Voight-Kampff is a Ruby gem to assist in user agent detection. Voight-Kampf can easily tell you if a request is coming from a crawler, spider or bot. This can be especially helpful in analytics such as page hit tracking.
gem install voight_kampff
A YAML file is used to match user agent strings to their types.
If you'd like to use an updated list or make your own customizations, run rake voight_kampff:import_user_agents. This will download a user_agents.yml file into your Rails /config directory.
To use Regular Expression matching, just set string_match: regex in your user_agent entry. The first match will be used so you should probably put your Regular Expression entries toward the bottom of the file.
There are three ways to use Voight-Kampff
-
In your Ruby on Rails controllers:
request.bot? -
Through the
VoightKampffmodule:
VoightKampff.bot? 'your user agent string' -
Through a
VoightKampff::Testinstance:
VoightKampff::Test.new('your user agent string').bot?
All of the above examples accept human?, bot?, browser?, checker?, downloader?, proxy?, crawler? and spam? methods. All of these methods will return true, false, or nil (if it doesn't recognize the user agent).
Q: What's with the name?
A: It's the machine in Blade Runner that is used to test whether someone is a human or a replicant.
Q: My browser isn't being matched
A: The list is being pulled from user-agents.org.
If you'd like to have entries added to the list please create a new issue or send me a pull request. And if you know of a better source for this sort of data, please let me know.