1;;; mail-utils.el --- utility functions used both by rmail and rnews
2
3;; Copyright (C) 1985, 2001, 2002, 2003, 2004,
4;;   2005, 2006, 2007 Free Software Foundation, Inc.
5
6;; Maintainer: FSF
7;; Keywords: mail, news
8
9;; This file is part of GNU Emacs.
10
11;; GNU Emacs is free software; you can redistribute it and/or modify
12;; it under the terms of the GNU General Public License as published by
13;; the Free Software Foundation; either version 2, or (at your option)
14;; any later version.
15
16;; GNU Emacs is distributed in the hope that it will be useful,
17;; but WITHOUT ANY WARRANTY; without even the implied warranty of
18;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
19;; GNU General Public License for more details.
20
21;; You should have received a copy of the GNU General Public License
22;; along with GNU Emacs; see the file COPYING.  If not, write to the
23;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
24;; Boston, MA 02110-1301, USA.
25
26;;; Commentary:
27
28;; Utility functions for mail and netnews handling.  These handle fine
29;; points of header parsing.
30
31;;; Code:
32
33;;; We require lisp-mode to make sure that lisp-mode-syntax-table has
34;;; been initialized.
35(require 'lisp-mode)
36
37;;;###autoload
38(defcustom mail-use-rfc822 nil "\
39*If non-nil, use a full, hairy RFC822 parser on mail addresses.
40Otherwise, (the default) use a smaller, somewhat faster, and
41often correct parser."
42  :type 'boolean
43  :group 'mail)
44
45;; Returns t if file FILE is an Rmail file.
46;;;###autoload
47(defun mail-file-babyl-p (file)
48  (let ((buf (generate-new-buffer " *rmail-file-p*")))
49    (unwind-protect
50	(save-excursion
51	  (set-buffer buf)
52	  (insert-file-contents file nil 0 100)
53	  (looking-at "BABYL OPTIONS:"))
54      (kill-buffer buf))))
55
56(defun mail-string-delete (string start end)
57  "Returns a string containing all of STRING except the part
58from START (inclusive) to END (exclusive)."
59  (if (null end) (substring string 0 start)
60    (concat (substring string 0 start)
61	    (substring string end nil))))
62
63;;;###autoload
64(defun mail-quote-printable (string &optional wrapper)
65  "Convert a string to the \"quoted printable\" Q encoding.
66If the optional argument WRAPPER is non-nil,
67we add the wrapper characters =?ISO-8859-1?Q?....?=."
68  (let ((i 0) (result ""))
69    (save-match-data
70      (while (string-match "[?=\"\200-\377]" string i)
71	(setq result
72	      (concat result (substring string i (match-beginning 0))
73		      (upcase (format "=%02x"
74				      (aref string (match-beginning 0))))))
75	(setq i (match-end 0)))
76      (if wrapper
77	  (concat "=?ISO-8859-1?Q?"
78		  result (substring string i)
79		  "?=")
80	(concat result (substring string i))))))
81
82(defun mail-unquote-printable-hexdigit (char)
83  (setq char (upcase char))
84  (if (>= char ?A)
85      (+ (- char ?A) 10)
86    (- char ?0)))
87
88;;;###autoload
89(defun mail-unquote-printable (string &optional wrapper)
90  "Undo the \"quoted printable\" encoding.
91If the optional argument WRAPPER is non-nil,
92we expect to find and remove the wrapper characters =?ISO-8859-1?Q?....?=."
93  (save-match-data
94    (and wrapper
95	 (string-match "\\`=\\?ISO-8859-1\\?Q\\?\\([^?]*\\)\\?" string)
96	 (setq string (match-string 1 string)))
97    (let ((i 0) strings)
98      (while (string-match "=\\(..\\|\n\\)" string i)
99	(setq strings (cons (substring string i (match-beginning 0)) strings))
100	(unless (= (aref string (match-beginning 1)) ?\n)
101	  (setq strings
102		(cons (make-string 1
103				   (+ (* 16 (mail-unquote-printable-hexdigit
104					     (aref string (match-beginning 1))))
105				      (mail-unquote-printable-hexdigit
106				       (aref string (1+ (match-beginning 1))))))
107		      strings)))
108	(setq i (match-end 0)))
109      (apply 'concat (nreverse (cons (substring string i) strings))))))
110
111;;;###autoload
112(defun mail-unquote-printable-region (beg end &optional wrapper noerror
113					  unibyte)
114  "Undo the \"quoted printable\" encoding in buffer from BEG to END.
