mel-q.el

   1 ;;; mel-q.el: Quoted-Printable and Q-encoding encoder/decoder for GNU Emacs
   2
   3 ;; Copyright (C) 1995,1996,1997,1998 Free Software Foundation, Inc.
   4
   5 ;; Author: MORIOKA Tomohiko <morioka@jaist.ac.jp>
   6 ;; Created: 1995/6/25
   7 ;; Keywords: MIME, Quoted-Printable, Q-encoding
   8
   9 ;; This file is part of MEL (MIME Encoding Library).
  10
  11 ;; This program is free software; you can redistribute it and/or
  12 ;; modify it under the terms of the GNU General Public License as
  13 ;; published by the Free Software Foundation; either version 2, or (at
  14 ;; your option) any later version.
  15
  16 ;; This program is distributed in the hope that it will be useful, but
  17 ;; WITHOUT ANY WARRANTY; without even the implied warranty of
  18 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  19 ;; 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., 59 Temple Place - Suite 330,
  24 ;; Boston, MA 02111-1307, USA.
  25
  26 ;;; Code:
  27
  28 (require 'emu)
  29 (require 'mime-def)
  30
  31
  32 ;;; @ Quoted-Printable encoder
  33 ;;;
  34
  35 (defsubst quoted-printable-quote-char (character)
  36   (concat
  37    "="
  38    (char-to-string (aref quoted-printable-hex-chars (ash character -4)))
  39    (char-to-string (aref quoted-printable-hex-chars (logand character 15)))
  40    ))
  41
  42 (defun quoted-printable-internal-encode-region (start end)
  43   (save-excursion
  44     (save-restriction
  45       (narrow-to-region start end)
  46       (goto-char start)
  47       (let ((col 0))
  48         (while (< (point)(point-max))
  49           (cond ((>= col 75)
  50                  (insert "=\n")
  51                  (setq col 0)
  52                  )
  53                 ((looking-at-as-unibyte "^From ")
  54                  (replace-match "=46rom ")
  55                  (backward-char 1)
  56                  (setq col (+ col 6))
  57                  )
  58                 ((looking-at-as-unibyte "[ \t]\n")
  59                  (forward-char 1)
  60                  (insert "=\n")
  61                  (forward-char 1)
  62                  (setq col 0)
  63                  )
  64                 (t
  65                  (let ((chr (char-after (point))))
  66                    (cond ((= chr ?\n)
  67                           (forward-char 1)
  68                           (setq col 0)
  69                           )
  70                          ((or (= chr ?\t)
  71                               (and (<= 32 chr)(/= chr ?=)(< chr 127))
  72                               )
  73                           (forward-char 1)
  74                           (setq col (1+ col))
  75                           )
  76                          ((>= col 73)
  77                           (insert "=\n")
  78                           (setq col 0)
  79                           )
  80                          (t
  81                           (delete-char 1)
  82                           (insert (quoted-printable-quote-char chr))
  83                           (setq col (+ col 3))
  84                           ))
  85                    )))
  86           )))))
  87
  88
  89 (defvar quoted-printable-external-encoder '("mmencode" "-q")
  90   "*list of quoted-printable encoder program name and its arguments.")
  91
  92 (defun quoted-printable-external-encode-region (start end)
  93   (save-excursion
  94     (save-restriction
  95       (narrow-to-region start end)
  96       (as-binary-process
  97        (apply (function call-process-region)
  98               start end (car quoted-printable-external-encoder)
  99               t t nil (cdr quoted-printable-external-encoder))
 100        )
 101       ;; for OS/2
 102       ;;   regularize line break code
 103       (goto-char (point-min))
 104       (while (re-search-forward "\r$" nil t)
 105         (replace-match "")
 106         )
 107       )))
 108
 109
 110 (defvar quoted-printable-internal-encoding-limit
 111   (if (and (featurep 'xemacs)(featurep 'mule))
 112       0
 113     (require 'path-util)
 114     (if (exec-installed-p "mmencode")
 115         1000
 116       (message "Don't found external encoder for Quoted-Printable!")
 117       nil))
 118   "*limit size to use internal quoted-printable encoder.
 119 If size of input to encode is larger than this limit,
 120 external encoder is called.")
 121
 122 (defun quoted-printable-encode-region (start end)
 123   "Encode current region by quoted-printable.
