def chown_R(user, group, list, options = {})
    fu_check_options options, OPT_TABLE['chown_R']
    list = fu_list(list)
    fu_output_message sprintf('chown -R%s %s%s',
                              (options[:force] ? 'f' : ''),
                              [user,group].compact.join(':') + ' ',
                              list.join(' ')) if options[:verbose]
    return if options[:noop]
    uid = fu_get_uid(user)
    gid = fu_get_gid(group)
    return unless uid or gid
    list.each do |root|
      Entry_.new(root).traverse do |ent|
        begin
          ent.chown uid, gid
        rescue
          raise unless options[:force]
        end
      end
    end
  end
Options: noop verbose force

Changes owner and group on the named files (in +list+)
to the user +user+ and the group +group+ recursively.
+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_R 'www', 'www', '/var/www/htdocs'
FileUtils.chown_R 'cvs', 'cvs', '/var/cvs', :verbose => true