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. All advertising materials mentioning features or use of this software 13.\" must display the following acknowledgement: 14.\" This product includes software developed by the University of 15.\" California, Berkeley and its contributors. 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.2 8.1 (Berkeley) 6/4/93 33.\" $FreeBSD$ 34.\" 35.Dd June 4, 1993 36.Dt EXIT 2 37.Os 38.Sh NAME 39.Nm _exit 40.Nd terminate the calling process 41.Sh LIBRARY 42.Lb libc 43.Sh SYNOPSIS 44.In unistd.h 45.Ft void 46.Fn _exit "int status" 47.Sh DESCRIPTION 48The 49.Fn _exit 50system call 51terminates a process with the following consequences: 52.Bl -bullet 53.It 54All of the descriptors open in the calling process are closed. 55This may entail delays, for example, waiting for output to drain; 56a process in this state may not be killed, as it is already dying. 57.It 58If the parent process of the calling process has an outstanding 59.Xr wait 2 60call 61or catches the 62.Dv SIGCHLD 63signal, 64it is notified of the calling process's termination and 65the 66.Fa status 67is set as defined by 68.Xr wait 2 . 69.It 70The parent process-ID of all of the calling process's existing child 71processes are set to 1; the initialization process 72inherits each of these processes 73(see 74.Xr init 8 75and the 76.Sx DEFINITIONS 77section of 78.Xr intro 2 ) . 79.It 80If the termination of the process causes any process group 81to become orphaned (usually because the parents of all members 82of the group have now exited; see 83.Dq orphaned process group 84in 85.Xr intro 2 ) , 86and if any member of the orphaned group is stopped, 87the 88.Dv SIGHUP 89signal and the 90.Dv SIGCONT 91signal are sent to all members of the newly-orphaned process group. 92.It 93If the process is a controlling process (see 94.Xr intro 2 ) , 95the 96.Dv SIGHUP 97signal is sent to the foreground process group of the controlling terminal, 98and all current access to the controlling terminal is revoked. 99.El 100.Pp 101Most C programs call the library routine 102.Xr exit 3 , 103which flushes buffers, closes streams, unlinks temporary files, etc., 104before 105calling 106.Fn _exit . 107.Sh RETURN VALUES 108The 109.Fn _exit 110system call 111can never return. 112.Sh SEE ALSO 113.Xr fork 2 , 114.Xr sigaction 2 , 115.Xr wait 2 , 116.Xr exit 3 , 117.Xr init 8 118.Sh STANDARDS 119The 120.Fn _exit 121system call is expected to conform to 122.St -p1003.1-90 . 123.Sh HISTORY 124The 125.Fn _exit 126function appeared in 127.At v7 . 128