lisp/mail/mail-utils.el

   1 ;;; mail-utils.el --- utility functions used both by rmail and rnews
   2
   3 ;; Copyright (C) 1985, 2001 Free Software Foundation, Inc.
   4
   5 ;; Maintainer: FSF
   6 ;; Keywords: mail, news
   7
   8 ;; This file is part of GNU Emacs.
   9
  10 ;; GNU Emacs is free software; you can redistribute it and/or modify
  11 ;; it under the terms of the GNU General Public License as published by
  12 ;; the Free Software Foundation; either version 2, or (at your option)
  13 ;; any later version.
  14
  15 ;; GNU Emacs is distributed in the hope that it will be useful,
  16 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  17 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18 ;; GNU General Public License for more details.
  19
  20 ;; You should have received a copy of the GNU General Public License
  21 ;; along with GNU Emacs; see the file COPYING.  If not, write to the
  22 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  23 ;; Boston, MA 02111-1307, USA.
  24
  25 ;;; Commentary:
  26
  27 ;; Utility functions for mail and netnews handling.  These handle fine
  28 ;; points of header parsing.
  29
  30 ;;; Code:
  31
  32 ;;; We require lisp-mode to make sure that lisp-mode-syntax-table has
  33 ;;; been initialized.
  34 (require 'lisp-mode)
  35
  36 ;;;###autoload
  37 (defcustom mail-use-rfc822 nil "\
  38 *If non-nil, use a full, hairy RFC822 parser on mail addresses.
  39 Otherwise, (the default) use a smaller, somewhat faster, and
  40 often correct parser."
  41   :type 'boolean
  42   :group 'mail)
  43
  44 ;; Returns t if file FILE is an Rmail file.
  45 ;;;###autoload
  46 (defun mail-file-babyl-p (file)
  47   (let ((buf (generate-new-buffer " *rmail-file-p*")))
  48     (unwind-protect
  49         (save-excursion
  50           (set-buffer buf)
  51           (insert-file-contents file nil 0 100)
  52           (looking-at "BABYL OPTIONS:"))
  53       (kill-buffer buf))))
  54
  55 (defun mail-string-delete (string start end)
  56   "Returns a string containing all of STRING except the part
  57 from START (inclusive) to END (exclusive)."
  58   (if (null end) (substring string 0 start)
  59     (concat (substring string 0 start)
  60             (substring string end nil))))
  61
  62 ;;;###autoload
  63 (defun mail-quote-printable (string &optional wrapper)
  64   "Convert a string to the \"quoted printable\" Q encoding.
  65 If the optional argument WRAPPER is non-nil,
  66 we add the wrapper characters =?ISO-8859-1?Q?....?=."
  67   (let ((i 0) (result ""))
  68     (save-match-data
  69       (while (string-match "[?=\"\200-\377]" string i)
  70         (setq result
  71               (concat result (substring string i (match-beginning 0))
  72                       (upcase (format "=%02x"
  73                                       (aref string (match-beginning 0))))))
  74         (setq i (match-end 0)))
  75       (if wrapper
  76           (concat "=?ISO-8859-1?Q?"
  77                   result (substring string i)
  78                   "?=")
  79         (concat result (substring string i))))))
  80
  81 (defun mail-unquote-printable-hexdigit (char)
  82   (if (>= char ?A)
  83       (+ (- char ?A) 10)
  84     (- char ?0)))
  85
  86 ;;;###autoload
  87 (defun mail-unquote-printable (string &optional wrapper)
  88   "Undo the \"quoted printable\" encoding.
  89 If the optional argument WRAPPER is non-nil,
  90 we expect to find and remove the wrapper characters =?ISO-8859-1?Q?....?=."
