Agent 212 is a small Ruby library to handle HTTP user agent fields.

It splits a user agent field in parts according to the grammar from RFC2616.

It does not try to detect browsers (in the sense of browser sniffing) but if you write some code around it you can use it for this purpose. If this is what you want to do you might want to take a look at https://github.com/kevinelliott/agent_orange .

user_agent = Agent212.parse(user_agent_string)
if cfnetwork = user_agent.products.detect { |p| p.name == "CFNetwork" }
  if cfnetwork.version != 520.4.3
    raise Foo, 'someone set us up the bomb!'
  else
    puts 'bar'
  end
end

For more examples see: parser_spec line 51 and line 72.

http://en.wikipedia.org/wiki/Agent_212