1 ;;; mel.el --- A MIME encoding/decoding library.
3 ;; Copyright (C) 1995,1996,1997,1998,1999 Free Software Foundation, Inc.
5 ;; Author: MORIOKA Tomohiko <tomo@m17n.org>
7 ;; Keywords: MIME, Base64, Quoted-Printable, uuencode, gzip64
9 ;; This file is part of FLIM (Faithful Library about Internet Message).
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.
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.
21 ;; You should have received a copy of the GNU General Public License
22 ;; along with this program; 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.
31 (defcustom mime-encoding-list
32 '("7bit" "8bit" "binary" "base64" "quoted-printable")
33 "List of Content-Transfer-Encoding. Each encoding must be string."
35 :type '(repeat string))
37 (defun mime-encoding-list (&optional service)
38 "Return list of Content-Transfer-Encoding.
39 If SERVICE is specified, it returns available list of
40 Content-Transfer-Encoding for it."
43 (mapatoms (lambda (sym)
45 (setq dest (cons (symbol-name sym) dest)))
47 (symbol-value (intern (format "%s-obarray" service))))
48 (let ((rest mel-encoding-module-alist)
50 (while (setq pair (car rest))
51 (let ((key (car pair)))
54 (setq dest (cons key dest))))
55 (setq rest (cdr rest)))
60 (defun mime-encoding-alist (&optional service)
61 "Return table of Content-Transfer-Encoding for completion."
62 (mapcar #'list (mime-encoding-list service)))
64 (defsubst mel-use-module (name encodings)
66 (set-alist 'mel-encoding-module-alist
68 (cons name (cdr (assoc (car encodings)
69 mel-encoding-module-alist))))
70 (setq encodings (cdr encodings))))
72 (defsubst mel-find-function (service encoding)
73 (mel-find-function-from-obarray
74 (symbol-value (intern (format "%s-obarray" service))) encoding))
77 ;;; @ setting for modules
80 (mel-define-backend "7bit")
81 (mel-define-method-function (mime-encode-string string (nil "7bit"))
83 (mel-define-method-function (mime-decode-string string (nil "7bit"))
85 (mel-define-method mime-encode-region (start end (nil "7bit")))
86 (mel-define-method mime-decode-region (start end (nil "7bit")))
87 (mel-define-method-function (mime-insert-encoded-file filename (nil "7bit"))
88 'binary-insert-file-contents)
89 (mel-define-method-function (mime-write-decoded-region
90 start end filename (nil "7bit"))
93 (mel-define-backend "8bit" ("7bit"))
95 (mel-define-backend "binary" ("8bit"))
98 (and (fboundp 'base64-encode-string)
99 (subrp (symbol-function 'base64-encode-string))))
102 (mel-define-backend "base64")
103 (mel-define-method-function (mime-encode-string string (nil "base64"))
104 'base64-encode-string)
105 (mel-define-method-function (mime-decode-string string (nil "base64"))
106 'base64-decode-string)
107 (mel-define-method-function (mime-encode-region start end (nil "base64"))
108 'base64-encode-region)
109 (mel-define-method-function (mime-decode-region start end (nil "base64"))
110 'base64-decode-region)
111 (mel-define-method mime-insert-encoded-file (filename (nil "base64"))
112 "Encode contents of file FILENAME to base64, and insert the result.
113 It calls external base64 encoder specified by
114 `base64-external-encoder'. So you must install the program (maybe
115 mmencode included in metamail or XEmacs package)."
