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emacs/lisp/mail/binhex.el
Lars Ingebrigtsen ec45664d28 Remove XEmacs compat code from binhex.el
* lisp/mail/binhex.el (binhex-insert-char): Remove XEmacs compat
code and made into a function instead of a defalias.
(binhex-decode-region-internal): Remove XEmacs compat code.
2019-06-20 12:51:38 +02:00

331 lines
12 KiB
EmacsLisp

;;; binhex.el --- decode BinHex-encoded text -*- lexical-binding:t -*-
;; Copyright (C) 1998-2019 Free Software Foundation, Inc.
;; Author: Shenghuo Zhu <zsh@cs.rochester.edu>
;; Keywords: binhex news
;; This file is part of GNU Emacs.
;; GNU Emacs is free software: you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation, either version 3 of the License, or
;; (at your option) any later version.
;; GNU Emacs is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
;; GNU General Public License for more details.
;; You should have received a copy of the GNU General Public License
;; along with GNU Emacs. If not, see <https://www.gnu.org/licenses/>.
;;; Commentary:
;; BinHex is a binary-to-text encoding scheme similar to uuencode.
;; The command `binhex-decode-region' decodes BinHex-encoded text, via
;; the external program "hexbin" if that is available, or an Emacs
;; Lisp implementation if not.
;;; Code:
(eval-and-compile
(defalias 'binhex-char-int
(if (fboundp 'char-int)
'char-int
'identity)))
(defgroup binhex nil
"Decoding of BinHex (binary-to-hexadecimal) data."
:group 'mail
:group 'news)
(defcustom binhex-decoder-program "hexbin"
"Non-nil value should be a string that names a binhex decoder.
The program should expect to read binhex data on its standard
input and write the converted data to its standard output."
:type 'string
:group 'binhex)
(defcustom binhex-decoder-switches '("-d")
"List of command line flags passed to the command `binhex-decoder-program'."
:group 'binhex
:type '(repeat string))
(defcustom binhex-use-external
(executable-find binhex-decoder-program)
"Use external binhex program."
:version "22.1"
:group 'binhex
:type 'boolean)
(defconst binhex-alphabet-decoding-alist
'(( ?\! . 0) ( ?\" . 1) ( ?\# . 2) ( ?\$ . 3) ( ?\% . 4) ( ?\& . 5)
( ?\' . 6) ( ?\( . 7) ( ?\) . 8) ( ?\* . 9) ( ?\+ . 10) ( ?\, . 11)
( ?\- . 12) ( ?0 . 13) ( ?1 . 14) ( ?2 . 15) ( ?3 . 16) ( ?4 . 17)
( ?5 . 18) ( ?6 . 19) ( ?8 . 20) ( ?9 . 21) ( ?@ . 22) ( ?A . 23)
( ?B . 24) ( ?C . 25) ( ?D . 26) ( ?E . 27) ( ?F . 28) ( ?G . 29)
( ?H . 30) ( ?I . 31) ( ?J . 32) ( ?K . 33) ( ?L . 34) ( ?M . 35)
( ?N . 36) ( ?P . 37) ( ?Q . 38) ( ?R . 39) ( ?S . 40) ( ?T . 41)
( ?U . 42) ( ?V . 43) ( ?X . 44) ( ?Y . 45) ( ?Z . 46) ( ?\[ . 47)
( ?\` . 48) ( ?a . 49) ( ?b . 50) ( ?c . 51) ( ?d . 52) ( ?e . 53)
( ?f . 54) ( ?h . 55) ( ?i . 56) ( ?j . 57) ( ?k . 58) ( ?l . 59)
( ?m . 60) ( ?p . 61) ( ?q . 62) ( ?r . 63)))
(defun binhex-char-map (char)
(cdr (assq char binhex-alphabet-decoding-alist)))
;;;###autoload
(defconst binhex-begin-line
"^:...............................................................$"
"Regular expression matching the start of a BinHex encoded region.")
(defconst binhex-body-line
"^[^:]...............................................................$")
(defconst binhex-end-line ":$") ; unused
(defvar binhex-temporary-file-directory
(cond ((fboundp 'temp-directory) (temp-directory))
((boundp 'temporary-file-directory) temporary-file-directory)
("/tmp/")))
(defun binhex-insert-char (char &optional count ignored buffer)
"Insert COUNT copies of CHARACTER into BUFFER."