115If the optional argument WRAPPER is non-nil,
116we expect to find and remove the wrapper characters =?ISO-8859-1?Q?....?=.
117If NOERROR is non-nil, return t if successful.
118If UNIBYTE is non-nil, insert converted characters as unibyte.
119That is useful if you are going to character code decoding afterward,
120as Rmail does."
121  (interactive "r\nP")
122  (let (failed)
123    (save-match-data
124      (save-excursion
125	(save-restriction
126	  (narrow-to-region beg end)
127	  (goto-char (point-min))
128	  (when (and wrapper
129		     (looking-at "\\`=\\?ISO-8859-1\\?Q\\?\\([^?]*\\)\\?"))
130	    (delete-region (match-end 1) end)
131	    (delete-region (point) (match-beginning 1)))
132	  (while (re-search-forward "=\\(\\([0-9A-F][0-9A-F]\\)\\|[=\n]\\|..\\)" nil t)
133	    (goto-char (match-end 0))
134	    (cond ((= (char-after (match-beginning 1)) ?\n)
135		   (replace-match ""))
136		  ((= (char-after (match-beginning 1)) ?=)
137		   (replace-match "="))
138		  ((match-beginning 2)
139		   (let ((char (+ (* 16 (mail-unquote-printable-hexdigit
140					 (char-after (match-beginning 2))))
141				  (mail-unquote-printable-hexdigit
142				   (char-after (1+ (match-beginning 2)))))))
143		     (if unibyte
144			 (progn
145			   (replace-match "")
146			   ;; insert-char will insert this as unibyte,
147			   (insert-char char 1))
148		       (replace-match (make-string 1 char) t t))))
149		  (noerror
150		   (setq failed t))
151		  (t
152		   (error "Malformed MIME quoted-printable message"))))
153	  (not failed))))))
154
155(eval-when-compile (require 'rfc822))
156
157(defun mail-strip-quoted-names (address)
158  "Delete comments and quoted strings in an address list ADDRESS.
159Also delete leading/trailing whitespace and replace FOO <BAR> with just BAR.
160Return a modified address list."
161  (if (null address)
162      nil
163    (if mail-use-rfc822
164	(progn (require 'rfc822)
165	       (mapconcat 'identity (rfc822-addresses address) ", "))
166      (let (pos)
167
168       ;; Detect nested comments.
169       (if (string-match "[ \t]*(\\([^)\\]\\|\\\\.\\|\\\\\n\\)*(" address)
170	   ;; Strip nested comments.
171	   (with-current-buffer (get-buffer-create " *temp*")
172	     (erase-buffer)
173	     (insert address)
174	     (set-syntax-table lisp-mode-syntax-table)
175	     (goto-char 1)
176	     (while (search-forward "(" nil t)
177	       (forward-char -1)
178	       (skip-chars-backward " \t")
179	       (delete-region (point)
180			      (save-excursion
181				(condition-case ()
182				    (forward-sexp 1)
183				  (error (goto-char (point-max))))
184				  (point))))
185	     (setq address (buffer-string))
186	     (erase-buffer))
187	 ;; Strip non-nested comments an easier way.
188	 (while (setq pos (string-match
189			    ;; This doesn't hack rfc822 nested comments
190			    ;;  `(xyzzy (foo) whinge)' properly.  Big deal.
191			    "[ \t]*(\\([^)\\]\\|\\\\.\\|\\\\\n\\)*)"
192			    address))
193	   (setq address (replace-match "" nil nil address 0))))
194
195       ;; strip surrounding whitespace
196       (string-match "\\`[ \t\n]*" address)
197       (setq address (substring address
198				(match-end 0)
199				(string-match "[ \t\n]*\\'" address
200					      (match-end 0))))
201
202       ;; strip `quoted' names (This is supposed to hack `"Foo Bar" <bar@host>')
203       (setq pos 0)
204       (while (setq pos (string-match
205                          "\\([ \t]?\\)\\([ \t]*\"\\([^\"\\]\\|\\\\.\\|\\\\\n\\)*\"[ \t\n]*\\)"
206			  address pos))
207	 ;; If the next thing is "@", we have "foo bar"@host.  Leave it.
