$protocol = (!empty($_SERVER['HTTPS']) && $_SERVER['HTTPS'] !== 'off' || $_SERVER['SERVER_PORT'] == 443) ? "https://" : "http://";
$url = $protocol.$_SERVER['HTTP_HOST'].$_SERVER['REQUEST_URI'];
前一个页面：
$_SERVER['HTTP_REFERER']
星期五, 07/13/2018 - 14:50 — 杨超