(if (or (null buffer) (eq buffer (current-buffer)))
(insert-char char count)
(with-current-buffer buffer
(insert-char char count))))
(defvar binhex-crc-table
[0 4129 8258 12387 16516 20645 24774 28903
33032 37161 41290 45419 49548 53677 57806 61935
4657 528 12915 8786 21173 17044 29431 25302
37689 33560 45947 41818 54205 50076 62463 58334
9314 13379 1056 5121 25830 29895 17572 21637
42346 46411 34088 38153 58862 62927 50604 54669
13907 9842 5649 1584 30423 26358 22165 18100
46939 42874 38681 34616 63455 59390 55197 51132
18628 22757 26758 30887 2112 6241 10242 14371
51660 55789 59790 63919 35144 39273 43274 47403
23285 19156 31415 27286 6769 2640 14899 10770
56317 52188 64447 60318 39801 35672 47931 43802
27814 31879 19684 23749 11298 15363 3168 7233
60846 64911 52716 56781 44330 48395 36200 40265
32407 28342 24277 20212 15891 11826 7761 3696
65439 61374 57309 53244 48923 44858 40793 36728
37256 33193 45514 41451 53516 49453 61774 57711
4224 161 12482 8419 20484 16421 28742 24679
33721 37784 41979 46042 49981 54044 58239 62302
689 4752 8947 13010 16949 21012 25207 29270
46570 42443 38312 34185 62830 58703 54572 50445
13538 9411 5280 1153 29798 25671 21540 17413
42971 47098 34713 38840 59231 63358 50973 55100
9939 14066 1681 5808 26199 30326 17941 22068
55628 51565 63758 59695 39368 35305 47498 43435
22596 18533 30726 26663 6336 2273 14466 10403
52093 56156 60223 64286 35833 39896 43963 48026
19061 23124 27191 31254 2801 6864 10931 14994
64814 60687 56684 52557 48554 44427 40424 36297
31782 27655 23652 19525 15522 11395 7392 3265
61215 65342 53085 57212 44955 49082 36825 40952
28183 32310 20053 24180 11923 16050 3793 7920])
(defun binhex-update-crc (crc char &optional count)
(if (null count) (setq count 1))
(while (> count 0)
(setq crc (logxor (logand (ash crc 8) 65280)
(aref binhex-crc-table
(logxor (logand (ash crc -8) 255)
char)))
count (1- count)))
crc)
(defun binhex-verify-crc (buffer start end)
(with-current-buffer buffer
(let ((pos start) (crc 0) (last (- end 2)))
(while (< pos last)
(setq crc (binhex-update-crc crc (char-after pos))
pos (1+ pos)))
(if (= crc (binhex-string-big-endian (buffer-substring last end)))
nil
(error "CRC error")))))
(defun binhex-string-big-endian (string)
(let ((ret 0) (i 0) (len (length string)))
(while (< i len)
(setq ret (+ (ash ret 8) (binhex-char-int (aref string i)))
i (1+ i)))
ret))
(defun binhex-string-little-endian (string)
(let ((ret 0) (i 0) (shift 0) (len (length string)))
(while (< i len)
(setq ret (+ ret (ash (binhex-char-int (aref string i)) shift))
i (1+ i)
shift (+ shift 8)))
ret))
(defun binhex-header (buffer)
(with-current-buffer buffer
(let ((pos (point-min)) len)
(vector
(prog1
(setq len (binhex-char-int (char-after pos)))
(setq pos (1+ pos)))
(buffer-substring pos (setq pos (+ pos len)))
(prog1
(setq len (binhex-char-int (char-after pos)))
(setq pos (1+ pos)))
(buffer-substring pos (setq pos (+ pos 4)))
(buffer-substring pos (setq pos (+ pos 4)))
(binhex-string-big-endian
(buffer-substring pos (setq pos (+ pos 2))))
(binhex-string-big-endian
(buffer-substring pos (setq pos (+ pos 4))))
(binhex-string-big-endian
(buffer-substring pos (setq pos (+ pos 4))))))))
(defvar binhex-last-char)
(defvar binhex-repeat)
(defun binhex-push-char (char &optional ignored buffer)
(cond
(binhex-repeat
(if (eq char 0)
(binhex-insert-char (setq binhex-last-char 144) 1
ignored buffer)
(binhex-insert-char binhex-last-char (- char 1)
ignored buffer)
(setq binhex-last-char nil))
(setq binhex-repeat nil))
((= char 144)
(setq binhex-repeat t))
(t
(binhex-insert-char (setq binhex-last-char char) 1 ignored buffer))))
;;;###autoload
(defun binhex-decode-region-internal (start end &optional header-only)
"Binhex decode region between START and END without using an external program.
