title: how to log the file requested via express.static
body: <p>here is my code </p>
  
  <pre><code>var express=require("express");
  var app=express();
  var port=8181;
  app.use(express.static(__dirname));
  app.listen(port);
  </code></pre>
  
  <p>it is serving static file  properly</p>
  
  <p>I want to log when a  file with an extension .xls is being requested </p>
  
  <p>how can i achieve it ?</p>