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.Dd September 8, 2016 29.Dt EXIT 2 30.Os 31.Sh NAME 32.Nm _exit 33.Nd terminate the calling process 34.Sh LIBRARY 35.Lb libc 36.Sh SYNOPSIS 37.In unistd.h 38.Ft void 39.Fn _exit "int status" 40.Sh DESCRIPTION 41The 42.Fn _exit 43system call 44terminates a process with the following consequences: 45.Bl -bullet 46.It 47All of the descriptors open in the calling process are closed. 48This may entail delays, for example, waiting for output to drain; 49a process in this state may not be killed, as it is already dying. 50.It 51If the parent process of the calling process has an outstanding 52.Xr wait 2 53call 54or catches the 55.Dv SIGCHLD 56signal, 57it is notified of the calling process's termination and 58the 59.Fa status 60is set as defined by 61.Xr wait 2 . 62.It 63The parent process-ID of all of the calling process's existing child 64processes are set to the process-ID of the calling process's reaper; 65the reaper (normally the initialization process) 66inherits each of these processes 67(see 68.Xr procctl 2 , 69.Xr init 8 70and the 71.Sx DEFINITIONS 72section of 73.Xr intro 2 ) . 74.It 75If the termination of the process causes any process group 76to become orphaned (usually because the parents of all members 77of the group have now exited; see 78.Dq orphaned process group 79in 80.Xr intro 2 ) , 81and if any member of the orphaned group is stopped, 82the 83.Dv SIGHUP 84signal and the 85.Dv SIGCONT 86signal are sent to all members of the newly-orphaned process group. 87.It 88If the process is a controlling process (see 89.Xr intro 2 ) , 90the 91.Dv SIGHUP 92signal is sent to the foreground process group of the controlling terminal, 93and all current access to the controlling terminal is revoked. 94.El 95.Pp 96Most C programs call the library routine 97.Xr exit 3 , 98which flushes buffers, closes streams, unlinks temporary files, etc., 99before 100calling 101.Fn _exit . 102.Sh RETURN VALUES 103The 104.Fn _exit 105system call 106can never return. 107.Sh SEE ALSO 108.Xr fork 2 , 109.Xr sigaction 2 , 110.Xr wait 2 , 111.Xr exit 3 , 112.Xr init 8 113.Sh STANDARDS 114The 115.Fn _exit 116system call is expected to conform to 117.St -p1003.1-90 . 118.Sh HISTORY 119The 120.Fn _exit 121function appeared in 122.At v7 . 123