title: Does golangs os.Stat open the file?
body: <p>Does the <code>os.Stat(path string) (os.FileInfo, error)</code> function (try to) open the file which is located at <code>path</code>, or is there any trickery involved so that it doesn't need to?</p>
  
  <p>Also, what is the performance penalty for opening/closing files multiple times (no reads/writes, I know these are slow), instead of doing it just once? Is it Hard-Disk bound? Does it differ between OSs?</p>