lisp/gnus/uudecode.el

   1 ;;; uudecode.el -- elisp native uudecode
   2
   3 ;; Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2004,
   4 ;;   2005, 2006, 2007 Free Software Foundation, Inc.
   5
   6 ;; Author: Shenghuo Zhu <zsh@cs.rochester.edu>
   7 ;; Keywords: uudecode news
   8
   9 ;; This file is part of GNU Emacs.
  10
  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 3, or (at your option)
  14 ;; any later version.
  15
  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.
  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., 51 Franklin Street, Fifth Floor,
  24 ;; Boston, MA 02110-1301, USA.
  25
  26 ;;; Commentary:
  27
  28 ;;; Code:
  29
  30 (eval-when-compile (require 'cl))
  31
  32 (eval-and-compile
  33   (defalias 'uudecode-char-int
  34     (if (fboundp 'char-int)
  35         'char-int
  36       'identity)))
  37
  38 (defcustom uudecode-decoder-program "uudecode"
  39   "*Non-nil value should be a string that names a uu decoder.
  40 The program should expect to read uu data on its standard
  41 input and write the converted data to its standard output."
  42   :type 'string
  43   :group 'gnus-extract)
  44
  45 (defcustom uudecode-decoder-switches nil
  46   "*List of command line flags passed to `uudecode-decoder-program'."
  47   :group 'gnus-extract
  48   :type '(repeat string))
  49
  50 (defcustom uudecode-use-external
  51   (executable-find uudecode-decoder-program)
  52   "*Use external uudecode program."
  53   :version "22.1"
  54   :group 'gnus-extract
  55   :type 'boolean)
  56
  57 (defconst uudecode-alphabet "\040-\140")
  58
  59 (defconst uudecode-begin-line "^begin[ \t]+[0-7][0-7][0-7][ \t]+\\(.*\\)$")
  60 (defconst uudecode-end-line "^end[ \t]*$")
  61
  62 (defconst uudecode-body-line
  63   (let ((i 61) (str "^M"))
  64     (while (> (setq i (1- i)) 0)
  65       (setq str (concat str "[^a-z]")))
  66     (concat str ".?$")))
  67
  68 (defvar uudecode-temporary-file-directory
  69   (cond ((fboundp 'temp-directory) (temp-directory))
  70         ((boundp 'temporary-file-directory) temporary-file-directory)
  71         ("/tmp")))
  72
  73 ;;;###autoload
  74 (defun uudecode-decode-region-external (start end &optional file-name)
  75   "Uudecode region between START and END using external program.
  76 If FILE-NAME is non-nil, save the result to FILE-NAME.  The program
  77 used is specified by `uudecode-decoder-program'."
  78   (interactive "r\nP")
  79   (let ((cbuf (current-buffer)) tempfile firstline status)
  80     (save-excursion
  81       (goto-char start)
  82       (when (re-search-forward uudecode-begin-line nil t)
  83         (forward-line 1)
  84         (setq firstline (point))
  85         (cond ((null file-name))
  86               ((stringp file-name))
  87               (t
  88                (setq file-name (read-file-name "File to Name:"
  89                                                nil nil nil
  90                                                (match-string 1)))))
  91         (setq tempfile (if file-name
  92                            (expand-file-name file-name)
  93                            (if (fboundp 'make-temp-file)
  94                                (let ((temporary-file-directory
  95                                       uudecode-temporary-file-directory))
  96                                  (make-temp-file "uu"))
  97                              (expand-file-name
  98                               (make-temp-name "uu")
  99                               uudecode-temporary-file-directory))))
 100         (let ((cdir default-directory)
 101               (default-process-coding-system
 102                 (if (featurep 'xemacs)
 103                     ;; In XEmacs, `nil' is not a valid coding system.
 104                     '(binary . binary)
 105                   nil)))
 106           (unwind-protect
 107               (with-temp-buffer
 108                 (insert "begin 600 " (file-name-nondirectory tempfile) "\n")
 109                 (insert-buffer-substring cbuf firstline end)
 110                 (cd (file-name-directory tempfile))
 111                 (apply 'call-process-region
 112                        (point-min)
 113                        (point-max)
 114                        uudecode-decoder-program
 115                        nil
 116                        nil
 117                        nil
 118                        uudecode-decoder-switches))
 119             (cd cdir) (set-buffer cbuf)))
 120         (if (file-exists-p tempfile)
 121             (unless file-name
 122               (goto-char start)
 123               (delete-region start end)
 124               (let (format-alist)
 125                 (insert-file-contents-literally tempfile)))
 126           (message "Can not uudecode")))
 127       (ignore-errors (or file-name (delete-file tempfile))))))
 128
 129 (eval-and-compile
 130   (defalias 'uudecode-string-to-multibyte
 131     (cond
 132      ((featurep 'xemacs)
 133       'identity)
 134      ((fboundp 'string-to-multibyte)
 135       'string-to-multibyte)
 136      (t
 137       (lambda (string)
 138         "Return a multibyte string with the same individual chars as string."
