execute

# File lib/irb/cmd/fork.rb, line 19
      def execute(&block)
        pid = send ExtendCommand.irb_original_method_name("fork")
        unless pid 
          class<<self
            alias_method :exit, ExtendCommand.irb_original_method_name('exit')
          end
          if iterator?
            begin
              yield
            ensure
              exit
            end
          end
        end
        pid
      end