(info-xref-xfile-alist, info-xref-filename-heading, info-xref-good,
[emacs.git] / lisp / gnus / binhex.el
blobaf0669f62aa0a73e803ea095cbda269367166c45
1 ;;; binhex.el --- elisp native binhex decode
3 ;; Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2004,
4 ;; 2005 Free Software Foundation, Inc.
6 ;; Author: Shenghuo Zhu <zsh@cs.rochester.edu>
7 ;; Keywords: binhex news
9 ;; This file is part of GNU Emacs.
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.
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.
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.
26 ;;; Commentary:
28 ;;; Code:
30 (autoload 'executable-find "executable")
32 (eval-when-compile (require 'cl))
34 (eval-and-compile
35 (defalias 'binhex-char-int
36 (if (fboundp 'char-int)
37 'char-int
38 'identity)))
40 (defcustom binhex-decoder-program "hexbin"
41 "*Non-nil value should be a string that names a binhex decoder.
42 The program should expect to read binhex data on its standard
43 input and write the converted data to its standard output."
44 :type 'string
45 :group 'gnus-extract)
47 (defcustom binhex-decoder-switches '("-d")
48 "*List of command line flags passed to the command `binhex-decoder-program'."
49 :group 'gnus-extract
50 :type '(repeat string))
52 (defcustom binhex-use-external
53 (executable-find binhex-decoder-program)
54 "*Use external binhex program."
55 :version "22.1"
56 :group 'gnus-extract
57 :type 'boolean)
59 (defconst binhex-alphabet-decoding-alist
60 '(( ?\! . 0) ( ?\" . 1) ( ?\# . 2) ( ?\$ . 3) ( ?\% . 4) ( ?\& . 5)
61 ( ?\' . 6) ( ?\( . 7) ( ?\) . 8) ( ?\* . 9) ( ?\+ . 10) ( ?\, . 11)
62 ( ?\- . 12) ( ?0 . 13) ( ?1 . 14) ( ?2 . 15) ( ?3 . 16) ( ?4 . 17)
63 ( ?5 . 18) ( ?6 . 19) ( ?8 . 20) ( ?9 . 21) ( ?@ . 22) ( ?A . 23)
64 ( ?B . 24) ( ?C . 25) ( ?D . 26) ( ?E . 27) ( ?F . 28) ( ?G . 29)
65 ( ?H . 30) ( ?I . 31) ( ?J . 32) ( ?K . 33) ( ?L . 34) ( ?M . 35)
66 ( ?N . 36) ( ?P . 37) ( ?Q . 38) ( ?R . 39) ( ?S . 40) ( ?T . 41)
67 ( ?U . 42) ( ?V . 43) ( ?X . 44) ( ?Y . 45) ( ?Z . 46) ( ?\[ . 47)
68 ( ?\` . 48) ( ?a . 49) ( ?b . 50) ( ?c . 51) ( ?d . 52) ( ?e . 53)
69 ( ?f . 54) ( ?h . 55) ( ?i . 56) ( ?j . 57) ( ?k . 58) ( ?l . 59)
70 ( ?m . 60) ( ?p . 61) ( ?q . 62) ( ?r . 63)))
72 (defun binhex-char-map (char)
73 (cdr (assq char binhex-alphabet-decoding-alist)))
75 ;;;###autoload
76 (defconst binhex-begin-line
77 "^:...............................................................$")
78 (defconst binhex-body-line
79 "^[^:]...............................................................$")
80 (defconst binhex-end-line ":$")
82 (defvar binhex-temporary-file-directory
83 (cond ((fboundp 'temp-directory) (temp-directory))
84 ((boundp 'temporary-file-directory) temporary-file-directory)
85 ("/tmp/")))
87 (eval-and-compile
88 (defalias 'binhex-insert-char
89 (if (featurep 'xemacs)
90 'insert-char
91 (lambda (char &optional count ignored buffer)
92 "Insert COUNT copies of CHARACTER into BUFFER."
