CHOWN(8) | System Manager's Manual | CHOWN(8)

# NAME

`chown` — change file owner and group

# SYNOPSIS

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

`chown` | [`-R` [`-H` | `-L` | `-P`]] [`-dfhv`] :group file ...

`chown` | [`-R` [`-H` | `-L` | `-P`]] [`-dfhv`] `--reference=rfile` file ...

# DESCRIPTION

`chown` sets 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. (Symbolic links encountered in the tree 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.
`-R`
  Change the user ID and/or the group ID for the file hierarchies rooted in the files instead of just the files themselves.
`-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.
`-f`
  Do not report any failure to change file owner or group, nor modify the exit status to reflect such failures.
`-h`
  If file is a symbolic link, the owner and/or group of the link is changed.
`-v`
  Cause `chown` to be verbose, showing files as they are processed.

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 default is as if the `-P` option had been specified.

The `-L` option cannot be used together with the `-h` option.

The owner and group operands are both optional, however, one must be specified; alternatively, both the owner and group may be specified using a reference rfile specified using the `--reference` argument. If the group operand is specified, it must be preceded by a colon (``:'') character.

The owner may be either a user name or a numeric user ID. The 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.

The ownership of a file may only be altered by a super-user for obvious security reasons.

Unless invoked by the super-user, `chown` 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.

# EXIT STATUS

The `chown` utility exits 0 on success, and >0 if an error occurs.

# COMPATIBILITY

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.

# SEE ALSO

chflags(1), chgrp(1), find(1), chown(2), lchown(2), fts(3), symlink(7)

# STANDARDS

The `chown` command is expected to be POSIX 1003.2 compliant.

The `-v` and `-d` options and the use of ``#'' to force a numeric lookup are extensions to IEEE Std 1003.2 (“POSIX.2”).

# HISTORY

A `chown` utility appeared in Version 1 AT&T UNIX.

May 19, 2023 | NetBSD 11.99