change file owner and group
utility changes the user ID and/or
the group ID of the specified files. Symbolic links named by arguments are
silently left unchanged unless
The options are as follows:
- 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
- If the
-R option is specified, all
symbolic links are followed.
- If the
-R option is specified, no
symbolic links are followed. This is the default.
- 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
- Do not report any failure to change file owner or group, nor modify the
exit status to reflect such failures.
- If the file is a symbolic link, change the user ID and/or the group ID of
the link itself.
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.
- File system mount points are not traversed.
options are ignored unless the
option is specified. In addition, these
options override each other and the command's actions are determined by the
last one specified.
operands are both optional, however,
one must be specified. If the group
is specified, it must be preceded by a colon (``:'') character.
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
signal (see the
then the current filename as well as the old and new file owner and group are
utility exits 0 on success,
and >0 if an error occurs.
Previous versions of the
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
On previous versions of this system, symbolic links did not have owners.
options are non-standard and their use
in scripts is not recommended.
utility is expected to be
IEEE Std 1003.2 (“POSIX.2”)
utility appeared in
Version 1 AT&T UNIX