title: Mongo shell tab completion
body: <p>I was wondering if it's possible to configure the behavior of tab completion in the mongo shell? The two behaviors I've seen are:</p>
  
  <ol>
  <li>The first hit of the tab key completes as far as there's no ambiguity, the second hit shows a list of possible options.</li>
  <li>Pressing the tab key completes the full expression according to the first possible option.</li>
  </ol>
  
  <p>I personally much prefer the first option. I've seen both behaviors on different environments (all with mongo version 2 and up), and can't figure out whether it's configurable or caused by the environment.</p>