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: 1.10 $
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.
35 (require 'std11-parse)
39 (defgroup eword-decode nil
40 "Encoded-word decoding"
47 (defconst eword-decode-RCS-ID
48 "$Id: eword-decode.el,v 1.10 1998-02-25 13:28:53 morioka Exp $")
49 (defconst eword-decode-version (get-version-string eword-decode-RCS-ID))
52 ;;; @ MIME encoded-word definition
55 (defconst eword-encoded-text-regexp "[!->@-~]+")
56 (defconst eword-encoded-word-regexp
57 (concat (regexp-quote "=?")
65 eword-encoded-text-regexp
73 (defconst base64-token-regexp "[A-Za-z0-9+/]")
74 (defconst base64-token-padding-regexp "[A-Za-z0-9+/=]")
76 (defconst eword-B-encoded-text-regexp
85 base64-token-padding-regexp
86 base64-token-padding-regexp
89 ;; (defconst eword-B-encoding-and-encoded-text-regexp
90 ;; (concat "\\(B\\)\\?" eword-B-encoded-text-regexp))
93 ;;; @@ Quoted-Printable
96 (defconst quoted-printable-hex-chars "0123456789ABCDEF")
97 (defconst quoted-printable-octet-regexp
98 (concat "=[" quoted-printable-hex-chars
99 "][" quoted-printable-hex-chars "]"))
101 (defconst eword-Q-encoded-text-regexp
102 (concat "\\([^=?]\\|" quoted-printable-octet-regexp "\\)+"))
103 ;; (defconst eword-Q-encoding-and-encoded-text-regexp
104 ;; (concat "\\(Q\\)\\?" eword-Q-encoded-text-regexp))
110 (defun eword-decode-string (string &optional must-unfold)
111 "Decode MIME encoded-words in STRING.
113 STRING is unfolded before decoding.
115 If an encoded-word is broken or your emacs implementation can not
116 decode the charset included in it, it is not decoded.
118 If MUST-UNFOLD is non-nil, it unfolds and eliminates line-breaks even
119 if there are in decoded encoded-words (generated by bad manner MUA
120 such as a version of Net$cape)."
121 (setq string (std11-unfold-string string))
122 (let ((dest "")(ew nil)
124 (while (and (string-match eword-encoded-word-regexp string)
125 (setq beg (match-beginning 0)
131 (string-match "^[ \t]+$" (substring string 0 beg))
133 (setq dest (concat dest (substring string 0 beg)))
138 (eword-decode-encoded-word
139 (substring string beg end) must-unfold)
141 (setq string (substring string end))
151 (defun eword-decode-region (start end &optional unfolding must-unfold)
152 "Decode MIME encoded-words in region between START and END.
154 If UNFOLDING is not nil, it unfolds before decoding.
156 If MUST-UNFOLD is non-nil, it unfolds and eliminates line-breaks even
157 if there are in decoded encoded-words (generated by bad manner MUA
158 such as a version of Net$cape)."
162 (narrow-to-region start end)
164 (eword-decode-unfold)
166 (goto-char (point-min))
167 (while (re-search-forward (concat "\\(" eword-encoded-word-regexp "\\)"
169 "\\(" eword-encoded-word-regexp "\\)")
171 (replace-match "\\1\\6")
172 (goto-char (point-min))
174 (while (re-search-forward eword-encoded-word-regexp nil t)
175 (insert (eword-decode-encoded-word
177 (buffer-substring (match-beginning 0) (match-end 0))
178 (delete-region (match-beginning 0) (match-end 0))
184 ;;; @ for message header
187 (defcustom eword-decode-ignored-field-list
188 '(newsgroups path lines nntp-posting-host message-id date)
189 "*List of field-names to be ignored when decoding.
190 Each field name must be symbol."
192 :type '(repeat symbol))
194 (defcustom eword-decode-structured-field-list
195 '(reply-to resent-reply-to from resent-from sender resent-sender
196 to resent-to cc resent-cc bcc resent-bcc dcc
197 mime-version content-type content-transfer-encoding
199 "*List of field-names to decode as structured field.
200 Each field name must be symbol."
202 :type '(repeat symbol))
204 (defun eword-decode-header (&optional code-conversion separator)
205 "Decode MIME encoded-words in header fields.
