lisp/gnus/uudecode.el

   1 ;;; uudecode.el --- elisp native uudecode
   2
   3 ;; Copyright (c) 1998, 1999, 2000 Free Software Foundation, Inc.
   4
   5 ;; Author: Shenghuo Zhu <zsh@cs.rochester.edu>
   6 ;; Keywords: uudecode 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 ;;     Lots of codes are stolen from mm-decode.el, gnus-uu.el and
  28 ;;     base64.el
  29
  30 ;; This looks as though it could be made rather more efficient for
  31 ;; internal working.  Encoding could use a lookup table and decoding
  32 ;; should presumably use a vector or list buffer for partial results
  33 ;; rather than with-current-buffer.  -- fx
  34
  35 ;; Only `uudecode-decode-region' should be advertised, and whether or
  36 ;; not that uses a program should be customizable, but I guess it's
  37 ;; too late now.  -- fx
  38
  39 ;;; Code:
  40
  41 (eval-when-compile (require 'cl))
  42
  43 (eval-and-compile
  44   (defalias 'uudecode-char-int
  45     (if (fboundp 'char-int)
  46         'char-int
  47       'identity))
  48
  49   (if (featurep 'xemacs)
  50       (defalias 'uudecode-insert-char 'insert-char)
  51     (defun uudecode-insert-char (char &optional count ignored buffer)
  52       (if (or (null buffer) (eq buffer (current-buffer)))
  53           (insert-char char count)
  54         (with-current-buffer buffer
  55           (insert-char char count))))))
  56
  57 (defcustom uudecode-decoder-program "uudecode"
  58   "*Non-nil value should be a string that names a uu decoder.
  59 The program should expect to read uu data on its standard
  60 input and write the converted data to its standard output."
  61   :type 'string
  62   :group 'gnus-extract)
  63
  64 (defcustom uudecode-decoder-switches nil
  65   "*List of command line flags passed to `uudecode-decoder-program'."
  66   :group 'gnus-extract
  67   :type '(repeat string))
  68
  69 (defconst uudecode-alphabet "\040-\140")
  70
  71 (defconst uudecode-begin-line "^begin[ \t]+[0-7][0-7][0-7][ \t]+\\(.*\\)$")
  72 (defconst uudecode-end-line "^end[ \t]*$")
  73
  74 (defconst uudecode-body-line
  75   (let ((i 61) (str "^M"))
  76     (while (> (setq i (1- i)) 0)
  77       (setq str (concat str "[^a-z]")))
  78     (concat str ".?$")))
  79
  80 (defvar uudecode-temporary-file-directory
  81   (cond ((fboundp 'temp-directory) (temp-directory))
  82         ((boundp 'temporary-file-directory) temporary-file-directory)
  83         ("/tmp")))
  84
  85 ;;;###autoload
  86 (defun uudecode-decode-region-external (start end &optional file-name)
  87   "Uudecode region between START and END using external program.
  88 If FILE-NAME is non-nil, save the result to FILE-NAME.  The program
  89 used is specified by `uudecode-decoder-program'."
  90   (interactive "r\nP")
  91   (let ((cbuf (current-buffer)) tempfile firstline status)
  92     (save-excursion
  93       (goto-char start)
  94       (when (re-search-forward uudecode-begin-line nil t)
  95         (forward-line 1)
  96         (setq firstline (point))
  97         (cond ((null file-name))
  98               ((stringp file-name))
  99               (t
 100                (setq file-name (read-file-name "File to Name:"
 101                                                nil nil nil
 102                                                (match-string 1)))))
 103         (setq tempfile (if file-name
 104                            (expand-file-name file-name)
 105                          (let ((temporary-file-directory
 106                                 uudecode-temporary-file-directory))
 107                            (make-temp-file "uu"))))
 108         (let ((cdir default-directory)
 109               default-process-coding-system)
 110           (unwind-protect
 111               (with-temp-buffer
 112                 (insert "begin 600 " (file-name-nondirectory tempfile) "\n")
 113                 (insert-buffer-substring cbuf firstline end)
 114                 (cd (file-name-directory tempfile))
 115                 (apply 'call-process-region
 116                        (point-min)
 117                        (point-max)
 118                        uudecode-decoder-program
 119                        nil
 120                        nil
 121                        nil
 122                        uudecode-decoder-switches))
 123             (cd cdir) (set-buffer cbuf)))
 124         (if (file-exists-p tempfile)
 125             (unless file-name
 126               (goto-char start)
 127               (delete-region start end)
 128               (let (format-alist)
 129                 (insert-file-contents-literally tempfile)))
 130           (message "Can not uudecode")))
 131       (ignore-errors (or file-name (delete-file tempfile))))))
 132
 133 ;;;###autoload
 134 (defun uudecode-decode-region (start end &optional file-name)
 135   "Uudecode region between START and END without using an external program.
