if we are on a subdomain, change links on page that point to the main domain to point to the same path in the subdomain

gistfile1.txt

(function subdomain() {
  var hostParts = location.host.split('.'); 
  if (hostParts.length < 3) {
    return;
  }
  var subdomain = hostParts[0];
  var domain = hostParts.slice(-2).join('.');
      
  var a = document.getElementsByTagName('a'); // grab every link on the page
  var prefix = 'http://'+domain;
  for (var i = 0; i < a.length; i++) {
    var href = a[i].href;
    if(href.indexOf(prefix) == 0) {
      a[i].href = href.replace(domain, location.host);
      console.log(a[i].href);
    }
  }
})();