Regex routers in zend framework,how to make merge these routers?

Question

Hi there, I need to know how can I merge these routers into one? I want to have just one router instead of these ones. I appreciate any answer.:)

        $route = new Zend_Controller_Router_Route_Regex(
  '([a-z]{2})/(\w+)/(\w+)/(\w+)',
  array('controller'=>'index',
     'action' => 'index',
   'module'=>'default',
   'lang'=>$lang
  ),
  array(
   1=>'lang',
   2=>'module',
   3=>'controller',
   4=>'action'
  )
 );
 $router->addRoute('default_lang_action', $route);

 $route = new Zend_Controller_Router_Route_Regex(
  '([a-z]{2})/(\w+)/(\w+)',
  array('controller'=>'index',
     'action' => 'index',
   'module'=>'login',
   'lang'=>$lang
  ),
  array(
   1=>'lang',
   2=>'module',
   3=>'controller'
        )
 );
 $router->addRoute('default_lang_con', $route);

 $route = new Zend_Controller_Router_Route_Regex(
  '([a-z]{2})/(\w+)',
  array('controller'=>'index',
     'action' => 'index',
   'module'=>'default',
   'lang'=>$lang
  ),
  array(
   1=>'lang',
   2=>'module'
  )
 );
 $router->addRoute('default_lang_mod', $route);

 $route = new Zend_Controller_Router_Route_Regex(
  '([a-z]{2})',
  array('controller'=>'index',
     'action' => 'index',
   'module'=>'default',
   'lang'=>$lang
  ),
  array(
   1=>'lang'
  )
 );
            $router->addRoute('default_lang', $route);

Answer 1

So instead of the four routes you have now, you want one route in which the last three parameters are optional? Try this regex:

'([a-z]{2})(?:/(\w+)(?:/(\w+)(?:/(\w+))?)?)?'