116 (interactive "*fInsert encoded file: ")
117 (insert (base64-encode-string
119 (set-buffer-multibyte nil)
120 (binary-insert-file-contents filename)
122 (or (bolp) (insert ?\n)))
124 (mel-define-method-function (encoded-text-encode-string string (nil "B"))
125 'base64-encode-string)
126 (mel-define-method encoded-text-decode-string (string (nil "B"))
127 (if (string-match (eval-when-compile
128 (concat "\\`" B-encoded-text-regexp "\\'"))
130 (base64-decode-string string)
131 (error "Invalid encoded-text %s" string)))
134 (mel-use-module 'mel-b-el '("base64" "B"))
135 (mel-use-module 'mel-q '("quoted-printable" "Q"))
136 (mel-use-module 'mel-g '("x-gzip64"))
137 (mel-use-module 'mel-u '("x-uue" "x-uuencode"))
139 (defvar mel-b-ccl-module
140 (and (featurep 'mule)
143 (module-installed-p 'mel-b-ccl))))
145 (defvar mel-q-ccl-module
146 (and (featurep 'mule)
149 (module-installed-p 'mel-q-ccl))))
151 (when mel-b-ccl-module
152 (mel-use-module 'mel-b-ccl '("base64" "B")))
154 (when mel-q-ccl-module
155 (mel-use-module 'mel-q-ccl '("quoted-printable" "Q")))
157 (when base64-dl-module
158 (mel-use-module 'mel-b-dl '("base64" "B")))
165 (defun mime-encode-region (start end encoding)
166 "Encode region START to END of current buffer using ENCODING.
167 ENCODING must be string."
169 (list (region-beginning)(region-end)
170 (completing-read "Encoding: "
171 (mime-encoding-alist)
173 (funcall (mel-find-function 'mime-encode-region encoding) start end))
177 (defun mime-decode-region (start end encoding)
178 "Decode region START to END of current buffer using ENCODING.
179 ENCODING must be string."
181 (list (region-beginning)(region-end)
182 (completing-read "Encoding: "
183 (mime-encoding-alist 'mime-decode-region)
185 (funcall (mel-find-function 'mime-decode-region encoding)
193 (defun mime-decode-string (string encoding)
194 "Decode STRING using ENCODING.
195 ENCODING must be string. If ENCODING is found in
196 `mime-string-decoding-method-alist' as its key, this function decodes
197 the STRING by its value."
198 (let ((f (mel-find-function 'mime-decode-string encoding)))
204 (mel-define-service encoded-text-encode-string (string encoding)
205 "Encode STRING as encoded-text using ENCODING. ENCODING must be string.")
207 (mel-define-service encoded-text-decode-string (string encoding)
208 "Decode STRING as encoded-text using ENCODING. ENCODING must be string.")
210 (defun base64-encoded-length (string)
211 (* (/ (+ (length string) 2) 3) 4))
213 (defsubst Q-encoding-printable-char-p (chr mode)
214 (and (not (memq chr '(?= ?? ?_)))
215 (<= ?\ chr)(<= chr ?~)
216 (cond ((eq mode 'text) t)
218 (not (memq chr '(?\( ?\) ?\\))))
220 (string-match "[A-Za-z0-9!*+/=_---]" (char-to-string chr))))))
222 (defun Q-encoded-text-length (string &optional mode)
223 (let ((l 0)(i 0)(len (length string)) chr)
225 (setq chr (aref string i))
226 (if (or (Q-encoding-printable-char-p chr mode)
238 (defun mime-insert-encoded-file (filename encoding)
239 "Insert file FILENAME encoded by ENCODING format."
241 (list (read-file-name "Insert encoded file: ")
242 (completing-read "Encoding: "
243 (mime-encoding-alist)
245 (funcall (mel-find-function 'mime-insert-encoded-file encoding)
250 (defun mime-write-decoded-region (start end filename encoding)
251 "Decode and write current region encoded by ENCODING into FILENAME.
252 START and END are buffer positions."
254 (list (region-beginning)(region-end)
255 (read-file-name "Write decoded region to file: ")
256 (completing-read "Encoding: "
257 (mime-encoding-alist 'mime-write-decoded-region)
259 (funcall (mel-find-function 'mime-write-decoded-region encoding)
268 ;;; mel.el ends here.