Chown

chown Command Reference

The chown command is used to change the ownership of files or directories. You can specify the new owner, group, or both, and also use a reference file for the change. It is especially useful for adjusting ownership when managing file permissions and security.

Syntax

chown [options]... NewOwner File...
chown [options]... :Group File...
chown [options]... --reference=RFILE File...

• NewOwner: Specifies the new owner and/or group. It can be:
  • OWNER: Just the username or numeric user ID.
  • OWNER.GROUP or OWNER:GROUP: Both the owner and the group are changed.
  • OWNER. or OWNER:: Only the owner is changed, and the group is set to the owner's login group.
  • .GROUP or :GROUP: Only the group is changed.

Options

• -c, --changes: Verbosely describe the action for each file whose ownership changes.

  sudo chown -c Ursula /Users/Shared/MyFile.txt

• --dereference: Operate on the files the symbolic links point to, not the links themselves.

  sudo chown --dereference Ursula /path/to/symlink

• -f, --silent, --quiet: Suppress error messages for files whose ownership cannot be changed.

  sudo chown -f Ursula /path/to/file

• -h, --no-dereference: Act on symbolic links themselves (default behavior).

  sudo chown -h Ursula /path/to/symlink

• --reference=FILE: Use the user and group of a reference file instead of specifying NewOwner.

  sudo chown --reference=/path/to/referencefile /path/to/file

• -R, --recursive: Recursively change ownership of directories and their contents.

  sudo chown -R Ursula /Users/Shared/tmp/

• -v, --verbose: Verbosely describe the action or non-action taken for each file.

  sudo chown -v Ursula /Users/Shared/MyFile.txt

Examples

• Change the owner of a file:

  sudo chown Ursula /Users/Shared/MyFile.txt

• Recursively change ownership of everything in a directory:

  sudo chown -R Ursula:staff /Users/Shared/tmp/

• Change ownership of only hidden files in a directory: To avoid issues with symbolic links, use this command:

  sudo chown -R audrey /Work/.[^.]*