Nginx Config Location Regex With Language Code In

问题:

Trying to achieve constant language code in url's 1st segment with nginx regex location configuration and could not find the correct syntax.

Necessary result:

• example.com stays example.com
• example.com/en stays example.com/en
• example.com/en/ stays example.com/en or example.com/en/ (don't care)
• example.com/en/etc stays example.com/en/etc
  
  
• example.com/etc changes to example.com/en/etc

• example.com/etc/segment changes to example.com/en/etc/segment
  
  
  
  Currently I have found out this code but it still stuck in somewhere. It makes permanent loop and doesn't not use $1 argument.

  location ~ "^/(?![a-z]{2}/)(.+)$" {
      rewrite / /en/$1 permanent;
  }
  
  #Using handler here for removing index.php in uri (example.com/index.php -> example.com);
  location / {
      index index.htm index.html index.php;
      try_files $uri $uri/ @handler;
  }
  
  location @handler {
      rewrite / /index.php?$query_string;
  }
  

UPDATE: Answer can be found in this question: https://stackoverflow.com/a/33913261/2662849