Module: Rfc2047

Defined in:
lib/rfc2047.rb

Overview

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.

Copyright © Sam Roberts <sroberts / uniserve.com> 2003 (with modifications).

This file is distributed under the same terms as Ruby.

Defined Under Namespace

Classes: Unparseable

Constant Summary collapse

WORD =

:nodoc:

/=\?([!#$\%&'*+-\/0-9A-Z\\^\`a-z{|}~]+)\?([BbQq])\?([!->@-~]+)\?=/
ADJACENT_WORDS =

Look for two adjacent words in the same encoding.

/(#{WORD})[\s\r\n]+(?==\?(\2)\?([BbQq])\?)/

Class Method Summary collapse

Class Method Details

.decode(from, target = 'utf-8') ⇒ Object

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.



24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
 
# 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