206 If CODE-CONVERSION is nil, it decodes only encoded-words. If it is
207 mime-charset, it decodes non-ASCII bit patterns as the mime-charset.
208 Otherwise it decodes non-ASCII bit patterns as the
209 default-mime-charset.
210 If SEPARATOR is not nil, it is used as header separator."
214 (std11-narrow-to-header separator)
215 (let ((default-charset
217 (if (mime-charset-to-coding-system code-conversion)
219 default-mime-charset))))
221 (let (beg p end field-name len)
222 (goto-char (point-min))
223 (while (re-search-forward std11-field-head-regexp nil t)
224 (setq beg (match-beginning 0)
226 field-name (buffer-substring beg (1- p))
227 len (string-width field-name)
228 field-name (intern (downcase field-name))
229 end (std11-field-end))
230 (cond ((memq field-name eword-decode-ignored-field-list)
233 ((memq field-name eword-decode-structured-field-list)
234 ;; Decode as structured field
235 (let ((body (buffer-substring p end))
236 (default-mime-charset default-charset))
237 (delete-region p end)
238 (insert (eword-decode-and-fold-structured-field
242 ;; Decode as unstructured field
244 (narrow-to-region beg (1+ end))
245 (decode-mime-charset-region p end default-charset)
247 (if (re-search-forward eword-encoded-word-regexp
249 (eword-decode-region beg (point-max) 'unfold))
251 (eword-decode-region (point-min) (point-max) t)
254 (defun eword-decode-unfold ()
255 (goto-char (point-min))
257 (while (re-search-forward std11-field-head-regexp nil t)
258 (setq beg (match-beginning 0)
259 end (std11-field-end))
260 (setq field (buffer-substring beg end))
261 (if (string-match eword-encoded-word-regexp field)
263 (narrow-to-region (goto-char beg) end)
264 (while (re-search-forward "\n\\([ \t]\\)" nil t)
265 (replace-match (match-string 1))
267 (goto-char (point-max))
272 ;;; @ encoded-word decoder
275 (defvar eword-warning-face nil "Face used for invalid encoded-word.")
277 (defun eword-decode-encoded-word (word &optional must-unfold)
278 "Decode WORD if it is an encoded-word.
280 If your emacs implementation can not decode the charset of WORD, it
281 returns WORD. Similarly the encoded-word is broken, it returns WORD.
283 If MUST-UNFOLD is non-nil, it unfolds and eliminates line-breaks even
284 if there are in decoded encoded-word (generated by bad manner MUA such
285 as a version of Net$cape)."
286 (or (if (string-match eword-encoded-word-regexp word)
288 (substring word (match-beginning 1) (match-end 1))
292 (substring word (match-beginning 2) (match-end 2))
295 (substring word (match-beginning 3) (match-end 3))
298 (eword-decode-encoded-text charset encoding text must-unfold)
301 (add-text-properties 0 (length word)
302 (and eword-warning-face
303 (list 'face eword-warning-face))
310 ;;; @ encoded-text decoder
313 (defun eword-decode-encoded-text (charset encoding string
314 &optional must-unfold)
315 "Decode STRING as an encoded-text.
317 If your emacs implementation can not decode CHARSET, it returns nil.
319 If ENCODING is not \"B\" or \"Q\", it occurs error.
320 So you should write error-handling code if you don't want break by errors.
322 If MUST-UNFOLD is non-nil, it unfolds and eliminates line-breaks even
323 if there are in decoded encoded-text (generated by bad manner MUA such
324 as a version of Net$cape)."
325 (let ((cs (mime-charset-to-coding-system charset)))
329 ((string-equal "B" encoding)
330 (if (and (string-match eword-B-encoded-text-regexp string)
331 (string-equal string (match-string 0 string)))
332 (base64-decode-string string)
333 (error "Invalid encoded-text %s" string)))
334 ((string-equal "Q" encoding)
335 (if (and (string-match eword-Q-encoded-text-regexp string)
336 (string-equal string (match-string 0 string)))
337 (q-encoding-decode-string string)
338 (error "Invalid encoded-text %s" string)))
340 (error "Invalid encoding %s" encoding)
345 (setq dest (decode-coding-string dest cs))
352 (t (char-to-string chr)))
354 (std11-unfold-string dest)
360 ;;; @ lexical analyze
363 (defvar eword-lexical-analyze-cache nil)
364 (defvar eword-lexical-analyze-cache-max 299
365 "*Max position of eword-lexical-analyze-cache.
