比如.php的可以伪装成.html,使用rewrite和反向代理后,实际的资源文件名也可能被隐藏,对于python、ruby这些语言开发网站,并没有约定的扩展名,可以用firebug或者chrome的开发者工具来查看网页的Response Headers:
Response Headers
HTTP/1.1 200 OK
Date: Thu, 29 Nov 2012 01:08:16 GMT
Server: Apache/2.2.15 (CentOS)
X-Powered-By: PHP/5.2.17
Connection: close
Transfer-Encoding: chunked
Content-Type: text/html; charset=UTF-8