title: Is it possible to identify the length / size of a readable stream?
body: <p>I'm trying to resize a file in node using gm.js and use the <code>.stream()</code> to create a readable stream of the resized image. Now I want to upload it using knox.js <code>.putStream()</code> but <code>Content-Length</code> is a required header. Is it possible to identify the size of the readable stream so I can use it in the <code>Content-Length</code> header?</p>
  
  <p>Thanks in advance guys.</p>