1.\" $OpenBSD: chown.8,v 1.23 2019/09/06 19:25:08 schwarze Exp $ 2.\" 3.\" Copyright (c) 1990, 1991, 1993, 1994 4.\" The Regents of the University of California. All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 3. Neither the name of the University nor the names of its contributors 15.\" may be used to endorse or promote products derived from this software 16.\" without specific prior written permission. 17.\" 18.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 19.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 22.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28.\" SUCH DAMAGE. 29.\" 30.\" from: @(#)chown.8 8.3 (Berkeley) 3/31/94 31.\" 32.Dd $Mdocdate: September 6 2019 $ 33.Dt CHOWN 8 34.Os 35.Sh NAME 36.Nm chown 37.Nd change file owner and group 38.Sh SYNOPSIS 39.Nm chown 40.Op Fl h 41.Oo 42.Fl R 43.Op Fl H | L | P 44.Oc 45.Ar owner Ns Op : Ns Ar group 46.Ar 47.Nm chown 48.Op Fl h 49.Oo 50.Fl R 51.Op Fl H | L | P 52.Oc 53.Pf : Ar group 54.Ar 55.Sh DESCRIPTION 56.Nm 57sets the user ID and/or the group ID of the specified files. 58.Pp 59The options are as follows: 60.Bl -tag -width Ds 61.It Fl H 62If the 63.Fl R 64option is specified, symbolic links on the command line are followed. 65Symbolic links encountered in the tree traversal are not followed. 66.It Fl h 67Treat symbolic links like other files: modify links instead of 68following them. 69The 70.Fl h 71and 72.Fl R 73options are mutually exclusive. 74.It Fl L 75If the 76.Fl R 77option is specified, all symbolic links are followed. 78.It Fl P 79If the 80.Fl R 81option is specified, no symbolic links are followed. 82.It Fl R 83Recurse. 84Where 85.Ar file 86is a directory, 87change the user ID and/or the group ID of the directory 88and all the files and directories in the file hierarchy below it. 89.El 90.Pp 91The 92.Fl H , 93.Fl L , 94and 95.Fl P 96options are ignored unless the 97.Fl R 98option is specified; 99if none of them are given, 100the default is to not follow symbolic links. 101In addition, these options override each other and the 102command's actions are determined by the last one specified. 103.Pp 104The 105.Ar owner 106and 107.Ar group 108operands are both optional; however, one must be specified. 109If the 110.Ar group 111operand is specified, it must be preceded by a colon 112.Pq Sq \&: 113character. 114.Pp 115The 116.Ar owner 117may be either a numeric user ID or a user name. 118If a user name is also a numeric user ID, the operand is used as a 119user name. 120The 121.Ar group 122may be either a numeric group ID or a group name. 123If a group name is also a numeric group ID, the operand is used as a 124group name. 125.Pp 126By default, 127.Nm 128clears the set-user-ID and set-group-ID bits on the file 129to prevent accidental or mischievous creation of 130set-user-ID and set-group-ID programs. 131This behaviour can be overridden by setting the 132.Xr sysctl 8 133variable 134.Va fs.posix.setuid 135to zero. 136.Pp 137Only the superuser is permitted to change the owner of a file. 138.Sh EXIT STATUS 139.Ex -std chown 140.Sh SEE ALSO 141.Xr chgrp 1 , 142.Xr find 1 , 143.Xr chown 2 , 144.Xr fts_open 3 , 145.Xr symlink 7 146.Sh STANDARDS 147The 148.Nm 149utility is compliant with the 150.St -p1003.1-2008 151specification. 152.Pp 153The ability to specify 154.Ar group 155without 156.Ar owner 157is an extension to that specification. 158.Pp 159Some 160.Pf non- Bx 161systems may allow the (non-privileged) owner of a file to change 162its ownership. 163.Pp 164Previous versions of the 165.Nm 166utility used the dot 167.Pq Sq \&. 168character to distinguish the group name. 169This was changed when the utility was first standardised in 170.St -p1003.2-92 171to be a colon 172.Pq Sq \&: 173character to allow user and group names to contain the dot 174character, though the dot separator still remains supported 175due to widely required backwards compatibility. 176.Sh HISTORY 177A 178.Nm 179command appeared in 180.At v1 . 181