CHOWN(1) User Commands CHOWN(1)

NAME

chown - change file ownership

SYNOPSIS

chown [-fhR] owner[:group] file...


chown -s [-fhR] ownersid[:groupsid] file...


chown -R [-f] [-H | -L | -P] owner[:group] file...


chown -s -R [-f] [-H | -L | -P] ownersid[:groupsid] file...

DESCRIPTION

The chown utility sets the user ID of the file named by each file to the
user ID specified by owner, and, optionally, sets the group ID to that
specified by group.


If chown is invoked by other than the super-user, the set-user-ID bit is
cleared.


Only the owner of a file (or the super-user) can change the owner of that
file.


The operating system has a configuration option
{_POSIX_CHOWN_RESTRICTED}, to restrict ownership changes. When this
option is in effect the owner of the file is prevented from changing the
owner ID of the file. Only the super-user can arbitrarily change owner
IDs whether or not this option is in effect. To set this configuration
option, include the following line in /etc/system:

set rstchown = 1


To disable this option, include the following line in /etc/system:

set rstchown = 0


{_POSIX_CHOWN_RESTRICTED} is enabled by default. See system(5) and
fpathconf(2).

OPTIONS

The following options are supported:

-f
Force. Does not report errors.


-h
If the file is a symbolic link, this option changes the owner of
the symbolic link. Without this option, the owner of the file
referenced by the symbolic link is changed.


-H
If the file specified on the command line is a symbolic link
referencing a file of type directory, this option changes the owner
of the directory referenced by the symbolic link and all the files
in the file hierarchy below it. If a symbolic link is encountered
when traversing a file hierarchy, the owner of the target file is
changed, but no recursion takes place.


-L
If the file is a symbolic link, this option changes the owner of
the file referenced by the symbolic link. If the file specified on
the command line, or encountered during the traversal of the file
hierarchy, is a symbolic link referencing a file of type directory,
then this option changes the owner of the directory referenced by
the symbolic link and all files in the file hierarchy below it.


-P
If the file specified on the command line or encountered during the
traversal of a file hierarchy is a symbolic link, this option
changes the owner of the symbolic link. This option does not follow
the symbolic link to any other part of the file hierarchy.


-R
Recursive. chown descends through the directory, and any
subdirectories, setting the specified ownership ID as it proceeds.
When a symbolic link is encountered, the owner of the symbolic link
is changed, unless the -H or -L option is specified. Unless the -H,
-L, or -P option is specified, the -P option is used as the default
mode.


-s
The owner and/or group arguments are Windows SID strings. This
option requires a file system that supports storing SIDs, such as
ZFS.


Specifying more than one of the mutually-exclusive options -H, -L, or -P
is not considered an error. The last option specified determines the
behavior of chown.

OPERANDS

The following operands are supported:

owner[:group]
A user ID and optional group ID to be assigned to file.
The owner portion of this operand must be a user name
from the user database or a numeric user ID. Either
specifies a user ID to be given to each file named by
file. If a numeric owner exists in the user database as
a user name, the user ID number associated with that
user name is used as the user ID. Similarly, if the
group portion of this operand is present, it must be a
group name from the group database or a numeric group
ID. Either specifies a group ID to be given to each
file. If a numeric group operand exists in the group
database as a group name, the group ID number associated
with that group name is used as the group ID.


file
A path name of a file whose user ID is to be modified.

USAGE

See largefile(7) for the description of the behavior of chown when
encountering files greater than or equal to 2 Gbyte ( 2^31 bytes).

EXAMPLES

Example 1: Changing Ownership of All Files in the Hierarchy

The following command changes ownership of all files in the hierarchy,
including symbolic links, but not the targets of the links:


example% chown -R -h owner[:group] file...

ENVIRONMENT VARIABLES

See environ(7) for descriptions of the following environment variables
that affect the execution of chown: LANG, LC_ALL, LC_CTYPE, LC_MESSAGES,
and NLSPATH.

EXIT STATUS

The following exit values are returned:

0
The utility executed successfully and all requested changes were
made.


>0
An error occurred.

FILES

/etc/passwd
System password file

ATTRIBUTES

See attributes(7) for descriptions of the following attributes:


+--------------------+---------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+--------------------+---------------------+
|CSI | Enabled. See NOTES. |
+--------------------+---------------------+
|Interface Stability | Committed |
+--------------------+---------------------+
|Standard | See standards(7). |
+--------------------+---------------------+

SEE ALSO

chgrp(1), chmod(1), ksh93(1), chown(2), fpathconf(2), passwd(5),
system(5), attributes(7), environ(7), largefile(7), standards(7)

NOTES

chown is CSI-enabled except for the owner and group names.


In the past the behavior of /usr/xpg4/bin/chown and /usr/bin/chown
utilities was different. Now they behave the same way.

February 21, 2019 CHOWN(1)