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

  list[0], list[1] Ĥκǽѹ (mtime) ȥ (atime) 
  ޤlist[n] ¸ߤʤ϶Υեޤ

    FileUtils.touch 'timestamp'
    FileUtils.touch Dir.glob('*.c');  system 'make'

