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)