208	 (if (and (> (length address) (match-end 0))
209		  (= (aref address (match-end 0)) ?@))
210	     (setq pos (match-end 0))
211	   ;; Otherwise discard the "..." part.
212	   (setq address (replace-match "" nil nil address 2))))
213       ;; If this address contains <...>, replace it with just
214       ;; the part between the <...>.
215       (while (setq pos (string-match "\\(,\\s-*\\|\\`\\)\\([^,]*<\\([^>,:]*\\)>[^,]*\\)\\(\\s-*,\\|\\'\\)"
216				      address))
217	 (setq address (replace-match (match-string 3 address)
218				      nil 'literal address 2)))
219       address))))
220
221;;; The following piece of ugliness is legacy code.  The name was an
222;;; unfortunate choice --- a flagrant violation of the Emacs Lisp
223;;; coding conventions.  `mail-dont-reply-to' would have been
224;;; infinitely better.  Also, `rmail-dont-reply-to-names' might have
225;;; been better named `mail-dont-reply-to-names' and sourced from this
226;;; file instead of in rmail.el.  Yuck.  -pmr
227(defun rmail-dont-reply-to (destinations)
228  "Prune addresses from DESTINATIONS, a list of recipient addresses.
229All addresses matching `rmail-dont-reply-to-names' are removed from
230the comma-separated list.  The pruned list is returned."
231  (if (null rmail-dont-reply-to-names)
232      (setq rmail-dont-reply-to-names
233	    (concat (if rmail-default-dont-reply-to-names
234			(concat rmail-default-dont-reply-to-names "\\|")
235                      "")
236                    (if (and user-mail-address
237                             (not (equal user-mail-address user-login-name)))
238			;; Anchor the login name and email address so
239			;; that we don't match substrings: if the
240			;; login name is "foo", we shouldn't match
241			;; "barfoo@baz.com".
242                        (concat "\\`"
243				(regexp-quote user-mail-address)
244				"\\'\\|")
245                      "")
246                    (concat "\\`" (regexp-quote user-login-name) "@"))))
247  ;; Split up DESTINATIONS and match each element separately.
248  (let ((start-pos 0) (cur-pos 0)
249	(case-fold-search t))
250    (while start-pos
251      (setq cur-pos (string-match "[,\"]" destinations cur-pos))
252      (if (and cur-pos (equal (match-string 0 destinations) "\""))
253	  ;; Search for matching quote.
254	  (let ((next-pos (string-match "\"" destinations (1+ cur-pos))))
255	    (if next-pos
256		(setq cur-pos (1+ next-pos))
257	      ;; If the open-quote has no close-quote,
258	      ;; delete the open-quote to get something well-defined.
259	      ;; This case is not valid, but it can happen if things
260	      ;; are weird elsewhere.
261	      (setq destinations (concat (substring destinations 0 cur-pos)
262				    (substring destinations (1+ cur-pos))))
263	      (setq cur-pos start-pos)))
264	(let* ((address (substring destinations start-pos cur-pos))
265	       (naked-address (mail-strip-quoted-names address)))
266	  (if (string-match rmail-dont-reply-to-names naked-address)
267	      (setq destinations (concat (substring destinations 0 start-pos)
268				    (and cur-pos (substring destinations
269							    (1+ cur-pos))))
270		    cur-pos start-pos)
271	    (setq cur-pos (and cur-pos (1+ cur-pos))
272		  start-pos cur-pos))))))
273  ;; get rid of any trailing commas
274  (let ((pos (string-match "[ ,\t\n]*\\'" destinations)))
275    (if pos
276        (setq destinations (substring destinations 0 pos))))
277  ;; remove leading spaces. they bother me.
