get current URL

function.php

<?php
// get current URL
function get_current_URL() {
  $current_url  = 'http';
  $server_https = $_SERVER["HTTPS"];
  $server_name  = $_SERVER["SERVER_NAME"];
  $server_port  = $_SERVER["SERVER_PORT"];
  $request_uri  = $_SERVER["REQUEST_URI"];
  if ($server_https == "on") $current_url .= "s";
  $current_url .= "://";
  if ($server_port != "80") $current_url .= $server_name . ":" . $server_port . $request_uri;
  else $current_url .= $server_name . $request_uri;
  return $current_url;
}