# File lib/chef/knife/core/ui.rb, line 189
      def confirm(question, append_instructions=true)
        return true if config[:yes]

        stdout.print question
        stdout.print "? (Y/N) " if append_instructions
        answer = stdin.readline
        answer.chomp!
        case answer
        when "Y", "y"
          true
        when "N", "n"
          self.msg("You said no, so I'm done here.")
          exit 3
        else
          self.msg("I have no idea what to do with #{answer}")
          self.msg("Just say Y or N, please.")
          confirm(question)
        end
      end