--- FileUtils.chmod( mode, list, *options )
  Options: noop verbose

  ե LIST[0]LIST[1] ĤΥѡߥå mode Ѥޤ

    FileUtils.chmod 0644, 'my.rb', 'your.rb'
    FileUtils.chmod 0755, 'somecommand'
    FileUtils.chmod 0755, '/usr/bin/ruby', :verbose

