title: Understanding lucene segments
body: <p>I have these 3 files in a folder and they are all related to an index created by Lucene:</p>
  
  <ul>
  <li>_0.cfs</li>
  <li>segments_2</li>
  <li>segments.gen</li>
  </ul>
  
  <p>What are they all used for, and is it possible to convert any of them to a human-readable format to discern a bit more about how lucene works with its indexes?</p>