1 ;;; eword-decode.el --- RFC 2047 based encoded-word decoder for GNU Emacs
3 ;; Copyright (C) 1995,1996,1997 Free Software Foundation, Inc.
5 ;; Author: ENAMI Tsugutomo <enami@sys.ptg.sony.co.jp>
6 ;; MORIOKA Tomohiko <morioka@jaist.ac.jp>
7 ;; Maintainer: MORIOKA Tomohiko <morioka@jaist.ac.jp>
9 ;; Original: 1992/07/20 ENAMI Tsugutomo's `mime.el'.
10 ;; Renamed: 1993/06/03 to tiny-mime.el
11 ;; Renamed: 1995/10/03 from tiny-mime.el (split off encoder)
12 ;; Renamed: 1997/02/22 from tm-ew-d.el
13 ;; Version: $Revision: 0.4 $
14 ;; Keywords: encoded-word, MIME, multilingual, header, mail, news
16 ;; This file is part of SEMI (SEMI is Emacs MIME Interfaces).
18 ;; This program is free software; you can redistribute it and/or
19 ;; modify it under the terms of the GNU General Public License as
20 ;; published by the Free Software Foundation; either version 2, or (at
21 ;; your option) any later version.
23 ;; This program is distributed in the hope that it will be useful, but
24 ;; WITHOUT ANY WARRANTY; without even the implied warranty of
25 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
26 ;; General Public License for more details.
28 ;; You should have received a copy of the GNU General Public License
29 ;; along with GNU Emacs; see the file COPYING. If not, write to the
30 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
31 ;; Boston, MA 02111-1307, USA.
44 (defconst eword-decode-RCS-ID
45 "$Id: eword-decode.el,v 0.4 1997-02-24 08:51:06 tmorioka Exp $")
46 (defconst eword-decode-version (get-version-string eword-decode-RCS-ID))
49 ;;; @ MIME encoded-word definition
52 (defconst eword-encoded-text-regexp "[!->@-~]+")
53 (defconst eword-encoded-word-regexp
54 (concat (regexp-quote "=?")
62 eword-encoded-text-regexp
70 (defun eword-decode-string (string &optional must-unfold)
71 "Decode MIME encoded-words in STRING.
73 STRING is unfolded before decoding.
75 If an encoded-word is broken or your emacs implementation can not
76 decode the charset included in it, it is not decoded.
78 If MUST-UNFOLD is non-nil, it unfolds and eliminates line-breaks even
79 if there are in decoded encoded-words (generated by bad manner MUA
80 such as a version of Net$cape)."
81 (setq string (std11-unfold-string string))
82 (let ((dest "")(ew nil)
84 (while (and (string-match eword-encoded-word-regexp string)
85 (setq beg (match-beginning 0)
91 (string-match "^[ \t]+$" (substring string 0 beg))
93 (setq dest (concat dest (substring string 0 beg)))
98 (eword-decode-encoded-word
99 (substring string beg end) must-unfold)
101 (setq string (substring string end))
111 (defun eword-decode-region (start end &optional unfolding must-unfold)
112 "Decode MIME encoded-words in region between START and END.
114 If UNFOLDING is not nil, it unfolds before decoding.
116 If MUST-UNFOLD is non-nil, it unfolds and eliminates line-breaks even
117 if there are in decoded encoded-words (generated by bad manner MUA
118 such as a version of Net$cape)."
122 (narrow-to-region start end)
124 (eword-decode-unfold)
126 (goto-char (point-min))
127 (while (re-search-forward (concat "\\(" eword-encoded-word-regexp "\\)"
129 "\\(" eword-encoded-word-regexp "\\)")
131 (replace-match "\\1\\6")
132 (goto-char (point-min))
134 (let (charset encoding text)
135 (while (re-search-forward eword-encoded-word-regexp nil t)
136 (insert (eword-decode-encoded-word
138 (buffer-substring (match-beginning 0) (match-end 0))
139 (delete-region (match-beginning 0) (match-end 0))
145 ;;; @ for message header
148 (defun eword-decode-header (&optional separator)
149 "Decode MIME encoded-words in header fields.
150 If SEPARATOR is not nil, it is used as header separator."
154 (std11-narrow-to-header separator)
155 (eword-decode-region (point-min) (point-max) t)
158 (defun eword-decode-unfold ()
159 (goto-char (point-min))
161 (while (re-search-forward std11-field-head-regexp nil t)
162 (setq beg (match-beginning 0)
163 end (std11-field-end))
164 (setq field (buffer-substring beg end))
165 (if (string-match eword-encoded-word-regexp field)
167 (narrow-to-region (goto-char beg) end)
168 (while (re-search-forward "\n\\([ \t]\\)" nil t)
169 (replace-match (match-string 1))
171 (goto-char (point-max))
176 ;;; @ encoded-word decoder
179 (defun eword-decode-encoded-word (word &optional must-unfold)
180 "Decode WORD if it is an encoded-word.
182 If your emacs implementation can not decode the charset of WORD, it
183 returns WORD. Similarly the encoded-word is broken, it returns WORD.
185 If MUST-UNFOLD is non-nil, it unfolds and eliminates line-breaks even
186 if there are in decoded encoded-word (generated by bad manner MUA such
187 as a version of Net$cape)."
188 (or (if (string-match eword-encoded-word-regexp word)
190 (substring word (match-beginning 1) (match-end 1))
194 (substring word (match-beginning 2) (match-end 2))
197 (substring word (match-beginning 3) (match-end 3))
200 (eword-decode-encoded-text charset encoding text must-unfold)
202 (and (tl:add-text-properties 0 (length word)
204 (list 'face tm:warning-face))
211 ;;; @ encoded-text decoder
214 (defun eword-decode-encoded-text (charset encoding string
215 &optional must-unfold)
216 "Decode STRING as an encoded-text.
218 If your emacs implementation can not decode CHARSET, it returns nil.
220 If ENCODING is not \"B\" or \"Q\", it occurs error.
221 So you should write error-handling code if you don't want break by errors.
223 If MUST-UNFOLD is non-nil, it unfolds and eliminates line-breaks even
224 if there are in decoded encoded-text (generated by bad manner MUA such
225 as a version of Net$cape)."
226 (let ((cs (mime-charset-to-coding-system charset)))
230 ((string-equal "B" encoding)
231 (if (and (string-match eword-B-encoded-text-regexp string)
232 (string-equal string (match-string 0 string)))
233 (base64-decode-string string)
234 (error "Invalid encoded-text %s" string)))
235 ((string-equal "Q" encoding)
236 (if (and (string-match eword-Q-encoded-text-regexp string)
237 (string-equal string (match-string 0 string)))
238 (q-encoding-decode-string string)
239 (error "Invalid encoded-text %s" string)))
241 (error "Invalid encoding %s" encoding)
246 (setq dest (decode-coding-string dest cs))
253 (t (char-to-string chr)))
255 (std11-unfold-string dest)
264 (provide 'eword-decode)
266 ;;; eword-decode.el ends here