<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="utf-8">
    <title>file_anchor_ping.html</title>
  </head>
  <body onload="document.body.firstElementChild.click()">
    <a href="/">click me</a>
    <script>
      document.body.firstElementChild.ping = window.location.search.slice(1);
    </script>
  </body>
</html>