# File lib/base64.rb, line 72
  def decode_b(str)
    str.gsub!(/=\?ISO-2022-JP\?B\?([!->@-~]+)\?=/i) {
      decode64($1)
    }
    str = Kconv::toeuc(str)
    str.gsub!(/=\?SHIFT_JIS\?B\?([!->@-~]+)\?=/i) {
      decode64($1)
    }
    str = Kconv::toeuc(str)
    str.gsub!(/\n/, ' ') 
    str.gsub!(/\0/, '')
    str
  end