title: Identify specific curl multi response
body: <p>I use <code>curl_multi_exec()</code> to request several websites in parallel. Say, <code>URL1</code>, <code>URL2</code>, and <code>URL3</code>. As soon as one of these websites returns a result, I can process it and then wait for the next response.</p>
  
  <p>Now I need to know, based on the response of the request, which URL this result comes from. I cannot simply check the URL from the response as there might be redirections. So what is the best way to identify from which URL (<code>URL1</code>, <code>URL2</code>, or <code>URL3</code>) the response came from? Can the information from <code>curl_multi_info_read()</code> or <code>curl_getinfo()</code> somehow be used for that? Is there a cURL Option that I can set and request for that?</p>
  
  <p>I also tried storing the cURL handlers before requesting the URLs and compare them with <code>curl_multi_info_read($curlMultiHandle)['handle']</code> but as this is a resource, it is not really comparable.</p>
  
  <p>Any ideas?</p>