 139         (mapconcat
 140          (lambda (ch) (string-as-multibyte (char-to-string ch)))
 141          string ""))))))
 142
 143 ;;;###autoload
 144 (defun uudecode-decode-region-internal (start end &optional file-name)
 145   "Uudecode region between START and END without using an external program.
 146 If FILE-NAME is non-nil, save the result to FILE-NAME."
 147   (interactive "r\nP")
 148   (let ((done nil)
 149         (counter 0)
 150         (remain 0)
 151         (bits 0)
 152         (lim 0) inputpos result
 153         (non-data-chars (concat "^" uudecode-alphabet)))
 154     (save-excursion
 155       (goto-char start)
 156       (when (re-search-forward uudecode-begin-line nil t)
 157         (cond ((null file-name))
 158               ((stringp file-name))
 159               (t
 160                (setq file-name (expand-file-name
 161                                 (read-file-name "File to Name:"
 162                                                 nil nil nil
 163                                                 (match-string 1))))))
 164         (forward-line 1)
 165         (skip-chars-forward non-data-chars end)
 166         (while (not done)
 167           (setq inputpos (point))
 168           (setq remain 0 bits 0 counter 0)
 169           (cond
 170            ((> (skip-chars-forward uudecode-alphabet end) 0)
 171             (setq lim (point))
 172             (setq remain
 173                   (logand (- (uudecode-char-int (char-after inputpos)) 32)
 174                           63))
 175             (setq inputpos (1+ inputpos))
 176             (if (= remain 0) (setq done t))
 177             (while (and (< inputpos lim) (> remain 0))
 178               (setq bits (+ bits
 179                             (logand
 180                              (-
 181                               (uudecode-char-int (char-after inputpos)) 32)
 182                              63)))
 183               (if (/= counter 0) (setq remain (1- remain)))
 184               (setq counter (1+ counter)
 185                     inputpos (1+ inputpos))
 186               (cond ((= counter 4)
 187                      (setq result (cons
 188                                    (concat
 189                                     (char-to-string (lsh bits -16))
 190                                     (char-to-string (logand (lsh bits -8) 255))
 191                                     (char-to-string (logand bits 255)))
 192                                    result))
 193                      (setq bits 0 counter 0))
 194                     (t (setq bits (lsh bits 6)))))))
 195           (cond
 196            (done)
 197            ((> 0 remain)
 198             (error "uucode line ends unexpectly")
 199             (setq done t))
 200            ((and (= (point) end) (not done))
 201             ;;(error "uucode ends unexpectly")
 202             (setq done t))
 203            ((= counter 3)
 204             (setq result (cons
 205                           (concat
 206                            (char-to-string (logand (lsh bits -16) 255))
 207                            (char-to-string (logand (lsh bits -8) 255)))
 208                           result)))
 209            ((= counter 2)
 210             (setq result (cons
 211                           (char-to-string (logand (lsh bits -10) 255))
 212                           result))))
 213           (skip-chars-forward non-data-chars end))
 214         (if file-name
 215             (let (default-enable-multibyte-characters)
 216               (with-temp-file file-name
 217                 (insert (apply 'concat (nreverse result)))))
 218           (or (markerp end) (setq end (set-marker (make-marker) end)))
 219           (goto-char start)
 220           (if enable-multibyte-characters
 221               (mapc #'(lambda (x) (insert (uudecode-string-to-multibyte x)))
 222                     (nreverse result))
 223             (insert (apply 'concat (nreverse result))))
 224           (delete-region (point) end))))))
 225
 226 ;;;###autoload
 227 (defun uudecode-decode-region (start end &optional file-name)
 228   "Uudecode region between START and END.
 229 If FILE-NAME is non-nil, save the result to FILE-NAME."
 230   (if uudecode-use-external
 231       (uudecode-decode-region-external start end file-name)
 232     (uudecode-decode-region-internal start end file-name)))
 233
 234 (provide 'uudecode)
 235
 236 ;;; arch-tag: e1f09ed5-62b4-4677-9f13-4e81c4fe8ce3
 237 ;;; uudecode.el ends here