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.\"     from: @(#)chown.8	8.3 (Berkeley) 3/31/94
.\"	$NetBSD: chown.8,v 1.14 2023/05/20 00:54:15 pgoyette Exp $
.\"
.Dd May 19, 2023
.Dt CHOWN 8
.Os
.Sh NAME
.Nm chown
.Nd change file owner and group
.Sh SYNOPSIS
.Nm
.Oo
.Fl R
.Op Fl H | Fl L | Fl P
.Oc
.Op Fl dfhv
.Ar owner Ns Op Ar :group
.Ar
.Nm
.Oo
.Fl R
.Op Fl H | Fl L | Fl P
.Oc
.Op Fl dfhv
.Ar :group
.Ar
.Nm
.Oo
.Fl R
.Op Fl H | Fl L | Fl P
.Oc
.Op Fl dfhv
.Fl Fl reference=rfile
.Ar
.Sh DESCRIPTION
.Nm
sets the user ID and/or the group ID of the specified files.
Symbolic links named by arguments are silently left unchanged unless
.Fl h
is used.
.Pp
The options are as follows:
.Bl -tag -width Ds
.It Fl H
If the
.Fl R
option is specified, symbolic links on the command line are followed.
(Symbolic links encountered in the tree traversal are not followed.)
.It Fl L
If the
.Fl R
option is specified, all symbolic links are followed.
.It Fl P
If the
.Fl R
option is specified, no symbolic links are followed.
.It Fl R
Change the user ID and/or the group ID for the file hierarchies rooted
in the files instead of just the files themselves.
.It Fl d
Do not attempt to update a file's owner or group or its set-user-id
and set-group-id bits if they are all already set to the desired values.
.It Fl f
Do not report any failure to change file owner or group, nor modify
the exit status to reflect such failures.
.It Fl h
If
.Ar file
is a symbolic link, the owner and/or group of the link is changed.
.It Fl v
Cause
.Nm
to be verbose, showing files as they are processed.
.El
.Pp
The
.Fl H ,
.Fl L
and
.Fl P
options are ignored unless the
.Fl R
option is specified.
In addition, these options override each other and the
command's actions are determined by the last one specified.
The default is as if the
.Fl P
option had been specified.
.Pp
The
.Fl L
option cannot be used together with the
.Fl h
option.
.Pp
The
.Ar owner
and
.Ar group
operands are both optional, however, one must be specified; alternatively,
both the owner and group may be specified using a reference
.Ar rfile
specified using the
.Fl Fl reference
argument.
If the
.Ar group
operand is specified, it must be preceded by a colon (``:'') character.
.Pp
The
.Ar owner
may be either a user name or a numeric user ID.
The
.Ar group
may be either a group name or a numeric group ID.
Since it is valid to have a user or group name that is numeric (and
does not have the numeric ID that matches its name) the name lookup
is always done first.
Preceding an ID with a ``#'' character will force it to be taken
as a number.
.Pp
The ownership of a file may only be altered by a super-user for
obvious security reasons.
.Pp
Unless invoked by the super-user,
.Nm
clears the set-user-id and set-group-id bits on a file to prevent
accidental or mischievous creation of set-user-id and set-group-id
programs.
.Sh EXIT STATUS
.Ex -std chown
.Sh COMPATIBILITY
Previous versions of the
.Nm
utility used the dot (``.'') character to distinguish the group name.
This has been changed to be a colon (``:'') character so that user and
group names may contain the dot character.
.Sh SEE ALSO
.Xr chflags 1 ,
.Xr chgrp 1 ,
.Xr find 1 ,
.Xr chown 2 ,
.Xr lchown 2 ,
.Xr fts 3 ,
.Xr symlink 7
.Sh STANDARDS
The
.Nm
command is expected to be POSIX 1003.2 compliant.
.Pp
The
.Fl v
and
.Fl d
options and the use of ``#'' to force a numeric lookup
are extensions to
.St -p1003.2 .
.Sh HISTORY
A
.Nm
utility appeared in
.At v1 .