Why is the difference between the ci url, the channel file, and the port file?

Why is the difference between the ci url, the entry file, and the port file? At the end of this post, the url of aa.baidu.ddindex.phpfdsafdeeedexdex1.html aa. baidu. ddindex. phpj ci is edited from q309056448 to 2015-11-1000:32:06. what is the difference between the Portal file?

This post was last edited by q309056448 at 00:32:06

Http://aa.baidu.dd/index.php/fdsafdeeee/index/1.html
Http://aa.baidu.dd/index.php/joifdafdfdsan/index/1.html
Http://aa.baidu.dd/index.php/feppppoin/indefdasfdax/1.html
No matter what you write, you can run to the default home controller, even if the controller behind index. php does not exist.
But as long as index. php is removed, there will be no problem. why?
The following is the virtual machine configuration in nginx:

server {
        listen       80;
        server_name  aa.baidu.dd;
index index.php;
client_max_body_size 5M;
client_body_buffer_size 128k;

        charset utf-8;
        location / {
            root   /var/www/baidu/wx;
            index  index.php;
if (!-e $request_filename)
{
rewrite  ^/(.*)$  /index.php/$1  last;
break;
}
        }
        error_page  404              /404.html;
        error_page   500 502 503 504  /50x.html;
        location = /50x.html {
            root   html;
        }

location ~ .+\.php($|/){
set $script    $uri;
set $path_info  "/";
if ($uri ~ "^(.+\.php)(/.+)")
{
set $script     $1;
set $path_info  $2;
}
            fastcgi_pass   127.0.0.1:9000;
            fastcgi_index  index.php;
            fastcgi_param  SCRIPT_FILENAME  /var/www/baidu/wx$fastcgi_script_name;
            include        fastcgi_params;
        }
    }

------ Solution ----------------------
Rewrite ^/(. *) $/index. php/$1 last;