# File cli/ruby-debug/processor.rb, line 220
    def one_cmd(commands, context, input)
      if cmd = lookup(input)
        if context.dead? && cmd.class.need_context
          p cmd
          print "Command is unavailable\n"
        else
          cmd.execute
        end
      else
        unknown_cmd = commands.find{|cmd| cmd.class.unknown }
        if unknown_cmd
            unknown_cmd.execute
        else
          errmsg "Unknown command: \"#{input}\".  Try \"help\".\n"
        end
      end
    end