解码base64字符串并写入文件。

I'm trying to read file which contains encoded base64 string and write decoded output into another file. My Input.txt contains a base64 string, something like:

我正在尝试读取包含编码的base64字符串的文件，并将解码后的输出写到另一个文件中。我的输入。txt包含一个base64字符串，如下所示:

PD94bWwgdmVyc2lvbj0iMS4wIiBlbmNvZGluZz0iVVRGLTgiPz48cmV2aWV3LWNhc2UgY3JlYXRl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\r\nIG5hbWU9IlBob25lTnVtYmVyIiB2YWx1

This string is created on server side with Java apache codec.binary.Base64 library. This string is captured with Fiddler when two different web services communicates with each other. Sometimes I have no access to the another web-service, that is why I sniff messages between services. In addition I use Ruby to automate some routine tasks and decided this time to use Ruby again. For encoding captured base64 string I use next snippet of code:

这个字符串是在服务器端用Java apache codec.binary创建的。Base64图书馆。当两个不同的web服务彼此通信时，使用Fiddler捕获此字符串。有时我无法访问另一个web服务，这就是为什么我在服务之间嗅探消息。此外，我还使用Ruby实现了一些常规任务的自动化，这次我决定再次使用Ruby。对于捕获的base64字符串的编码，我使用下面的代码片段:

require "base64"

content = File.read('Input.txt')
decode_base64_content = Base64.decode64(content) 
File.open("Output.txt", "wb") do |f|
  f.write(decode_base64_content)
end

But output looks malformed, like <?xml version="1.0" encoding="UTF-8"?><review-case create®vFFSТ#2фЦ"у#B“ЈCЈS"7—7FVУТ%G&f–wW&хFVЧЖFUфЦзnagement_v5.1" ba and so on. Can you please advise on what I'm doing wrong? I use Ruby 1.9.3 on Windows 7 and Ubuntu 12.04.

但是输出看起来是畸形的，比如 <复审案件创建®vffsт# 2фц“bу#”јcјs 7-7fvут% g&f-ww&хfvчжfuфцзnagement_v5.1“ba等等。你能告诉我我做错了什么吗?我在windows 7和ubuntu 12.04上使用ruby 1.9.3。< p>

1 个解决方案

#1

I do not know how you manage to do this, but the line endings \r\n in your string seem to be there as 4-byte character sequences, not as 2-byte escaped CRLF. If I copy your file into a ruby string with single ticks:

我不知道您是如何做到这一点的，但是在您的字符串中，行尾的r\n似乎是4字节字符序列，而不是2字节的转义CRLF。如果我将您的文件复制到一个带有单引号的ruby字符串中:

unescaped='PD94bWwgdmVyc2lvbj0iMS4wIiBlbmNvZGluZz0iVVRGLTgiPz48cmV2aWV3LWNhc2UgY3JlYXRl\r\nZGF0ZT0iMTMvTWFyLzIwMTQgMDk6MDQ6NTEiIHN5c3RlbT0iVHJhZmlndXJhX1RlbXBsYXRlX01h\r\nbmFnZW1lbnRfdjUuMSIgYmF0Y2hpZD0iMCIgdHJhbnNhY3Rpb25ubz0iMSIgYmF0Y2huYW1lPSJH'
Base64.decode64(unescaped)
#=> garbled text for every second line

if I do the same with double quotes (which respect the escape sequences):

如果我对双引号(与转义序列有关)也这样做:

escaped="PD94bWwgdmVyc2lvbj0iMS4wIiBlbmNvZGluZz0iVVRGLTgiPz48cmV2aWV3LWNhc2UgY3JlYXRl\r\nZGF0ZT0iMTMvTWFyLzIwMTQgMDk6MDQ6NTEiIHN5c3RlbT0iVHJhZmlndXJhX1RlbXBsYXRlX01h\r\nbmFnZW1lbnRfdjUuMSIgYmF0Y2hpZD0iMCIgdHJhbnNhY3Rpb25ubz0iMSIgYmF0Y2huYW1lPSJH"
Base64.decode64(escaped)
#=> all is well that ends well

Therefore the problem seems to occur when you write the file. It can be amended in Ruby though:

因此，当您编写文件时，似乎会出现问题。可以在Ruby中修改:

unescaped='PD94bWwgdmVyc2lvbj0iMS4wIiBlbmNvZGluZz0iVVRGLTgiPz48cmV2aWV3LWNhc2UgY3JlYXRl\r\nZGF0ZT0iMTMvTWFyLzIwMTQgMDk6MDQ6NTEiIHN5c3RlbT0iVHJhZmlndXJhX1RlbXBsYXRlX01h\r\nbmFnZW1lbnRfdjUuMSIgYmF0Y2hpZD0iMCIgdHJhbnNhY3Rpb25ubz0iMSIgYmF0Y2huYW1lPSJH'
Base64.decode64(unescaped)
escaped=unescaped.gsub('\\r', "\r").gsub('\\n', "\n")
Base64.decode64(escaped)
#=> now you should be fine again

but of course the correct solution would be to store the file correctly.

当然，正确的解决方案是正确地存储文件。

Given your current file the following should work:

考虑到您当前的文件，以下内容应该是有效的:

require "base64"

content = File.read('Input.txt')
content.gsub!('\\r', "\r")
content.gsub!('\\n', "\n")
decode_base64_content = Base64.decode64(content) 
File.open("Output.txt", "wb") do |f|
  f.write(decode_base64_content)
end

Please do post some output if it does not.

如果不是，请做一些输出。

#1

unescaped='PD94bWwgdmVyc2lvbj0iMS4wIiBlbmNvZGluZz0iVVRGLTgiPz48cmV2aWV3LWNhc2UgY3JlYXRl\r\nZGF0ZT0iMTMvTWFyLzIwMTQgMDk6MDQ6NTEiIHN5c3RlbT0iVHJhZmlndXJhX1RlbXBsYXRlX01h\r\nbmFnZW1lbnRfdjUuMSIgYmF0Y2hpZD0iMCIgdHJhbnNhY3Rpb25ubz0iMSIgYmF0Y2huYW1lPSJH'
Base64.decode64(unescaped)
#=> garbled text for every second line