  91   (save-match-data
  92     (and wrapper
  93          (string-match "\\`=\\?ISO-8859-1\\?Q\\?\\([^?]*\\)\\?" string)
  94          (setq string (match-string 1 string)))
  95     (let ((i 0) strings)
  96       (while (string-match "=\\(..\\|\n\\)" string i)
  97         (setq strings (cons (substring string i (match-beginning 0)) strings))
  98         (unless (= (aref string (match-beginning 1)) ?\n)
  99           (setq strings
 100                 (cons (make-string 1
 101                                    (+ (* 16 (mail-unquote-printable-hexdigit
 102                                              (aref string (match-beginning 1))))
 103                                       (mail-unquote-printable-hexdigit
 104                                        (aref string (1+ (match-beginning 1))))))
 105                       strings)))
 106         (setq i (match-end 0)))
 107       (apply 'concat (nreverse (cons (substring string i) strings))))))
 108
 109 ;;;###autoload
 110 (defun mail-unquote-printable-region (beg end &optional wrapper)
 111   "Undo the \"quoted printable\" encoding in buffer from BEG to END.
 112 If the optional argument WRAPPER is non-nil,
 113 we expect to find and remove the wrapper characters =?ISO-8859-1?Q?....?=."
 114   (interactive "r\nP")
 115   (save-match-data
 116     (save-excursion
 117       (save-restriction
 118         (narrow-to-region beg end)
 119         (goto-char (point-min))
 120         (when (and wrapper
 121                    (looking-at "\\`=\\?ISO-8859-1\\?Q\\?\\([^?]*\\)\\?"))
 122           (delete-region (match-end 1) end)
 123           (delete-region (point) (match-beginning 1)))
 124         (while (re-search-forward "=\\(..\\|\n\\)" nil t)
 125           (goto-char (match-end 0))
 126           (replace-match
 127            (if (= (char-after (match-beginning 1)) ?\n)
 128                ""
 129              (make-string 1
 130                           (+ (* 16 (mail-unquote-printable-hexdigit
 131                                     (char-after (match-beginning 1))))
 132                              (mail-unquote-printable-hexdigit
 133                               (char-after (1+ (match-beginning 1)))))))
 134            t t))))))
 135
 136 (eval-when-compile (require 'rfc822))
 137
 138 (defun mail-strip-quoted-names (address)
 139   "Delete comments and quoted strings in an address list ADDRESS.
 140 Also delete leading/trailing whitespace and replace FOO <BAR> with just BAR.
 141 Return a modified address list."
 142   (if (null address)
 143       nil
 144     (if mail-use-rfc822
 145         (progn (require 'rfc822)
 146                (mapconcat 'identity (rfc822-addresses address) ", "))
 147       (let (pos)
 148
 149        ;; Detect nested comments.
 150        (if (string-match "[ \t]*(\\([^)\\]\\|\\\\.\\|\\\\\n\\)*(" address)
 151            ;; Strip nested comments.
 152            (with-current-buffer (get-buffer-create " *temp*")
 153              (erase-buffer)
 154              (insert address)
 155              (set-syntax-table lisp-mode-syntax-table)
 156              (goto-char 1)
 157              (while (search-forward "(" nil t)
 158                (forward-char -1)
 159                (skip-chars-backward " \t")
 160                (delete-region (point)
 161                               (save-excursion
 162                                 (condition-case ()
 163                                     (forward-sexp 1)
 164                                   (error (goto-char (point-max))))
 165                                   (point))))
 166              (setq address (buffer-string))
 167              (erase-buffer))
 168          ;; Strip non-nested comments an easier way.
 169          (while (setq pos (string-match
 170                             ;; This doesn't hack rfc822 nested comments
 171                             ;;  `(xyzzy (foo) whinge)' properly.  Big deal.
 172                             "[ \t]*(\\([^)\\]\\|\\\\.\\|\\\\\n\\)*)"
 173                             address))
 174            (setq address (replace-match "" nil nil address 0))))
 175
 176        ;; strip surrounding whitespace
 177        (string-match "\\`[ \t\n]*" address)
 178        (setq address (substring address
 179                                 (match-end 0)
 180                                 (string-match "[ \t\n]*\\'" address
 181                                               (match-end 0))))
 182
 183        ;; strip `quoted' names (This is supposed to hack `"Foo Bar" <bar@host>')
 184        (setq pos 0)
 185        (while (setq pos (string-match
 186                           "\\([ \t]?\\)\\([ \t]*\"\\([^\"\\]\\|\\\\.\\|\\\\\n\\)*\"[ \t\n]*\\)"
 187                           address pos))
 188          ;; If the next thing is "@", we have "foo bar"@host.  Leave it.
