344 lines
11 KiB
EmacsLisp

;;; mel.el --- A MIME encoding/decoding library.
;; Copyright (C) 1995,1996,1997,1998,1999,2000 Free Software Foundation, Inc.
;; Author: MORIOKA Tomohiko <tomo@m17n.org>
;; Created: 1995/6/25
;; Keywords: MIME, Base64, Quoted-Printable, uuencode, gzip64
;; This file is part of FLIM (Faithful Library about Internet Message).
;; This program 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 2, or (at
;; your option) any later version.
;; This program 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 this program; see the file COPYING. If not, write to the
;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
;; Boston, MA 02110-1301, USA.
;;; Code:
(require 'mime-def)
(require 'alist)
(defcustom mime-encoding-list
'("7bit" "8bit" "binary" "base64" "quoted-printable")
"List of Content-Transfer-Encoding. Each encoding must be string."
:group 'mime
:type '(repeat string))
(defun mime-encoding-list (&optional service)
"Return list of Content-Transfer-Encoding.
If SERVICE is specified, it returns available list of
Content-Transfer-Encoding for it."
(if service
(let (dest)
(mapatoms (lambda (sym)
(or (eq sym nil)
(setq dest (cons (symbol-name sym) dest)))
)
(symbol-value (intern (format "%s-obarray" service))))
(let ((rest mel-encoding-module-alist)
pair)
(while (setq pair (car rest))
(let ((key (car pair)))
(or (member key dest)
(<= (length key) 1)
(setq dest (cons key dest))))
(setq rest (cdr rest)))
)
dest)
mime-encoding-list))
(defun mime-encoding-alist (&optional service)
"Return table of Content-Transfer-Encoding for completion."
(mapcar #'list (mime-encoding-list service)))
(defsubst mel-use-module (name encodings)
(while encodings
(set-alist 'mel-encoding-module-alist
(car encodings)
(cons name (cdr (assoc (car encodings)
mel-encoding-module-alist))))
(setq encodings (cdr encodings))))
(defsubst mel-find-function (service encoding)
(mel-find-function-from-obarray
(symbol-value (intern (format "%s-obarray" service))) encoding))
;;; @ setting for modules
;;;
(defun 8bit-insert-encoded-file (filename)
"Insert file FILENAME encoded by \"7bit\" format."
(let ((coding-system-for-read 'raw-text)
format-alist)
;; Returns list of absolute file name and length of data inserted.
(insert-file-contents filename)))
(defun 8bit-write-decoded-region (start end filename)
"Decode and write current region encoded by \"8bit\" into FILENAME."
(let ((coding-system-for-write 'raw-text)
format-alist)
(write-region start end filename)))
(mel-define-backend "8bit")
(mel-define-method-function (mime-encode-string string (nil "8bit"))
'identity)
(mel-define-method-function (mime-decode-string string (nil "8bit"))
'identity)
(mel-define-method mime-encode-region (start end (nil "8bit")))
(mel-define-method mime-decode-region (start end (nil "8bit")))
(mel-define-method-function (mime-insert-encoded-file filename (nil "8bit"))
'8bit-insert-encoded-file)
(mel-define-method-function (mime-write-decoded-region
start end filename (nil "8bit"))
'8bit-write-decoded-region)
(defalias '7bit-insert-encoded-file '8bit-insert-encoded-file)
(defalias '7bit-write-decoded-region '8bit-write-decoded-region)
(mel-define-backend "7bit" ("8bit"))
(defun binary-write-decoded-region (start end filename)
"Decode and write current region encoded by \"binary\" into FILENAME."
(let ((coding-system-for-write 'binary)
jka-compr-compression-info-list jam-zcat-filename-list)
(write-region start end filename)))
(defalias 'binary-insert-encoded-file 'insert-file-contents-literally)
(defun binary-find-file-noselect (filename &optional nowarn rawfile)
"Like `find-file-noselect', q.v., but don't code and format conversion."
(let ((coding-system-for-read 'binary)
format-alist)
(find-file-noselect filename nowarn rawfile)))
(defun binary-funcall (name &rest args)
"Like `funcall', q.v., but read and write as binary."
(let ((coding-system-for-read 'binary)
(coding-system-for-write 'binary))
(apply name args)))
(defun binary-to-text-funcall (coding-system name &rest args)
"Like `funcall', q.v., but write as binary and read as text.
