# File lib/guard/notifiers/growl.rb, line 47
      def available?(silent = false)
        if RbConfig::CONFIG['host_os'] =~ /darwin/
          require 'growl'

          if ::Growl.installed?
            true
          else
            ::Guard::UI.error "Please install the 'growlnotify' executable." unless silent
            false
          end

        else
          ::Guard::UI.error 'The :growl notifier runs only on Mac OS X.' unless silent
          false
        end

      rescue LoadError, NameError
        ::Guard::UI.error "Please add \"gem 'growl'\" to your Gemfile and run Guard with \"bundle exec\"." unless silent
        false
      end