 189          (if (and (> (length address) (match-end 0))
 190                   (= (aref address (match-end 0)) ?@))
 191              (setq pos (match-end 0))
 192            ;; Otherwise discard the "..." part.
 193            (setq address (replace-match "" nil nil address 2))))
 194        ;; If this address contains <...>, replace it with just
 195        ;; the part between the <...>.
 196        (while (setq pos (string-match "\\(,\\s-*\\|\\`\\)\\([^,]*<\\([^>,:]*\\)>[^,]*\\)\\(\\s-*,\\|\\'\\)"
 197                                       address))
 198          (setq address (replace-match (match-string 3 address)
 199                                       nil 'literal address 2)))
 200        address))))
 201
 202 ;;; The following piece of ugliness is legacy code.  The name was an
 203 ;;; unfortunate choice --- a flagrant violation of the Emacs Lisp
 204 ;;; coding conventions.  `mail-dont-reply-to' would have been
 205 ;;; infinitely better.  Also, `rmail-dont-reply-to-names' might have
 206 ;;; been better named `mail-dont-reply-to-names' and sourced from this
 207 ;;; file instead of in rmail.el.  Yuck.  -pmr
 208 (defun rmail-dont-reply-to (destinations)
 209   "Prune addresses from DESTINATIONS, a list of recipient addresses.
 210 All addresses matching `rmail-dont-reply-to-names' are removed from
 211 the comma-separated list.  The pruned list is returned."
 212   (if (null rmail-dont-reply-to-names)
 213       (setq rmail-dont-reply-to-names
 214             (concat (if rmail-default-dont-reply-to-names
 215                         (concat rmail-default-dont-reply-to-names "\\|")
 216                       "")
 217                     (if (and user-mail-address
 218                              (not (equal user-mail-address user-login-name)))
 219                         (concat (regexp-quote user-mail-address) "\\|")
 220                       "")
 221                     (concat (regexp-quote user-login-name) "\\>"))))
 222   ;; Split up DESTINATIONS and match each element separately.
 223   (let ((start-pos 0) (cur-pos 0)
 224         (case-fold-search t))
 225     (while start-pos
 226       (setq cur-pos (string-match "[,\"]" destinations cur-pos))
 227       (if (and cur-pos (equal (match-string 0 destinations) "\""))
 228           ;; Search for matching quote.
 229           (let ((next-pos (string-match "\"" destinations (1+ cur-pos))))
 230             (if next-pos
 231                 (setq cur-pos (1+ next-pos))
 232               ;; If the open-quote has no close-quote,
 233               ;; delete the open-quote to get something well-defined.
 234               ;; This case is not valid, but it can happen if things
 235               ;; are weird elsewhere.
 236               (setq destinations (concat (substring destinations 0 cur-pos)
 237                                     (substring destinations (1+ cur-pos))))
 238               (setq cur-pos start-pos)))
 239         (let* ((address (substring destinations start-pos cur-pos))
 240                (naked-address (mail-strip-quoted-names address)))
 241           (if (string-match rmail-dont-reply-to-names naked-address)
 242               (setq destinations (concat (substring destinations 0 start-pos)
 243                                     (and cur-pos (substring destinations
 244                                                             (1+ cur-pos))))
 245                     cur-pos start-pos)
 246             (setq cur-pos (and cur-pos (1+ cur-pos))
 247                   start-pos cur-pos))))))
 248   ;; get rid of any trailing commas
 249   (let ((pos (string-match "[ ,\t\n]*\\'" destinations)))
 250     (if pos
 251         (setq destinations (substring destinations 0 pos))))
 252   ;; remove leading spaces. they bother me.
 253   (if (string-match "\\(\\s \\|,\\)*" destinations)
 254       (substring destinations (match-end 0))
 255     destinations))
 256
 257 \f
 258 ;;;###autoload
 259 (defun mail-fetch-field (field-name &optional last all list)
 260   "Return the value of the header field whose type is FIELD-NAME.