 136 If FILE-NAME is non-nil, save the result to FILE-NAME."
 137   (interactive "r\nP")
 138   (let ((work-buffer nil)
 139         (done nil)
 140         (counter 0)
 141         (remain 0)
 142         (bits 0)
 143         (lim 0) inputpos
 144         (non-data-chars (concat "^" uudecode-alphabet)))
 145     (unwind-protect
 146         (save-excursion
 147           (goto-char start)
 148           (when (re-search-forward uudecode-begin-line nil t)
 149             (cond ((null file-name))
 150                   ((stringp file-name))
 151                   (t
 152                    (setq file-name (expand-file-name
 153                                     (read-file-name "File to Name:"
 154                                                     nil nil nil
 155                                                     (match-string 1))))))
 156             (setq work-buffer (generate-new-buffer " *uudecode-work*"))
 157             (forward-line 1)
 158             (skip-chars-forward non-data-chars end)
 159             (while (not done)
 160               (setq inputpos (point))
 161               (setq remain 0 bits 0 counter 0)
 162               (cond
 163                ((> (skip-chars-forward uudecode-alphabet end) 0)
 164                 (setq lim (point))
 165                 (setq remain
 166                       (logand (- (uudecode-char-int (char-after inputpos)) 32)
 167                               63))
 168                 (setq inputpos (1+ inputpos))
 169                 (if (= remain 0) (setq done t))
 170                 (while (and (< inputpos lim) (> remain 0))
 171                   (setq bits (+ bits
 172                                 (logand
 173                                  (-
 174                                   (uudecode-char-int (char-after inputpos)) 32)
 175                                  63)))
 176                   (if (/= counter 0) (setq remain (1- remain)))
 177                   (setq counter (1+ counter)
 178                         inputpos (1+ inputpos))
 179                   (cond ((= counter 4)
 180                          (uudecode-insert-char
 181                           (lsh bits -16) 1 nil work-buffer)
 182                          (uudecode-insert-char
 183                           (logand (lsh bits -8) 255) 1 nil work-buffer)
 184                          (uudecode-insert-char (logand bits 255) 1 nil
 185                                                work-buffer)
 186                          (setq bits 0 counter 0))
 187                         (t (setq bits (lsh bits 6)))))))
 188               (cond
 189                (done)
 190                ((> 0 remain)
 191                 (error "uucode line ends unexpectly")
 192                 (setq done t))
 193                ((and (= (point) end) (not done))
 194                 ;;(error "uucode ends unexpectly")
 195                 (setq done t))
 196                ((= counter 3)
 197                 (uudecode-insert-char (logand (lsh bits -16) 255) 1 nil
 198                                       work-buffer)
 199                 (uudecode-insert-char (logand (lsh bits -8) 255) 1 nil
 200                                       work-buffer))
 201                ((= counter 2)
 202                 (uudecode-insert-char (logand (lsh bits -10) 255) 1 nil
 203                                       work-buffer)))
 204               (skip-chars-forward non-data-chars end))
 205             (if file-name
 206                 (save-excursion
 207                   (set-buffer work-buffer)
 208                   (write-file file-name))
 209               (or (markerp end) (setq end (set-marker (make-marker) end)))
 210               (goto-char start)
 211               (insert-buffer-substring work-buffer)
 212               (delete-region (point) end))))
 213       (and work-buffer (kill-buffer work-buffer)))))
 214
 215 (provide 'uudecode)
 216
 217 ;;; uudecode.el ends here