title: Bash: Tab filename completion on all sub-folders
body: <p>Is there any way to configure bash so that hitting tab to expand filename will search all sub-folders as well as the current folder?</p>
  
  <p>e.g. my folder structure</p>
  
  <pre><code>readme.txt
  colors/blue.txt
  colors/red.txt
  people/roger.txt
  </code></pre>
  
  <p>I want <code>less r&lt;tab&gt;</code> (or maybe <code>less **/r&lt;tab&gt;</code> to expand to show all expansion options beginning with <code>r</code>:</p>
  
  <p><code>readme.txt colors/red.txt people/roger.txt</code></p>