If HEADER-ONLY is non-nil only decode header and return filename."
(interactive "r")
(let ((work-buffer nil)
(counter 0)
(bits 0) (tmp t)
(lim 0) inputpos
(non-data-chars " \t\n\r:")
file-name-length data-fork-start
header
binhex-last-char binhex-repeat)
(unwind-protect
(save-excursion
(goto-char start)
(when (re-search-forward binhex-begin-line end t)
(setq work-buffer (generate-new-buffer " *binhex-work*"))
(with-current-buffer work-buffer
(set-buffer-multibyte nil))
(beginning-of-line)
(setq bits 0 counter 0)
(while tmp
(skip-chars-forward non-data-chars end)
(setq inputpos (point))
(end-of-line)
(setq lim (point))
(while (and (< inputpos lim)
(setq tmp (binhex-char-map (char-after inputpos))))
(setq bits (+ bits tmp)
counter (1+ counter)
inputpos (1+ inputpos))
(cond ((= counter 4)
(binhex-push-char (ash bits -16) nil work-buffer)
(binhex-push-char (logand (ash bits -8) 255) nil
work-buffer)
(binhex-push-char (logand bits 255) nil
work-buffer)
(setq bits 0 counter 0))
(t (setq bits (ash bits 6)))))
(if (null file-name-length)
(with-current-buffer work-buffer
(setq file-name-length (char-after (point-min))
data-fork-start (+ (point-min)
file-name-length 22))))
(when (and (null header)
(with-current-buffer work-buffer
(>= (buffer-size) data-fork-start)))
(binhex-verify-crc work-buffer
(point-min) data-fork-start)
(setq header (binhex-header work-buffer))
(when header-only (setq tmp nil counter 0)))
(setq tmp (and tmp (not (eq inputpos end)))))
(cond
((= counter 3)
(binhex-push-char (logand (ash bits -16) 255) nil
work-buffer)
(binhex-push-char (logand (ash bits -8) 255) nil
work-buffer))
((= counter 2)
(binhex-push-char (logand (ash bits -10) 255) nil
work-buffer))))
(if header-only nil
(binhex-verify-crc work-buffer
data-fork-start
(+ data-fork-start (aref header 6) 2))
(or (markerp end) (setq end (set-marker (make-marker) end)))
(goto-char start)
(insert-buffer-substring work-buffer
data-fork-start (+ data-fork-start
(aref header 6)))
(delete-region (point) end)))
(and work-buffer (kill-buffer work-buffer)))
(if header (aref header 1))))
;;;###autoload
(defun binhex-decode-region-external (start end)
"Binhex decode region between START and END using external decoder."
(interactive "r")
(let ((cbuf (current-buffer)) firstline work-buffer
(file-name (expand-file-name
(concat (binhex-decode-region-internal start end t)
".data")
binhex-temporary-file-directory)))
(save-excursion
(goto-char start)
(when (re-search-forward binhex-begin-line nil t)
(let ((cdir default-directory) default-process-coding-system)
(unwind-protect
(progn
(set-buffer (setq work-buffer
(generate-new-buffer " *binhex-work*")))
(buffer-disable-undo work-buffer)
(insert-buffer-substring cbuf firstline end)
(cd binhex-temporary-file-directory)
(apply 'call-process-region
(point-min)
(point-max)
binhex-decoder-program
nil
nil
nil
binhex-decoder-switches))
(cd cdir) (set-buffer cbuf)))
(if (and file-name (file-exists-p file-name))
(progn
(goto-char start)
(delete-region start end)
(let (format-alist)
(insert-file-contents-literally file-name)))
(error "Can not binhex")))
(and work-buffer (kill-buffer work-buffer))
(ignore-errors
(if file-name (delete-file file-name))))))
;;;###autoload
(defun binhex-decode-region (start end)
"Binhex decode region between START and END."
(interactive "r")
(if binhex-use-external
(binhex-decode-region-external start end)
(binhex-decode-region-internal start end)))
(provide 'binhex)
;;; binhex.el ends here