366 It is max size of eword-lexical-analyze-cache - 1.")
368 (defcustom eword-lexical-analyzers
369 '(eword-analyze-quoted-string
370 eword-analyze-domain-literal
371 eword-analyze-comment
373 eword-analyze-special
374 eword-analyze-encoded-word
376 "*List of functions to return result of lexical analyze.
377 Each function must have two arguments: STRING and MUST-UNFOLD.
378 STRING is the target string to be analyzed.
379 If MUST-UNFOLD is not nil, each function must unfold and eliminate
380 bare-CR and bare-LF from the result even if they are included in
381 content of the encoded-word.
382 Each function must return nil if it can not analyze STRING as its
385 Previous function is preferred to next function. If a function
386 returns nil, next function is used. Otherwise the return value will
389 :type '(repeat function))
391 (defun eword-analyze-quoted-string (string &optional must-unfold)
392 (let ((p (std11-check-enclosure string ?\" ?\")))
394 (cons (cons 'quoted-string
395 (decode-mime-charset-string
396 (std11-strip-quoted-pair (substring string 1 (1- p)))
397 default-mime-charset))
398 (substring string p))
401 (defun eword-analyze-domain-literal (string &optional must-unfold)
402 (std11-analyze-domain-literal string))
404 (defun eword-analyze-comment (string &optional must-unfold)
405 (let ((p (std11-check-enclosure string ?\( ?\) t)))
409 (decode-mime-charset-string
410 (std11-strip-quoted-pair (substring string 1 (1- p)))
411 default-mime-charset)
413 (substring string p))
416 (defun eword-analyze-spaces (string &optional must-unfold)
417 (std11-analyze-spaces string))
419 (defun eword-analyze-special (string &optional must-unfold)
420 (std11-analyze-special string))
422 (defun eword-analyze-encoded-word (string &optional must-unfold)
423 (if (eq (string-match eword-encoded-word-regexp string) 0)
424 (let ((end (match-end 0))
425 (dest (eword-decode-encoded-word (match-string 0 string)
428 (setq string (substring string end))
429 (while (eq (string-match `,(concat "[ \t\n]*\\("
430 eword-encoded-word-regexp
434 (setq end (match-end 0))
437 (eword-decode-encoded-word (match-string 1 string)
439 string (substring string end))
441 (cons (cons 'atom dest) string)
444 (defun eword-analyze-atom (string &optional must-unfold)
445 (if (string-match std11-atom-regexp string)
446 (let ((end (match-end 0)))
447 (cons (cons 'atom (decode-mime-charset-string
448 (substring string 0 end)
449 default-mime-charset))
450 (substring string end)
453 (defun eword-lexical-analyze-internal (string must-unfold)
455 (while (not (string-equal string ""))
457 (let ((rest eword-lexical-analyzers)
459 (while (and (setq func (car rest))
460 (null (setq r (funcall func string must-unfold)))
462 (setq rest (cdr rest)))
463 (or r '((error) . ""))
465 (setq dest (cons (car ret) dest))
466 (setq string (cdr ret))
471 (defun eword-lexical-analyze (string &optional must-unfold)
472 "Return lexical analyzed list corresponding STRING.
473 It is like std11-lexical-analyze, but it decodes non us-ascii
474 characters encoded as encoded-words or invalid \"raw\" format.
475 \"Raw\" non us-ascii characters are regarded as variable
476 `default-mime-charset'."
477 (let ((key (copy-sequence string))
479 (set-text-properties 0 (length key) nil key)
480 (if (setq ret (assoc key eword-lexical-analyze-cache))
482 (setq ret (eword-lexical-analyze-internal key must-unfold))
483 (setq eword-lexical-analyze-cache
485 (last eword-lexical-analyze-cache
486 eword-lexical-analyze-cache-max)))
489 (defun eword-decode-token (token)
490 (let ((type (car token))
492 (cond ((eq type 'quoted-string)
493 (std11-wrap-as-quoted-string value))
495 (concat "(" (std11-wrap-as-quoted-pairs value '(?( ?))) ")"))
498 (defun eword-decode-and-fold-structured-field
499 (string start-column &optional max-column must-unfold)
500 "Decode and fold (fill) STRING as structured field body.
