh SEE ALSO 111.Xr fork 2 , 112.Xr sigaction 2 , 113.Xr wait 2 , 114.Xr exit 3 , 115.Xr init 8 116.Sh STANDARDS 117The 118.Fn _exit 119system call is expected to conform to 120.St -p1003.1-90 . 121.Sh HISTORY 122The 123.Fn _exit 124function appeared in 125.At v7 . 126