nginx 301转发双反斜杠

nginx 301转发双反斜杠
网上说是这样写就好

rewrite ^/(.*)$ http://www.baidu.com/$1 permanent;

但是仍然没什么效果，试了很多方法，后来干脆写死，加一段

rewrite ^/$ http://www.baidu.com permanent;

server {
    listen 81;
    server_name baidu.com;
    auth_basic off;
    rewrite ^/$ http://www.baidu.com permanent;
    rewrite ^/(.*)$ http://www.baidu.com/$1 permanent;

}