 261 The buffer is expected to be narrowed to just the header of the message.
 262 If second arg LAST is non-nil, use the last field of type FIELD-NAME.
 263 If third arg ALL is non-nil, concatenate all such fields with commas between.
 264 If 4th arg LIST is non-nil, return a list of all such fields."
 265   (save-excursion
 266     (goto-char (point-min))
 267     (let ((case-fold-search t)
 268           (name (concat "^" (regexp-quote field-name) "[ \t]*:[ \t]*")))
 269       (if (or all list)
 270           (let ((value (if all "")))
 271             (while (re-search-forward name nil t)
 272               (let ((opoint (point)))
 273                 (while (progn (forward-line 1)
 274                               (looking-at "[ \t]")))
 275                 ;; Back up over newline, then trailing spaces or tabs
 276                 (forward-char -1)
 277                 (skip-chars-backward " \t" opoint)
 278                 (if list
 279                     (setq value (cons (buffer-substring-no-properties
 280                                        opoint (point))
 281                                       value))
 282                   (setq value (concat value
 283                                       (if (string= value "") "" ", ")
 284                                       (buffer-substring-no-properties
 285                                        opoint (point)))))))
 286             (if list
 287                 value
 288               (and (not (string= value "")) value)))
 289         (if (re-search-forward name nil t)
 290             (progn
 291               (if last (while (re-search-forward name nil t)))
 292               (let ((opoint (point)))
 293                 (while (progn (forward-line 1)
 294                               (looking-at "[ \t]")))
 295                 ;; Back up over newline, then trailing spaces or tabs
 296                 (forward-char -1)
 297                 (skip-chars-backward " \t" opoint)
 298                 (buffer-substring-no-properties opoint (point)))))))))
 299 \f
 300 ;; Parse a list of tokens separated by commas.
 301 ;; It runs from point to the end of the visible part of the buffer.
 302 ;; Whitespace before or after tokens is ignored,
 303 ;; but whitespace within tokens is kept.
 304 (defun mail-parse-comma-list ()
 305   (let (accumulated
 306         beg)
 307     (skip-chars-forward " \t\n")
 308     (while (not (eobp))
 309       (setq beg (point))
 310       (skip-chars-forward "^,")
 311       (skip-chars-backward " \t\n")
 312       (setq accumulated
 313             (cons (buffer-substring-no-properties beg (point))
 314                   accumulated))
 315       (skip-chars-forward "^,")
 316       (skip-chars-forward ", \t\n"))
 317     accumulated))
 318
 319 (defun mail-comma-list-regexp (labels)
 320   (let (pos)
 321     (setq pos (or (string-match "[^ \t]" labels) 0))
 322     ;; Remove leading and trailing whitespace.
 323     (setq labels (substring labels pos (string-match "[ \t]*$" labels pos)))
 324     ;; Change each comma to \|, and flush surrounding whitespace.
 325     (while (setq pos (string-match "[ \t]*,[ \t]*" labels))
 326       (setq labels
 327             (concat (substring labels 0 pos)
 328                     "\\|"
 329                     (substring labels (match-end 0))))))
 330   labels)
 331 \f
 332 (defun mail-rfc822-time-zone (time)
 333   (let* ((sec (or (car (current-time-zone time)) 0))
 334          (absmin (/ (abs sec) 60)))
 335     (format "%c%02d%02d" (if (< sec 0) ?- ?+) (/ absmin 60) (% absmin 60))))
 336
 337 (defun mail-rfc822-date ()
 338   (let* ((time (current-time))
 339          (s (current-time-string time)))
 340     (string-match "[^ ]+ +\\([^ ]+\\) +\\([^ ]+\\) \\([^ ]+\\) \\([^ ]+\\)" s)
 341     (concat (substring s (match-beginning 2) (match-end 2)) " "
 342             (substring s (match-beginning 1) (match-end 1)) " "
 343             (substring s (match-beginning 4) (match-end 4)) " "
 344             (substring s (match-beginning 3) (match-end 3)) " "
 345             (mail-rfc822-time-zone time))))
 346
 347 (provide 'mail-utils)
 348
 349 ;;; mail-utils.el ends here