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.\" 4. 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 June 4, 1993 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 1; the initialization process 68inherits each of these processes 69(see 70.Xr init 8 71and the 72.Sx DEFINITIONS 73section of 74.Xr intro 2 ) . 75.It 76If the termination of the process causes any process group 77to become orphaned (usually because the parents of all members 78of the group have now exited; see 79.Dq orphaned process group 80in 81.Xr intro 2 ) , 82and if any member of the orphaned group is stopped, 83the 84.Dv SIGHUP 85signal and the 86.Dv SIGCONT 87signal are sent to all members of the newly-orphaned process group. 88.It 89If the process is a controlling process (see 90.Xr intro 2 ) , 91the 92.Dv SIGHUP 93signal is sent to the foreground process group of the controlling terminal, 94and all current access to the controlling terminal is revoked. 95.El 96.Pp 97Most C programs call the library routine 98.Xr exit 3 , 99which flushes buffers, closes streams, unlinks temporary files, etc., 100before 101calling 102.Fn _exit . 103.Sh RETURN VALUES 104The 105.Fn _exit 106system call 107can never return. 108.Sh SEE ALSO 109.Xr fork 2 , 110.Xr sigaction 2 , 111.Xr wait 2 , 112.Xr exit 3 , 113.Xr init 8 114.Sh STANDARDS 115The 116.Fn _exit 117system call is expected to conform to 118.St -p1003.1-90 . 119.Sh HISTORY 120The 121.Fn _exit 122function appeared in 123.At v7 . 124