Ruby open-uri重定向被禁止

Question

我有这个简单的html解析器(用于学习目的),我一直在研究:

require 'open-uri'
puts "Enter URL to parse HTML: "
url = gets.chomp
puts "Enter tag to parse from: "
tag = gets.chomp
response = open(url).read
title1 = response.index(tag)
title2 = response.index(tag.insert(1,'/')) -1
result = response[(title1 + tag.length - 1)..title2]
print result 

当我输入时http://twitter.com,我收到此错误消息:

ERROR: `open_loop': redirection forbidden: http://twitter.com -> https://twitter.com/ (RuntimeError)
from /usr/local/rvm/rubies/ruby-2.1.4/lib/ruby/2.1.0/open-uri.rb:149:in `open_uri'
from /usr/local/rvm/rubies/ruby-2.1.4/lib/ruby/2.1.0/open-uri.rb:704:in `open'
from /usr/local/rvm/rubies/ruby-2.1.4/lib/ruby/2.1.0/open-uri.rb:34:in `open'
from /home/ubuntu/workspace/htmlparse.rb:6:in `<main>' 

有任何建议或帮助吗？我是Ruby新手,我知道其他html解析模块,但我这样做是为了学习Ruby基础知识.谢谢.

Answer 1

看看open_uri_redirections gem.

它修补了Ruby的OpenURI,允许从HTTP到HTTPS的重定向或其他方式.

Answer 2

您还可以捕获异常,然后使用"https"网址再次尝试.

url = "http://classic.ona.io/api/v1/files/3538545?filename=gringgo/attachments/1485229166168.jpg"

uri = URI.parse(url)
tries = 3

begin
  uri.open(redirect: false)
rescue OpenURI::HTTPRedirect => redirect
  uri = redirect.uri # assigned from the "Location" response header
  retry if (tries -= 1) > 0
  raise
end

资料来源:https://twin.github.io/improving-open-uri/

Answer 3

Ruby 2.4 修复了升级重定向（从 http -> https）open-uri，现在：

RUBY_VERSION
=> "2.4.2"

require 'open-uri'
=> true

open('http://twitter.com')
=> #<Tempfile:/tmp/open-uri20170926-24254-1kflwxq>

来源：http : //blog.bigbinary.com/2017/03/02/open-uri-in-ruby-2-4-allows-http-to-https-redirection.html