Fix torrent encoding, convert gbk to utf8, for fix file names.

fix_torrent_encoding.rb

#! /usr/bin/env ruby

# this script used to convert gbk encoding torrent to utf8 encoding

require "bencode"

def print_files(data)
  files = data["info"]["files"]
  files.each do |f|
    path = f["path"][0]
    p path
    p path.encoding
    p path.force_encoding(Encoding::UTF_8)
    p path.encoding
  end
end

def fix_str(str)
  str.force_encoding(Encoding::GBK).encode!(Encoding::UTF_8).force_encoding(Encoding::ASCII_8BIT)
end

def fix_coding(data)
  files = data["info"]["files"]
  files.each do |f|
    fix_str(f["path"][0])
  end
  fix_str(data["comment"]) if data.key? "comment"
end

def get_out_file(fn)
  ext = File.extname(fn)
  bn = File.basename(fn, ext)
  bn + "_utf8" + ext
end

fn = ARGV[0]
content = File.open(fn, "rb") { |f| f.read }
data = BEncode.load(content)
fix_coding(data)
File.open(get_out_file(fn), "wb") { |f| f.write(data.bencode) }