How to Get the Current Page URL in PHP

How to Get the Current Page URL in PHP

 $CurrentURL = 'http';
 if ($_SERVER["HTTPS"] == "on") {$CurrentURL .= "s";}
 $CurrentURL .= "://";
 if ($_SERVER["SERVER_PORT"] != "80") {
  $CurrentURL .= $_SERVER["SERVER_NAME"].":".$_SERVER["SERVER_PORT"].$_SERVER["REQUEST_URI"];
 } else {
  $CurrentURL .= $_SERVER["SERVER_NAME"].$_SERVER["REQUEST_URI"];
 }

 echo $CurrentURL;