93 (if (or (null buffer) (eq buffer (current-buffer)))
94 (insert-char char count)
95 (with-current-buffer buffer
96 (insert-char char count)))))))
98 (defvar binhex-crc-table
99 [0 4129 8258 12387 16516 20645 24774 28903
100 33032 37161 41290 45419 49548 53677 57806 61935
101 4657 528 12915 8786 21173 17044 29431 25302
102 37689 33560 45947 41818 54205 50076 62463 58334
103 9314 13379 1056 5121 25830 29895 17572 21637
104 42346 46411 34088 38153 58862 62927 50604 54669
105 13907 9842 5649 1584 30423 26358 22165 18100
106 46939 42874 38681 34616 63455 59390 55197 51132
107 18628 22757 26758 30887 2112 6241 10242 14371
108 51660 55789 59790 63919 35144 39273 43274 47403
109 23285 19156 31415 27286 6769 2640 14899 10770
110 56317 52188 64447 60318 39801 35672 47931 43802
111 27814 31879 19684 23749 11298 15363 3168 7233
112 60846 64911 52716 56781 44330 48395 36200 40265
113 32407 28342 24277 20212 15891 11826 7761 3696
114 65439 61374 57309 53244 48923 44858 40793 36728
115 37256 33193 45514 41451 53516 49453 61774 57711
116 4224 161 12482 8419 20484 16421 28742 24679
117 33721 37784 41979 46042 49981 54044 58239 62302
118 689 4752 8947 13010 16949 21012 25207 29270
119 46570 42443 38312 34185 62830 58703 54572 50445
120 13538 9411 5280 1153 29798 25671 21540 17413
121 42971 47098 34713 38840 59231 63358 50973 55100
122 9939 14066 1681 5808 26199 30326 17941 22068
123 55628 51565 63758 59695 39368 35305 47498 43435
124 22596 18533 30726 26663 6336 2273 14466 10403
125 52093 56156 60223 64286 35833 39896 43963 48026
126 19061 23124 27191 31254 2801 6864 10931 14994
127 64814 60687 56684 52557 48554 44427 40424 36297
128 31782 27655 23652 19525 15522 11395 7392 3265
129 61215 65342 53085 57212 44955 49082 36825 40952
130 28183 32310 20053 24180 11923 16050 3793 7920])
132 (defun binhex-update-crc (crc char &optional count)
133 (if (null count) (setq count 1))
134 (while (> count 0)
135 (setq crc (logxor (logand (lsh crc 8) 65280)
136 (aref binhex-crc-table
137 (logxor (logand (lsh crc -8) 255)
138 char)))
139 count (1- count)))
140 crc)
142 (defun binhex-verify-crc (buffer start end)
143 (with-current-buffer buffer
144 (let ((pos start) (crc 0) (last (- end 2)))
145 (while (< pos last)
146 (setq crc (binhex-update-crc crc (char-after pos))
147 pos (1+ pos)))
148 (if (= crc (binhex-string-big-endian (buffer-substring last end)))
150 (error "CRC error")))))
152 (defun binhex-string-big-endian (string)
153 (let ((ret 0) (i 0) (len (length string)))
154 (while (< i len)
155 (setq ret (+ (lsh ret 8) (binhex-char-int (aref string i)))
156 i (1+ i)))
157 ret))
159 (defun binhex-string-little-endian (string)
160 (let ((ret 0) (i 0) (shift 0) (len (length string)))
161 (while (< i len)
162 (setq ret (+ ret (lsh (binhex-char-int (aref string i)) shift))
163 i (1+ i)
164 shift (+ shift 8)))
165 ret))
167 (defun binhex-header (buffer)
168 (with-current-buffer buffer
169 (let ((pos (point-min)) len)
170 (vector
171 (prog1
172 (setq len (binhex-char-int (char-after pos)))
173 (setq pos (1+ pos)))
174 (buffer-substring pos (setq pos (+ pos len)))
175 (prog1
176 (setq len (binhex-char-int (char-after pos)))
177 (setq pos (1+ pos)))
178 (buffer-substring pos (setq pos (+ pos 4)))
179 (buffer-substring pos (setq pos (+ pos 4)))
180 (binhex-string-big-endian
181 (buffer-substring pos (setq pos (+ pos 2))))
182 (binhex-string-big-endian
183 (buffer-substring pos (setq pos (+ pos 4))))
184 (binhex-string-big-endian
185 (buffer-substring pos (setq pos (+ pos 4))))))))
187 (defvar binhex-last-char)
188 (defvar binhex-repeat)
190 (defun binhex-push-char (char &optional count ignored buffer)
191 (cond
192 (binhex-repeat
193 (if (eq char 0)
194 (binhex-insert-char (setq binhex-last-char 144) 1
195 ignored buffer)
196 (binhex-insert-char binhex-last-char (- char 1)
197 ignored buffer)
198 (setq binhex-last-char nil))
199 (setq binhex-repeat nil))
200 ((= char 144)
201 (setq binhex-repeat t))
203 (binhex-insert-char (setq binhex-last-char char) 1 ignored buffer))))
205 ;;;###autoload
206 (defun binhex-decode-region-internal (start end &optional header-only)
207 "Binhex decode region between START and END without using an external program.
