javascript - URL redirection in php for Opera Mini browser -

i redirect urls opened opera mini browser specific browser using php. have code below not working. please me.

  if(! empty($_server['http_user_agent'])){      $useragent = $_server['http_user_agent'];         if( preg_match('@(opera mini)@', $useragent)){              $host = $_server['request_uri'];              if($host !== 'mywebsite.com/browser-error'){                  header('location: ./browser-error');             }         } }  

according dev.opera.com, opera mini user-agent has following format:

user-agent: opera/9.80 ($platform_name$; $product_name$/$client_version$/ $server_version$;u; $locale$) $presto_version$ $equiv_desktop_version$

example:

user-agent: opera/9.80 (android; opera mini/8.0.1807/36.1609; u; en) presto/2.12.423 version/12.16 

to detect use:

if (strpos($_server['http_user_agent'], 'opera mini') !== false) {     echo 'is opera mini'; }