title: how to know who has subscribed to my RSS?
body: <p>is there any PHP script or other software that could let me know who has subscribed to my RSS feeds? (<strong>server part or personal-browser/RSS-reader</strong>)</p>
  
  <p>My RSS files are all generated by a PHP script, then I use an <code>.htaccess</code> URL rewrite rule in order to make the file accessible as <code>.xml</code>.</p>
  
  <p>I know some methods like <code>$_SERVER['HTTP_REFERER']</code>, but I have no confidence to write some reliable code by myself. So, I am looking for some stable code which could help me know who has subscribed to my RSS feeds (and store it into MySQL)?</p>