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.\" 30.Dd September 8, 2016 31.Dt EXIT 2 32.Os 33.Sh NAME 34.Nm _exit 35.Nd terminate the calling process 36.Sh LIBRARY 37.Lb libc 38.Sh SYNOPSIS 39.In unistd.h 40.Ft void 41.Fn _exit "int status" 42.Sh DESCRIPTION 43The 44.Fn _exit 45system call 46terminates a process with the following consequences: 47.Bl -bullet 48.It 49All of the descriptors open in the calling process are closed. 50This may entail delays, for example, waiting for output to drain; 51a process in this state may not be killed, as it is already dying. 52.It 53If the parent process of the calling process has an outstanding 54.Xr wait 2 55call 56or catches the 57.Dv SIGCHLD 58signal, 59it is notified of the calling process's termination and 60the 61.Fa status 62is set as defined by 63.Xr wait 2 . 64.It 65The parent process-ID of all of the calling process's existing child 66processes are set to the process-ID of the calling process's reaper; 67the reaper (normally the initialization process) 68inherits each of these processes 69(see 70.Xr procctl 2 , 71.Xr init 8 72and the 73.Sx DEFINITIONS 74section of 75.Xr intro 2 ) . 76.It 77If the termination of the process causes any process group 78to become orphaned (usually because the parents of all members 79of the group have now exited; see 80.Dq orphaned process group 81in 82.Xr intro 2 ) , 83and if any member of the orphaned group is stopped, 84the 85.Dv SIGHUP 86signal and the 87.Dv SIGCONT 88signal are sent to all members of the newly-orphaned process group. 89.It 90If the process is a controlling process (see 91.Xr intro 2 ) , 92the 93.Dv SIGHUP 94signal is sent to the foreground process group of the controlling terminal, 95and all current access to the controlling terminal is revoked. 96.El 97.Pp 98Most C programs call the library routine 99.Xr exit 3 , 100which flushes buffers, closes streams, unlinks temporary files, etc., 101before 102calling 103.Fn _exit . 104.Sh RETURN VALUES 105The 106.Fn _exit 107system call 108can never return. 109.Sh SEE ALSO 110.Xr fork 2 , 111.Xr sigaction 2 , 112.Xr wait 2 , 113.Xr exit 3 , 114.Xr init 8 115.Sh STANDARDS 116The 117.Fn _exit 118system call is expected to conform to 119.St -p1003.1-90 . 120.Sh HISTORY 121The 122.Fn _exit 123function appeared in 124.At v7 . 125