System properties detection in ruby

specmodule.rb

# origin is here: http://stackoverflow.com/questions/11784109/detecting-operating-systems-in-ruby
require 'rbconfig'

module SpecModule
  def self.os
    @os ||= (
      host_os = RbConfig::CONFIG['host_os']
      case host_os
      when /mswin|msys|mingw|cygwin|bccwin|wince|emc/
        :windows
      when /darwin|mac os/
        :macosx
      when /linux/
        :linux
      when /solaris|bsd/
        :unix
      else
        raise Error::WebDriverError, "unknown os: #{host_os.inspect}"
      end ) ; end ; end