1.\" $OpenBSD: kill.1,v 1.40 2020/02/09 00:21:01 jsg Exp $ 2.\" $NetBSD: kill.1,v 1.8 1995/09/07 06:30:26 jtc Exp $ 3.\" 4.\" Copyright (c) 1980, 1990, 1993 5.\" The Regents of the University of California. All rights reserved. 6.\" 7.\" This code is derived from software contributed to Berkeley by 8.\" the Institute of Electrical and Electronics Engineers, Inc. 9.\" 10.\" Redistribution and use in source and binary forms, with or without 11.\" modification, are permitted provided that the following conditions 12.\" are met: 13.\" 1. Redistributions of source code must retain the above copyright 14.\" notice, this list of conditions and the following disclaimer. 15.\" 2. Redistributions in binary form must reproduce the above copyright 16.\" notice, this list of conditions and the following disclaimer in the 17.\" documentation and/or other materials provided with the distribution. 18.\" 3. Neither the name of the University nor the names of its contributors 19.\" may be used to endorse or promote products derived from this software 20.\" without specific prior written permission. 21.\" 22.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32.\" SUCH DAMAGE. 33.\" 34.\" @(#)kill.1 8.2 (Berkeley) 4/28/95 35.\" 36.Dd $Mdocdate: February 9 2020 $ 37.Dt KILL 1 38.Os 39.Sh NAME 40.Nm kill 41.Nd terminate or signal a process 42.Sh SYNOPSIS 43.Nm kill 44.Op Fl s Ar signal_name 45.Ar pid ... 46.Nm kill 47.Fl l 48.Op Ar exit_status 49.Nm kill 50.Fl Ar signal_name 51.Ar pid ... 52.Nm kill 53.Fl Ar signal_number 54.Ar pid ... 55.Sh DESCRIPTION 56The 57.Nm 58utility sends a signal to the process(es) specified 59by the 60.Ar pid 61operand(s). 62If no signal is specified, 63.Dv SIGTERM 64is used. 65.Pp 66Only the superuser may send signals to other users' processes. 67.Pp 68The options are as follows: 69.Bl -tag -width Ds 70.It Fl l Op Ar exit_status 71Display the name of the signal corresponding to 72.Ar exit_status . 73.Ar exit_status 74may be the exit status of a command killed by a signal 75(see the 76special 77.Xr sh 1 78parameter 79.Sq ?\& ) 80or a signal number. 81.Pp 82If no operand is given, display the names of all the signals. 83.It Fl s Ar signal_name 84A symbolic signal name specifying the signal to be sent instead of the 85default 86.Dv SIGTERM . 87.It Fl Ar signal_name 88A symbolic signal name specifying the signal to be sent instead of the 89default 90.Dv SIGTERM . 91.It Fl Ar signal_number 92A non-negative decimal integer specifying the signal to be sent instead 93of the default 94.Dv SIGTERM . 95.El 96.Pp 97The following PIDs have special meanings: 98.Bl -tag -width Ds -offset indent 99.It \-1 100If superuser, broadcast the signal to all processes; otherwise, broadcast 101to all processes belonging to the user. 102.It 0 103Send the signal to all processes whose group ID is equal to the 104process group ID of the sender, and for which the process has permission. 105.It \- Ns Ar pgid 106Send the signal to all processes within the specified process group. 107.El 108.Pp 109Some of the more commonly used signals: 110.Pp 111.Bl -tag -width Ds -compact -offset indent 112.It 1 113HUP (hang up) 114.It 2 115INT (interrupt) 116.It 3 117QUIT (quit) 118.It 6 119ABRT (abort) 120.It 9 121KILL (non-catchable, non-ignorable kill) 122.It 14 123ALRM (alarm clock) 124.It 15 125TERM (software termination signal) 126.El 127.Pp 128For a more complete list, consult the 129.Xr sigaction 2 130manual page. 131.Pp 132A signal number of 0 133.Pq Li kill \-0 pid 134checks the validity of a certain PID, to see if it exists. 135An exit code of 0 means that the specified process exists. 136.Sh EXIT STATUS 137.Ex -std kill 138.Sh EXAMPLES 139Forcibly terminate process ID 1234: 140.Pp 141.Dl $ kill -9 1234 142.Pp 143Send the 144.Xr init 8 145process the hangup signal, instructing it to re-read 146.Xr ttys 5 : 147.Pp 148.Dl # kill -HUP 1 149.Sh SEE ALSO 150.Xr csh 1 , 151.Xr ksh 1 , 152.Xr pkill 1 , 153.Xr ps 1 , 154.Xr kill 2 , 155.Xr sigaction 2 156.Sh STANDARDS 157The 158.Nm 159utility is compliant with the 160.St -p1003.1-2008 161specification. 162.Pp 163The 164.Fl Ar signal_name 165and 166.Fl Ar signal_number 167syntax is marked by 168.St -p1003.1-2008 169as being an 170X/Open System Interfaces 171option. 172.Pp 173.Nm 174also exists as a built-in to 175.Xr csh 1 176and 177.Xr ksh 1 , 178though with a different syntax. 179.Sh HISTORY 180A 181.Nm 182command appeared in 183.At v3 . 184