function to get the current URL

get_current_url.php

<?php
function get_current_url ( $include_request_uri = true ) {
	$https = isset( $_SERVER[ "HTTPS" ] ) && strtolower( $_SERVER[ "HTTPS" ] ) === "on"; 
	$protocol = 'http' . ( $https ? 's' : '' ) . '://';
	$host = $_SERVER[ "SERVER_NAME" ];
	$port = $_SERVER[ "SERVER_PORT" ];
	$request = $include_request_uri ? get_request_uri() : '';
	return $protocol . $host . ( $port != 80 ? ":$port" : '' ) . $request;
}

function get_request_uri () {
	$request_uri_supported = isset( $_SERVER[ "REQUEST_URI" ] ); // IIS
	$request = $request_uri_supported ? $_SERVER[ "REQUEST_URI" ] : $_SERVER[ "PHP_SELF" ];
	$request = htmlspecialchars( $request ); // XSS
	if ( !$request_uri_supported and count( $_GET ) ) {
		$request .= '?' . http_build_query( $_GET );
	}
	return $request;
}