apache - I am trying to block a kind browser with RewriteCond %{HTTP_USER_AGENT} -

This browser recognizes the Apache log

"Mozilla / 5.0 (Windows NT 6.1; RV: 31.0 Gecko / 20100101 Firefox / 31.0 "

What should be the correct syntax?

Rewindcore% {HTTP_USER_AGENT} "Mozilla / 5.0 (Windows NT 6.1; RV: 31.0) Do not match exact on user agent because it may be slightly different and the test is the same browser Version will be unsuccessful. To exclude Firefox version 31, simply log on to the substring

  revised code on the revised version% {HTTP_USER_AGENT} \ Firefox / 31 [NC] ^ - [F, L]  

Now, the browser receives 403 forbidden error You can.