 124 START and END are buffer positions.
 125 This function calls internal quoted-printable encoder if size of
 126 region is smaller than `quoted-printable-internal-encoding-limit',
 127 otherwise it calls external quoted-printable encoder specified by
 128 `quoted-printable-external-encoder'.  In this case, you must install
 129 the program (maybe mmencode included in metamail or XEmacs package)."
 130   (interactive "r")
 131   (if (and quoted-printable-internal-encoding-limit
 132            (> (- end start) quoted-printable-internal-encoding-limit))
 133       (quoted-printable-external-encode-region start end)
 134     (quoted-printable-internal-encode-region start end)
 135     ))
 136
 137
 138 (defun quoted-printable-encode-string (string)
 139   "Encode STRING to quoted-printable, and return the result."
 140   (with-temp-buffer
 141     (insert string)
 142     (quoted-printable-encode-region (point-min)(point-max))
 143     (buffer-string)
 144     ))
 145
 146
 147 (defun quoted-printable-insert-encoded-file (filename)
 148   "Encode contents of file FILENAME to quoted-printable, and insert the result.
 149 It calls external quoted-printable encoder specified by
 150 `quoted-printable-external-encoder'.  So you must install the program
 151 \(maybe mmencode included in metamail or XEmacs package)."
 152   (interactive (list (read-file-name "Insert encoded file: ")))
 153   (apply (function call-process) (car quoted-printable-external-encoder)
 154          filename t nil (cdr quoted-printable-external-encoder))
 155   )
 156
 157
 158 ;;; @ Quoted-Printable decoder
 159 ;;;
 160
 161 (defsubst quoted-printable-hex-char-to-num (chr)
 162   (cond ((<= ?a chr) (+ (- chr ?a) 10))
 163         ((<= ?A chr) (+ (- chr ?A) 10))
 164         ((<= ?0 chr) (- chr ?0))
 165         ))
 166
 167 (defun quoted-printable-decode-string (string)
 168   "Decode STRING which is encoded in quoted-printable, and return the result."
 169   (let (q h l)
 170     (mapconcat (function
 171                 (lambda (chr)
 172                   (cond ((eq chr ?=)
 173                          (setq q t)
 174                          "")
 175                         (q (setq h (quoted-printable-hex-char-to-num chr))
 176                            (setq q nil)
 177                            "")
 178                         (h (setq l (quoted-printable-hex-char-to-num chr))
 179                            (prog1
 180                                (char-to-string (logior (ash h 4) l))
 181                              (setq h nil)
 182                              )
 183                            )
 184                         (t (char-to-string chr))
 185                         )))
 186                string "")))
 187
 188 (defun quoted-printable-internal-decode-region (start end)
 189   (save-excursion
 190     (save-restriction
 191       (narrow-to-region start end)
 192       (goto-char (point-min))
 193       (while (search-forward "=" nil t)
 194         (let ((beg (match-beginning 0)))
 195           (cond ((looking-at "\n")
 196                  (delete-region beg (match-end 0))
 197                  )
 198                 ((looking-at
 199                   `,(concat "[" quoted-printable-hex-chars
 200                             "][" quoted-printable-hex-chars "]"))
 201                  (let* ((end (match-end 0))
 202                         (hex (buffer-substring (match-beginning 0) end)))
 203                    (delete-region beg end)
 204                    (insert
 205                     (logior
 206                      (ash (quoted-printable-hex-char-to-num (aref hex 0)) 4)
 207                      (quoted-printable-hex-char-to-num (aref hex 1))))
 208                    ))
 209                 (t
 210                  ;; invalid
 211                  ))
 212           )))))
 213
 214 (defvar quoted-printable-external-decoder '("mmencode" "-q" "-u")
 215   "*list of quoted-printable decoder program name and its arguments.")
 216
 217 (defun quoted-printable-external-decode-region (start end)
 218   (save-excursion
 219     (as-binary-process
 220      (apply (function call-process-region)
 221             start end (car quoted-printable-external-decoder)
 222             t t nil (cdr quoted-printable-external-decoder))
 223      )))
 224
 225
 226 (defvar quoted-printable-internal-decoding-limit nil
 227   "*limit size to use internal quoted-printable decoder.
 228 If size of input to decode is larger than this limit,
 229 external decoder is called.")
 230
 231 (defun quoted-printable-decode-region (start end)
 232   "Decode current region by quoted-printable.
 233 START and END are buffer positions.
 234 This function calls internal quoted-printable decoder if size of
 235 region is smaller than `quoted-printable-internal-decoding-limit',
 236 otherwise it calls external quoted-printable decoder specified by
 237 `quoted-printable-external-decoder'.  In this case, you must install
 238 the program (maybe mmencode included in metamail or XEmacs package)."
