module Rfc2047

from blade.nagaokaut.ac.jp/cgi-bin/scat.rb/ruby/ruby-talk/69323 via dev.joyent.com/projects/connector/browse/trunk/vendor/rfc2047.rb

An implementation of RFC 2047 decoding.

This module depends on the iconv library by Nobuyoshi Nakada, which I’ve heard may be distributed as a standard part of Ruby 1.8.

This file is distributed under the same terms as Ruby.

Constants

ADJACENT_WORDS: Look for two adjacent words in the same encoding.

Public Class Methods

decode(from, target='utf-8') click to toggle source

Decodes a string, from, containing RFC 2047 encoded words into a target character set, target defaulting to utf-8. See iconv_open(3) for information on the supported target encodings. If one of the encoded words cannot be converted to the target encoding, it is left in its encoded form.

# File lib/rfc2047.rb, line 24
def self.decode(from, target='utf-8')
  from.gsub(ADJACENT_WORDS, "\\1").gsub(WORD) do |word|
    cs = $1
    encoding = $2
    text = $3
    # B64 or QP decode, as necessary:
    case encoding.downcase
    when 'b'
      text = text.unpack('m*')[0]
    when 'q'
      # RFC 2047 has a variant of quoted printable where a ' ' character
      # can be represented as an '_', rather than =32, so convert
      # any of these that we find before doing the QP decoding.
      text = text.tr("_", " ")
      text = text.unpack('M*')[0]
    else
      raise Unparseable, from
    end
    # Convert
    #
    # Remember: Iconv.open(to, from)
    begin
      text = text.encode(target, cs)
    rescue 
      raise Unparseable, from
    end
  end
end