在Ruby中下载二进制文件

Question

我可以下载我的文件，但我最终得到的文件说它无法在我的Windows版本上执行。这是我的代码：

  Net::HTTP.start(url_base) do |http|
    if response.code == '200'

      self.size = response['content-length'].to_i

      local_file = save_dir + File::SEPARATOR + strip_file_name(url_path)

      if !application_exists?(local_file, response['content-length'].to_i) || overwrite_file?
        build_display
        self.progress_bar = ProgressBar.new(response['content-length'].to_i, PROGRESSBAR_SIZE_WIDTH)

        File.open(local_file, 'w') { |f|
          http.get(URI.escape(url_path)) do |str|
            f.write str
            @counter += str.length
            @window.setpos(PROGRESSBAR_LOCATION_TOP, 1)
            @window << (self.progress_bar.show(@counter)).center(WINDOW_WIDTH - 2)
            @window.refresh

            char = @window.getch
            http.finish if char == 'c' # cancel download
          end
        }
      end

    end
  end

如果我使用open-uri下载：

       file = open(url,
         :content_length_proc => lambda { |content_length|
           if content_length && 0 < content_length
             self.progress_bar = ProgressBar.new(content_length, PROGRESSBAR_SIZE_WIDTH)
           end
         },
         :progress_proc       => lambda { |size|
           #@counter += str.length
           @window.setpos(PROGRESSBAR_LOCATION_TOP, 1)
           @window << (self.progress_bar.show(size)).center(WINDOW_WIDTH - 2)
           @window.refresh

           char = @window.getch
           f.close if char == 'c' # cancel download
         },
         :read_timeout        => 10)
    FileUtils::cp(file, local_file)

一切正常......问题是，我需要能够取消下游中流。我怎么能a）以'单块'的方式使用net :: http下载，我认为open-uri可以，或者b）使用open-uri取消下载中流？