execute (Debugger::SourceCommand)

    # File cli/ruby-debug/commands/source.rb, line 10
        def execute
          file = File.expand_path(@match[1]).strip
          unless File.exist?(file)
            errmsg "Command file '#{file}' is not found\n"
            return
          end
          if @state and @state.interface
            @state.interface.command_queue += File.open(file).readlines
          else
            Debugger.run_script(file, @state)
          end
        end