http协议的基本介绍，实例笔记 if(isset($_SERVER['HTTP_REFERER'])) { //取出$SERVER['HTTP_REFERER'] //判断 isset($SERVER['HTTP_REFERER'] 是不是以，本网站域名开始（http://localhost/Myphp/http/开始） if(strpos($_SERVER['HTTP_REFERER'],"http://localhost/Myphp/http/")==0) { echo "密码是qqqqqqqqqqqqqq"; } else { //跳转