获取当前URL

从参考：

<?phpfunction curPageURL() {    $pageURL = 'http';    if ($_SERVER["HTTPS"] == "on") {        $pageURL .= "s";    }    $pageURL .= "://";    if ($_SERVER["SERVER_PORT"] != "80") {        $pageURL .= $_SERVER["SERVER_NAME"].":".$_SERVER["SERVER_PORT"].$_SERVER["REQUEST_URI"];    } else {        $pageURL .= $_SERVER["SERVER_NAME"].$_SERVER["REQUEST_URI"];    }    return $pageURL;}?>