Nginx Rewrite规则初探

   if ($http_user_agent ~MSIE){
   rewrite ^(.*)$/msie/$1 break;
    }

   if (!-f$request_filename){
     rewrite ^/img/(.*)$/site/$host/images/$1 last;
     }

         location ~ .*\.(sh|bash)?$
          {
           return 403;
                }     

      rewrite指令的最后一项参数为flag标记，支持的flag标记主要有以下几种：
      last ：相当于Apache里德(L)标记，表示完成rewrite；
      break；本条规则匹配完成后，终止匹配，不再匹配后面的规则
      redirect：返回302临时重定向，浏览器地址会显示跳转后的URL地址
      permanent：返回301永久重定向，浏览器地址栏会显示跳转后的URL地址
      last和break用来实现URL重写，浏览器地址栏URL地址不变

       location /b   {
           autoindex  on;
          alias /usr/local/nginx/html/redhat;       
          rewrite ^/b/?$ /bbs permanent;

          }
         location /bbs {
            autoindex on;
         alias /usr/local/nginx/html/bbs;
         }

rewrite ^/b/?$ /bbs permannet;

        if ($http_user_agent ~ Firefox) {
          rewrite ^(.*)$ /firefox/$1 break;
          }
 
          if ($http_user_agent ~ MSIE) {
            rewrite ^(.*)$ /msie/$1 break;
           }

         if ($http_user_agent ~ Chrome) {
              rewrite ^(.*)$ /chrome/$1 break;
         } 

         location ~*\.(gif|jpg|png|swf|flv)${
         valid_referers none blocked www.cheng.com*.test.com;
         if ($invalid_referer)
          rewrite ^/(.*) http://www.cheng.com/error.html         
           }

server {
         listen       80;
         server_name  cheng.example.com;
         write ^(.*)$  http://zhang.example.com/$1 permanent;
         location / {
             root   html;
             index  index.html index.htm;
         }