208 If HEADER-ONLY is non-nil only decode header and return filename."
209 (interactive "r")
210 (let ((work-buffer nil)
211 (counter 0)
212 (bits 0) (tmp t)
213 (lim 0) inputpos
214 (non-data-chars " \t\n\r:")
215 file-name-length data-fork-start
216 header
217 binhex-last-char binhex-repeat)
218 (unwind-protect
219 (save-excursion
220 (goto-char start)
221 (when (re-search-forward binhex-begin-line end t)
222 (let (default-enable-multibyte-characters)
223 (setq work-buffer (generate-new-buffer " *binhex-work*")))
224 (beginning-of-line)
225 (setq bits 0 counter 0)
226 (while tmp
227 (skip-chars-forward non-data-chars end)
228 (setq inputpos (point))
229 (end-of-line)
230 (setq lim (point))
231 (while (and (< inputpos lim)
232 (setq tmp (binhex-char-map (char-after inputpos))))
233 (setq bits (+ bits tmp)
234 counter (1+ counter)
235 inputpos (1+ inputpos))
236 (cond ((= counter 4)
237 (binhex-push-char (lsh bits -16) 1 nil work-buffer)
238 (binhex-push-char (logand (lsh bits -8) 255) 1 nil
239 work-buffer)
240 (binhex-push-char (logand bits 255) 1 nil
241 work-buffer)
242 (setq bits 0 counter 0))
243 (t (setq bits (lsh bits 6)))))
244 (if (null file-name-length)
245 (with-current-buffer work-buffer
246 (setq file-name-length (char-after (point-min))
247 data-fork-start (+ (point-min)
248 file-name-length 22))))
249 (if (and (null header)
250 (with-current-buffer work-buffer
251 (>= (buffer-size) data-fork-start)))
252 (progn
253 (binhex-verify-crc work-buffer
254 (point-min) data-fork-start)
255 (setq header (binhex-header work-buffer))
256 (if header-only (setq tmp nil counter 0))))
257 (setq tmp (and tmp (not (eq inputpos end)))))
258 (cond
259 ((= counter 3)
260 (binhex-push-char (logand (lsh bits -16) 255) 1 nil
261 work-buffer)
262 (binhex-push-char (logand (lsh bits -8) 255) 1 nil
263 work-buffer))
264 ((= counter 2)
265 (binhex-push-char (logand (lsh bits -10) 255) 1 nil
266 work-buffer))))
267 (if header-only nil
268 (binhex-verify-crc work-buffer
269 data-fork-start
270 (+ data-fork-start (aref header 6) 2))
271 (or (markerp end) (setq end (set-marker (make-marker) end)))
272 (goto-char start)
273 (insert-buffer-substring work-buffer
274 data-fork-start (+ data-fork-start
275 (aref header 6)))
276 (delete-region (point) end)))
277 (and work-buffer (kill-buffer work-buffer)))
278 (if header (aref header 1))))
280 ;;;###autoload
281 (defun binhex-decode-region-external (start end)
282 "Binhex decode region between START and END using external decoder."
283 (interactive "r")
284 (let ((cbuf (current-buffer)) firstline work-buffer status
285 (file-name (expand-file-name
286 (concat (binhex-decode-region-internal start end t)
287 ".data")
288 binhex-temporary-file-directory)))
289 (save-excursion
290 (goto-char start)
291 (when (re-search-forward binhex-begin-line nil t)
292 (let ((cdir default-directory) default-process-coding-system)
293 (unwind-protect
294 (progn
295 (set-buffer (setq work-buffer
296 (generate-new-buffer " *binhex-work*")))
297 (buffer-disable-undo work-buffer)
298 (insert-buffer-substring cbuf firstline end)
299 (cd binhex-temporary-file-directory)
300 (apply 'call-process-region
301 (point-min)
302 (point-max)
303 binhex-decoder-program
307 binhex-decoder-switches))
308 (cd cdir) (set-buffer cbuf)))
309 (if (and file-name (file-exists-p file-name))
310 (progn
311 (goto-char start)
312 (delete-region start end)
313 (let (format-alist)
314 (insert-file-contents-literally file-name)))
315 (error "Can not binhex")))
316 (and work-buffer (kill-buffer work-buffer))
317 (ignore-errors
318 (if file-name (delete-file file-name))))))
320 ;;;###autoload
321 (defun binhex-decode-region (start end)
322 "Binhex decode region between START and END."
323 (interactive "r")
324 (if binhex-use-external
325 (binhex-decode-region-external start end)
326 (binhex-decode-region-internal start end)))
328 (provide 'binhex)
330 ;;; arch-tag: 8476badd-1e76-4f1d-a640-f9a38c72eed8
331 ;;; binhex.el ends here