501 It decodes non us-ascii characters in FULL-NAME encoded as
502 encoded-words or invalid \"raw\" string. \"Raw\" non us-ascii
503 characters are regarded as variable `default-mime-charset'.
505 If an encoded-word is broken or your emacs implementation can not
506 decode the charset included in it, it is not decoded.
508 If MAX-COLUMN is omitted, `fill-column' is used.
510 If MUST-UNFOLD is non-nil, it unfolds and eliminates line-breaks even
511 if there are in decoded encoded-words (generated by bad manner MUA
512 such as a version of Net$cape)."
514 (setq max-column fill-column))
515 (let ((c start-column)
516 (tokens (eword-lexical-analyze string must-unfold))
519 (let* ((token (car tokens))
521 (setq tokens (cdr tokens))
522 (if (eq type 'spaces)
523 (let* ((next-token (car tokens))
524 (next-str (eword-decode-token next-token))
525 (next-len (string-width next-str))
526 (next-c (+ c next-len 1)))
527 (if (< next-c max-column)
528 (setq result (concat result " " next-str)
530 (setq result (concat result "\n " next-str)
532 (setq tokens (cdr tokens))
534 (let* ((str (eword-decode-token token)))
535 (setq result (concat result str)
536 c (+ c (string-width str)))
540 (defun eword-decode-and-unfold-structured-field (string)
541 "Decode and unfold STRING as structured field body.
542 It decodes non us-ascii characters in FULL-NAME encoded as
543 encoded-words or invalid \"raw\" string. \"Raw\" non us-ascii
544 characters are regarded as variable `default-mime-charset'.
546 If an encoded-word is broken or your emacs implementation can not
547 decode the charset included in it, it is not decoded."
548 (let ((tokens (eword-lexical-analyze string 'must-unfold))
551 (let* ((token (car tokens))
553 (setq tokens (cdr tokens))
555 (if (eq type 'spaces)
557 (concat result (eword-decode-token token))
561 (defun eword-decode-structured-field-body (string &optional must-unfold
562 start-column max-column)
563 "Decode non us-ascii characters in STRING as structured field body.
564 STRING is unfolded before decoding.
566 It decodes non us-ascii characters in FULL-NAME encoded as
567 encoded-words or invalid \"raw\" string. \"Raw\" non us-ascii
568 characters are regarded as variable `default-mime-charset'.
570 If an encoded-word is broken or your emacs implementation can not
571 decode the charset included in it, it is not decoded.
573 If MUST-UNFOLD is non-nil, it unfolds and eliminates line-breaks even
574 if there are in decoded encoded-words (generated by bad manner MUA
575 such as a version of Net$cape)."
577 ;; fold with max-column
578 (eword-decode-and-fold-structured-field
579 string start-column max-column must-unfold)
581 (mapconcat (function eword-decode-token)
582 (eword-lexical-analyze string must-unfold)
586 (defun eword-decode-unstructured-field-body (string &optional must-unfold)
587 "Decode non us-ascii characters in STRING as unstructured field body.
588 STRING is unfolded before decoding.
590 It decodes non us-ascii characters in FULL-NAME encoded as
591 encoded-words or invalid \"raw\" string. \"Raw\" non us-ascii
592 characters are regarded as variable `default-mime-charset'.
594 If an encoded-word is broken or your emacs implementation can not
595 decode the charset included in it, it is not decoded.
597 If MUST-UNFOLD is non-nil, it unfolds and eliminates line-breaks even
598 if there are in decoded encoded-words (generated by bad manner MUA
599 such as a version of Net$cape)."
601 (decode-mime-charset-string string default-mime-charset)
604 (defun eword-extract-address-components (string)
605 "Extract full name and canonical address from STRING.
606 Returns a list of the form (FULL-NAME CANONICAL-ADDRESS).
607 If no name can be extracted, FULL-NAME will be nil.
608 It decodes non us-ascii characters in FULL-NAME encoded as
609 encoded-words or invalid \"raw\" string. \"Raw\" non us-ascii
610 characters are regarded as variable `default-mime-charset'."
611 (let* ((structure (car (std11-parse-address
612 (eword-lexical-analyze
613 (std11-unfold-string string) 'must-unfold))))
614 (phrase (std11-full-name-string structure))
615 (address (std11-address-string structure))
617 (list phrase address)
624 (provide 'eword-decode)
626 ;;; eword-decode.el ends here