278  (if (string-match "\\(\\s \\|,\\)*" destinations)
279      (substring destinations (match-end 0))
280    destinations))
281
282
283;;;###autoload
284(defun mail-fetch-field (field-name &optional last all list)
285  "Return the value of the header field whose type is FIELD-NAME.
286The buffer is expected to be narrowed to just the header of the message.
287If second arg LAST is non-nil, use the last field of type FIELD-NAME.
288If third arg ALL is non-nil, concatenate all such fields with commas between.
289If 4th arg LIST is non-nil, return a list of all such fields."
290  (save-excursion
291    (goto-char (point-min))
292    (let ((case-fold-search t)
293	  (name (concat "^" (regexp-quote field-name) "[ \t]*:[ \t]*")))
294      (if (or all list)
295	  (let ((value (if all "")))
296	    (while (re-search-forward name nil t)
297	      (let ((opoint (point)))
298		(while (progn (forward-line 1)
299			      (looking-at "[ \t]")))
300		;; Back up over newline, then trailing spaces or tabs
301		(forward-char -1)
302		(skip-chars-backward " \t" opoint)
303		(if list
304		    (setq value (cons (buffer-substring-no-properties
305				       opoint (point))
306				      value))
307		  (setq value (concat value
308				      (if (string= value "") "" ", ")
309				      (buffer-substring-no-properties
310				       opoint (point)))))))
311	    (if list
312		value
313	      (and (not (string= value "")) value)))
314	(if (re-search-forward name nil t)
315	    (progn
316	      (if last (while (re-search-forward name nil t)))
317	      (let ((opoint (point)))
318		(while (progn (forward-line 1)
319			      (looking-at "[ \t]")))
320		;; Back up over newline, then trailing spaces or tabs
321		(forward-char -1)
322		(skip-chars-backward " \t" opoint)
323		(buffer-substring-no-properties opoint (point)))))))))
324
325;; Parse a list of tokens separated by commas.
326;; It runs from point to the end of the visible part of the buffer.
327;; Whitespace before or after tokens is ignored,
328;; but whitespace within tokens is kept.
329(defun mail-parse-comma-list ()
330  (let (accumulated
331	beg)
332    (skip-chars-forward " \t\n")
333    (while (not (eobp))
334      (setq beg (point))
335      (skip-chars-forward "^,")
336      (skip-chars-backward " \t\n")
337      (setq accumulated
338	    (cons (buffer-substring-no-properties beg (point))
339		  accumulated))
340      (skip-chars-forward "^,")
341      (skip-chars-forward ", \t\n"))
342    accumulated))
343
344(defun mail-comma-list-regexp (labels)
345  (let (pos)
346    (setq pos (or (string-match "[^ \t]" labels) 0))
347    ;; Remove leading and trailing whitespace.
348    (setq labels (substring labels pos (string-match "[ \t]*$" labels pos)))
349    ;; Change each comma to \|, and flush surrounding whitespace.
350    (while (setq pos (string-match "[ \t]*,[ \t]*" labels))
351      (setq labels
352	    (concat (substring labels 0 pos)
353		    "\\|"
354		    (substring labels (match-end 0))))))
355  labels)
356
357(defun mail-rfc822-time-zone (time)
358  (let* ((sec (or (car (current-time-zone time)) 0))
359	 (absmin (/ (abs sec) 60)))
360    (format "%c%02d%02d" (if (< sec 0) ?- ?+) (/ absmin 60) (% absmin 60))))
361
362(defun mail-rfc822-date ()
363  (let* ((time (current-time))
364	 (s (current-time-string time)))
365    (string-match "[^ ]+ +\\([^ ]+\\) +\\([^ ]+\\) \\([^ ]+\\) \\([^ ]+\\)" s)
366    (concat (substring s (match-beginning 2) (match-end 2)) " "
367	    (substring s (match-beginning 1) (match-end 1)) " "
368	    (substring s (match-beginning 4) (match-end 4)) " "
369	    (substring s (match-beginning 3) (match-end 3)) " "
370	    (mail-rfc822-time-zone time))))
371
372(provide 'mail-utils)
373
374;;; arch-tag: b24aec2f-fd65-4ceb-9e39-3cc2827036fd
375;;; mail-utils.el ends here
376