1.\" $OpenBSD: chown.8,v 1.18 2014/01/23 08:18:12 jmc 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: January 23 2014 $ 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 : Ns 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 67Change the user ID and/or the group ID on symbolic links. 68The 69.Fl R 70and 71.Fl h 72options are mutually exclusive. 73.It Fl L 74If the 75.Fl R 76option is specified, all symbolic links are followed. 77.It Fl P 78If the 79.Fl R 80option is specified, no symbolic links are followed. 81.It Fl R 82Recurse. 83Where 84.Ar file 85is a directory, 86change the user ID and/or the group ID of the directory 87and all the files and directories in the file hierarchy below it. 88.El 89.Pp 90The 91.Fl H , 92.Fl L , 93and 94.Fl P 95options are ignored unless the 96.Fl R 97option is specified; 98if none of them are given, 99the default is to not follow symbolic links. 100In addition, these options override each other and the 101command's actions are determined by the last one specified. 102.Pp 103The 104.Ar owner 105and 106.Ar group 107operands are both optional; however, one must be specified. 108If the 109.Ar group 110operand is specified, it must be preceded by a colon 111.Pq Sq \&: 112character. 113.Pp 114The 115.Ar owner 116may be either a numeric user ID or a user name. 117If a user name is also a numeric user ID, the operand is used as a 118user name. 119The 120.Ar group 121may be either a numeric group ID or a group name. 122If a group name is also a numeric group ID, the operand is used as a 123group name. 124.Pp 125By default, 126.Nm 127clears the set-user-ID and set-group-ID bits on the file 128to prevent accidental or mischievous creation of 129set-user-ID and set-group-ID programs. 130This behaviour can be overridden by setting the 131.Xr sysctl 8 132variable 133.Va fs.posix.setuid 134to zero. 135.Pp 136Only the superuser is permitted to change the owner of a file. 137.Sh EXIT STATUS 138.Ex -std chown 139.Sh SEE ALSO 140.Xr chgrp 1 , 141.Xr find 1 , 142.Xr chown 2 , 143.Xr fts 3 , 144.Xr symlink 7 145.Sh STANDARDS 146The 147.Nm 148utility is compliant with the 149.St -p1003.1-2008 150specification. 151.Pp 152The ability to specify 153.Ar group 154without 155.Ar owner 156is an extension to that specification. 157.Pp 158Some 159.Pf non- Bx 160systems may allow the (non-privileged) owner of a file to change 161its ownership. 162.Pp 163Previous versions of the 164.Nm 165utility used the dot 166.Pq Sq \&. 167character to distinguish the group name. 168This has been changed to be a colon 169.Pq Sq \&: 170character so that user and 171group names may contain the dot character. 172