execute (Debugger::HelpCommand)

    # File cli/ruby-debug/commands/help.rb, line 11
        def execute
          if @match[1]
            args = @match[1].split
            cmds = @state.commands.select do |cmd|
              [cmd.help_command].flatten.include?(args[0])
            end
          else
            args = @match[1]
            cmds = []
          end
          unless cmds.empty?
            help = cmds.map{ |cmd| cmd.help(args) }.join
            help = help.split("\n").map{|l| l.gsub(/^ +/, '')}
            help.shift if help.first && help.first.empty?
            help.pop if help.last && help.last.empty?
            print help.join("\n")
          else
            if args and args[0]
              errmsg "Undefined command: \"#{args[0]}\".  Try \"help\"."
            else
              print "ruby-debug help v#{Debugger::VERSION}\n" unless
                self.class.settings[:debuggertesting]
              print "Type 'help <command-name>' for help on a specific command\n\n"
              print "Available commands:\n"
              cmds = @state.commands.map{ |cmd| cmd.help_command }
              cmds = cmds.flatten.uniq.sort
              print columnize(cmds, self.class.settings[:width])
            end
          end
          print "\n"
        end