Ruby Mail for ISO-2022-JP / SHIFT_JIS

gistfile1.txt

require 'rubygems'
gem 'mail', '=2.2.19'

require 'mail'
require 'nkf'

module Mail
  module Encodings
    class SevenBit
      def self.decode(str)
        NkfShell.to_jis(super, '-j')
      end
    end

    class EightBit
      def self.decode(str)
        NkfShell.to_jis(str, '-s').to_lf
      end
    end
  end
end

module Mail
  class SubjectField
    def wrapped_value # :nodoc:
      if %w(ISO-2022-JP SHIFT-JIS).include? charset.upcase
        "Subject: #{NkfShell.to_subject_jis(value, charset.upcase)}"
      else
        super
      end
    end
  end
end

module Mail
  class Ruby18
    def Ruby18.b_value_encode(str, encoding)
      # Ruby 1.8 requires an encoding to work
      raise ArgumentError, "Must supply an encoding" if encoding.nil?
      encoding = encoding.to_s.upcase.gsub('_', '-')

      if encoding.upcase == "ISO-2022-JP"
        str = NkfShell.to_base64_jis(str, "-MBj")
      elsif encoding.upcase == "SHIFT-JIS"
        str = NkfShell.to_base64_jis(str, "-MBs")
      else
        str = Encodings::Base64.encode(str)
      end

      [str, encoding]
    end
  end

  class Ruby19
    def Ruby19.b_value_encode(str, encoding)
      encoding = str.encoding.to_s

      if encoding.upcase == "ISO-2022-JP"
        str = NKF.nkf('-MBj', str)
      elsif encoding.upcase == "SHIFT-JIS"
        str = NKF.nkf('-MBs', str)
      else
        str = Ruby19.encode_base64(str)
      end

      [str, encoding]
    end
  end
end

class NkfShell
  def self.to_base64_jis(str,opt)
    to_jis(str, opt)
  end

  def self.to_subject_jis(str, encoding)
    if encoding == "ISO-2022-JP"
      "=?ISO-2022-JP?B?#{Base64.encode64(to_jis(str,"-j")).delete("\r\n")}?="
    elsif encoding == "SHIFT-JIS"
      "=?SHIFT-JIS?B?#{Base64.encode64(to_jis(str,"-s")).delete("\r\n")}?="
    end
  end

  def self.to_jis(str, argument="-j")
    `bash -c "type /usr/local/bin/nkf" 2> /dev/null`

    if $?.success?
      IO.popen("/usr/local/bin/nkf #{argument}", "r+:utf-8:utf-8") do |nkf|
        nkf.puts(str)
        nkf.close_write()
        nkf.read().to_s.chomp
      end
    else
      puts "no `nkf` installed to /usr/local/bin/nkf"
      NKF.nkf(argument, str)
    end
  end
end