 239   (interactive "r")
 240   (if (and quoted-printable-internal-decoding-limit
 241            (> (- end start) quoted-printable-internal-decoding-limit))
 242       (quoted-printable-external-decode-region start end)
 243     (quoted-printable-internal-decode-region start end)
 244     ))
 245
 246
 247 (defvar quoted-printable-external-decoder-option-to-specify-file '("-o")
 248   "*list of options of quoted-printable decoder program to specify file.")
 249
 250 (defun quoted-printable-write-decoded-region (start end filename)
 251   "Decode and write current region encoded by quoted-printable into FILENAME.
 252 START and END are buffer positions."
 253   (interactive
 254    (list (region-beginning) (region-end)
 255          (read-file-name "Write decoded region to file: ")))
 256   (as-binary-process
 257    (apply (function call-process-region)
 258           start end (car quoted-printable-external-decoder)
 259           nil nil nil
 260           (append (cdr quoted-printable-external-decoder)
 261                   quoted-printable-external-decoder-option-to-specify-file
 262                   (list filename))
 263           )))
 264
 265 \f
 266 ;;; @ Q-encoding encode/decode string
 267 ;;;
 268
 269 (defconst q-encoding-special-chars-alist
 270   '((text       ?= ?? ?_)
 271     (comment    ?= ?? ?_ ?\( ?\) ?\\)
 272     (phrase     ?= ?? ?_ ?\( ?\) ?\\ ?\" ?# ?$ ?% ?& ?' ?, ?. ?/
 273                 ?: ?\; ?< ?> ?@ ?\[ ?\] ?^ ?` ?{ ?| ?} ?~)
 274     ))
 275
 276 (defun q-encoding-encode-string (string &optional mode)
 277   "Encode STRING to Q-encoding of encoded-word, and return the result.
 278 MODE allows `text', `comment', `phrase' or nil.  Default value is
 279 `phrase'."
 280   (let ((specials (cdr (or (assq mode q-encoding-special-chars-alist)
 281                            (assq 'phrase q-encoding-special-chars-alist)
 282                            ))))
 283     (mapconcat (function
 284                 (lambda (chr)
 285                   (cond ((eq chr ? ) "_")
 286                         ((or (< chr 32) (< 126 chr)
 287                              (memq chr specials)
 288                              )
 289                          (quoted-printable-quote-char chr)
 290                          )
 291                         (t
 292                          (char-to-string chr)
 293                          ))
 294                   ))
 295                string "")
 296     ))
 297
 298 (defun q-encoding-decode-string (string)
 299   "Decode STRING which is encoded in Q-encoding and return the result."
 300   (let (q h l)
 301     (mapconcat (function
 302                 (lambda (chr)
 303                   (cond ((eq chr ?_) " ")
 304                         ((eq chr ?=)
 305                          (setq q t)
 306                          "")
 307                         (q (setq h (quoted-printable-hex-char-to-num chr))
 308                            (setq q nil)
 309                            "")
 310                         (h (setq l (quoted-printable-hex-char-to-num chr))
 311                            (prog1
 312                                (char-to-string (logior (ash h 4) l))
 313                              (setq h nil)
 314                              )
 315                            )
 316                         (t (char-to-string chr))
 317                         )))
 318                string "")))
 319
 320
 321 ;;; @@ etc
 322 ;;;
 323
 324 (defun q-encoding-printable-char-p (chr mode)
 325   (and (not (memq chr '(?= ?? ?_)))
 326        (<= ?\   chr)(<= chr ?~)
 327        (cond ((eq mode 'text) t)
 328              ((eq mode 'comment)
 329               (not (memq chr '(?\( ?\) ?\\)))
 330               )
 331              (t
 332               (string-match "[A-Za-z0-9!*+/=_---]" (char-to-string chr))
 333               ))))
 334
 335 (defun q-encoding-encoded-length (string &optional mode)
 336   (let ((l 0)(i 0)(len (length string)) chr)
 337     (while (< i len)
 338       (setq chr (elt string i))
 339       (if (q-encoding-printable-char-p chr mode)
 340           (setq l (+ l 1))
 341         (setq l (+ l 3))
 342         )
 343       (setq i (+ i 1)) )
 344     l))
 345
 346
 347 ;;; @ end
 348 ;;;
 349
 350 (provide 'mel-q)
 351
 352 ;;; mel-q.el ends here