def chown(user, group, list, options = {})
    fu_check_options options, OPT_TABLE['chown']
    list = fu_list(list)
    fu_output_message sprintf('chown %s%s',
                              [user,group].compact.join(':') + ' ',
                              list.join(' ')) if options[:verbose]
    return if options[:noop]
    uid = fu_get_uid(user)
    gid = fu_get_gid(group)
    list.each do |path|
      Entry_.new(path).chown uid, gid
    end
  end
Options: noop verbose

Changes owner and group on the named files (in +list+)
to the user +user+ and the group +group+.  +user+ and +group+
may be an ID (Integer/String) or a name (String).
If +user+ or +group+ is nil, this method does not change
the attribute.

FileUtils.chown 'root', 'staff', '/usr/local/bin/ruby'
FileUtils.chown nil, 'bin', Dir.glob('/usr/bin/*'), :verbose => true