chown command

chown - change file owner and group

The chown command in Linux is used to change the ownership of files and directories, assigning them to a specific user and/or group. It’s essential for managing access rights and permissions in a multi-user system.

Note: Changing ownership typically requires root privileges (use sudo).

Usage: chown [OPTION]... [OWNER]:[GROUP]] FILE...

• OWNER: The new owner (username or UID).
• GROUP: The new group (group name or GID, optional).
• FILE: The target file(s) or directory(s).
• OPTION: Flags to modify behavior (e.g., -R for recursive).

Common Options Summary

Option	Description
-R	Recursive (apply to directory contents)
-v	Verbose output
--reference	Copy ownership from another file
-c	Report changes only (like -v but quieter)

Examples

• Basic Usage

  Change the owner of a file to a specific user.

  sudo chown alice file.txt
  • Sets alice as the owner of file.txt.
  • Check with:

    ls -l file.txt
    • Output (example): -rw-r--r-- 1 alice users 0 Apr 1 10:00 file.txt.

• Changing Group Ownership

  Specify a group with a colon (:) after the user.

  sudo chown alice:developers file.txt
  • Sets owner to alice and group to developers.

  Group Only:

  Use a colon before the group to change only the group:

  sudo chown :developers file.txt
  • Keeps the current owner but sets the group to developers.

• Recursive Changes

  Use -R to change ownership of a directory and its contents.

  sudo chown -R alice:developers /var/www
  • Sets alice as owner and developers as group for /var/www and everything inside.

• Using Numeric IDs

  Specify user ID (UID) and group ID (GID) instead of names.

  sudo chown 1000:1001 file.txt
  • Sets UID 1000 and GID 1001 (find with id username).

• Verbose Output

  Use -v to see what changes are made.

  sudo chown -v alice file.txt
  • Output: changed ownership of 'file.txt' from bob to alice.

• Copying Ownership

  Use --reference to copy ownership from another file.

  sudo chown --reference=template.txt file.txt
  • Sets file.txt’s owner and group to match template.txt.

To get help related to the chown command use --help option

$ chown --help
Usage: chown [OPTION]... [OWNER][:[GROUP]] FILE...
  or:  chown [OPTION]... --reference=RFILE FILE...
Change the owner and/or group of each FILE to OWNER and/or GROUP.
With --reference, change the owner and group of each FILE to those of RFILE.

  -c, --changes          like verbose but report only when a change is made
  -f, --silent, --quiet  suppress most error messages
  -v, --verbose          output a diagnostic for every file processed
      --dereference      affect the referent of each symbolic link (this is
                         the default), rather than the symbolic link itself
  -h, --no-dereference   affect symbolic links instead of any referenced file
                         (useful only on systems that can change the
                         ownership of a symlink)
      --from=CURRENT_OWNER:CURRENT_GROUP
                         change the owner and/or group of each file only if
                         its current owner and/or group match those specified
                         here.  Either may be omitted, in which case a match
                         is not required for the omitted attribute
      --no-preserve-root  do not treat '/' specially (the default)
      --preserve-root    fail to operate recursively on '/'
      --reference=RFILE  use RFILE's owner and group rather than
                         specifying OWNER:GROUP values
  -R, --recursive        operate on files and directories recursively

The following options modify how a hierarchy is traversed when the -R
option is also specified.  If more than one is specified, only the final
one takes effect.

  -H                     if a command line argument is a symbolic link
                         to a directory, traverse it
  -L                     traverse every symbolic link to a directory
                         encountered
  -P                     do not traverse any symbolic links (default)

      --help     display this help and exit
      --version  output version information and exit

Owner is unchanged if missing.  Group is unchanged if missing, but changed
to login group if implied by a ':' following a symbolic OWNER.
OWNER and GROUP may be numeric as well as symbolic.

Examples:
  chown root /u        Change the owner of /u to "root".
  chown root:staff /u  Likewise, but also change its group to "staff".
  chown -hR root /u    Change the owner of /u and subfiles to "root".

For more details, check the manual with man chown