chown
— change
file owner and group
chown |
[-fhvx ] [-R
[-H | -L |
-P ]]
owner[:group]
file ... |
chown |
[-fhvx ] [-R
[-H | -L |
-P ]] :group
file ... |
The chown
utility changes the user ID
and/or the group ID of the specified files. Symbolic links named by
arguments are silently left unchanged unless -h
is
used.
The options are as follows:
-H
- If the
-R
option is specified, symbolic links on
the command line are followed and hence unaffected by the command.
(Symbolic links encountered during traversal are not followed.)
-L
- If the
-R
option is specified, all symbolic links
are followed.
-P
- If the
-R
option is specified, no symbolic links
are followed. This is the default.
-R
- Change the user ID and/or the group ID of the file hierarchies rooted in
the files, instead of just the files themselves. Beware of unintentionally
matching the “..” hard link to the
parent directory when using wildcards like
“
.*
”.
-f
- Do not report any failure to change file owner or group, nor modify the
exit status to reflect such failures.
-h
- If the file is a symbolic link, change the user ID and/or the group ID of
the link itself.
-v
- Cause
chown
to be verbose, showing files as the
owner is modified. If the -v
flag is specified
more than once, chown
will print the filename,
followed by the old and new numeric user/group ID.
-x
- File system mount points are not traversed.
The -H
, -L
and
-P
options are ignored unless the
-R
option is specified. In addition, these options
override each other and the command's actions are determined by the last one
specified.
The owner and group
operands are both optional, however, one must be specified. If the
group operand is specified, it must be preceded by a
colon (``:'') character.
The owner may be either a numeric user ID or
a user name. If a user name is also a numeric user ID, the operand is used
as a user name. The group may be either a numeric
group ID or a group name. If a group name is also a numeric group ID, the
operand is used as a group name.
The ownership of a file may only be altered by a super-user for
obvious security reasons.
If chown
receives a
SIGINFO
signal (see the
status
argument for
stty(1)),
then the current filename as well as the old and new file owner and group
are displayed.
The chown
utility exits 0 on
success, and >0 if an error occurs.
Previous versions of the chown
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.
On previous versions of this system, symbolic links did not have
owners.
The -v
and -x
options are non-standard and their use in scripts is not recommended.
The chown
utility is expected to be
IEEE Std 1003.2 (“POSIX.2”)
compliant.
A chown
utility appeared in
Version 1 AT&T UNIX.