underscore

# File activesupport/lib/active_support/inflector.rb, line 120
  def underscore(camel_cased_word)
    camel_cased_word.to_s.gsub(/::/, '/').gsub(/([A-Z]+)([A-Z][a-z])/,'\1_\2').gsub(/([a-z\d])([A-Z])/,'\1_\2').downcase
  end