title: Delete a file after download it using nodejs
body: <p>I'm using Node.js and I need to delete a file after user download it. Is there any way to call a callback method after pipe process ends, or any event for that purpose? </p>
  
  <pre><code>exports.downloadZipFile = function(req, res){
      var fileName = req.params['fileName'];
      res.attachment(fileName);
      fs.createReadStream(fileName).pipe(res); 
  
      //delete file after download             
  };
  </code></pre>