在下载和计算已经下载的数量之前获取文件大小(http + ruby​​)

Question

任何人都可以帮助我

• 在开始下载之前获取文件大小
• 显示已下载了多少%

.

require 'net/http'
require 'uri'

url = "http://www.onalllevels.com/2009-12-02TheYangShow_Squidoo_Part 1.flv"

url_base = url.split('/')[2]
url_path = '/'+url.split('/')[3..-1].join('/')

Net::HTTP.start(url_base) do |http|
  resp = http.get(URI.escape(url_path))
  open("test.file", "wb") do |file|
    file.write(resp.body)
  end
end
puts "Done."

Answer 1

使用request_head方法.像这样

response = http.request_head('http://www.example.com/remote-file.ext')
file_size = response['content-length']

file_size将以字节为单位.

请按照以下两个链接获取更多信息.

http://ruby-doc.org/stdlib/libdoc/net/http/rdoc/classes/Net/HTTP.html#M000695

http://curl.haxx.se/mail/archive-2002-07/0070.html

Answer 2

所以即使有进度条我也让它工作......

require 'net/http'
require 'uri'
require 'progressbar'

url = "url with some file"


url_base = url.split('/')[2]
url_path = '/'+url.split('/')[3..-1].join('/')
@counter = 0

Net::HTTP.start(url_base) do |http|
  response = http.request_head(URI.escape(url_path))
  ProgressBar#format_arguments=[:title, :percentage, :bar, :stat_for_file_transfer]
  pbar = ProgressBar.new("file name:", response['content-length'].to_i)
  File.open("test.file", 'w') {|f|
    http.get(URI.escape(url_path)) do |str|
      f.write str
  @counter += str.length 
  pbar.set(@counter)
    end
   }
end
pbar.finish
puts "Done."