Read text is decoded as CODING-SYSTEM."
(let ((coding-system-for-read coding-system)
(coding-system-for-write 'binary))
(apply name args)))
(mel-define-backend "binary")
(mel-define-method-function (mime-encode-string string (nil "binary"))
'identity)
(mel-define-method-function (mime-decode-string string (nil "binary"))
'identity)
(mel-define-method mime-encode-region (start end (nil "binary")))
(mel-define-method mime-decode-region (start end (nil "binary")))
(mel-define-method-function (mime-insert-encoded-file filename (nil "binary"))
'binary-insert-encoded-file)
(mel-define-method-function (mime-write-decoded-region
start end filename (nil "binary"))
'binary-write-decoded-region)
(defvar mel-b-builtin
(and (fboundp 'base64-encode-string)
(subrp (symbol-function 'base64-encode-string))))
(when mel-b-builtin
(mel-define-backend "base64")
(mel-define-method-function (mime-encode-string string (nil "base64"))
'base64-encode-string)
(mel-define-method-function (mime-decode-string string (nil "base64"))
'base64-decode-string)
(mel-define-method-function (mime-encode-region start end (nil "base64"))
'base64-encode-region)
(mel-define-method-function (mime-decode-region start end (nil "base64"))
'base64-decode-region)
(mel-define-method mime-insert-encoded-file (filename (nil "base64"))
"Encode contents of file FILENAME to base64, and insert the result.
It calls external base64 encoder specified by
`base64-external-encoder'. So you must install the program (maybe
mmencode included in metamail or XEmacs package)."
(interactive "*fInsert encoded file: ")
(insert (base64-encode-string
(with-temp-buffer
(set-buffer-multibyte nil)
(binary-insert-encoded-file filename)
(buffer-string))))
(or (bolp) (insert ?\n)))
(mel-define-method mime-write-decoded-region (start end filename
(nil "base64"))
"Decode the region from START to END and write out to FILENAME."
(interactive "*r\nFWrite decoded region to file: ")
(let ((str (buffer-substring start end)))
(with-temp-buffer
(insert str)
(base64-decode-region (point-min) (point-max))
(write-region-as-binary (point-min) (point-max) filename))))
;; (mel-define-method-function (encoded-text-encode-string string (nil "B"))
;; 'base64-encode-string)
(mel-define-method encoded-text-decode-string (string (nil "B"))
(if (string-match (eval-when-compile
(concat "\\`" B-encoded-text-regexp "\\'"))
string)
(base64-decode-string string)
(error "Invalid encoded-text %s" string)))
)
(mel-use-module 'mel-b-el '("base64" "B"))
(mel-use-module 'mel-q '("quoted-printable" "Q"))
(mel-use-module 'mel-g '("x-gzip64"))
(mel-use-module 'mel-u '("x-uue" "x-uuencode"))
(defvar mel-b-ccl-module
(and (featurep 'mule)
(progn
(require 'path-util)
(module-installed-p 'mel-b-ccl))))
(defvar mel-q-ccl-module
(and (featurep 'mule)
(progn
(require 'path-util)
(module-installed-p 'mel-q-ccl))))
(when mel-b-ccl-module
(mel-use-module 'mel-b-ccl '("base64" "B")))
(when mel-q-ccl-module
(mel-use-module 'mel-q-ccl '("quoted-printable" "Q")))
(when base64-dl-module
(mel-use-module 'mel-b-dl '("base64" "B")))
;;; @ region
;;;
;;;###autoload
(defun mime-encode-region (start end encoding)
"Encode region START to END of current buffer using ENCODING.
ENCODING must be string."
(interactive
(list (region-beginning)(region-end)
(completing-read "Encoding: "
(mime-encoding-alist)
nil t "base64")))
(funcall (mel-find-function 'mime-encode-region encoding) start end))
;;;###autoload
(defun mime-decode-region (start end encoding)
"Decode region START to END of current buffer using ENCODING.
ENCODING must be string."
(interactive
(list (region-beginning)(region-end)
(completing-read "Encoding: "
(mime-encoding-alist 'mime-decode-region)
nil t "base64")))
(funcall (mel-find-function 'mime-decode-region encoding)
start end))
;;; @ string
;;;
;;;###autoload
(defun mime-decode-string (string encoding)
"Decode STRING using ENCODING.
ENCODING must be string. If ENCODING is found in
`mime-string-decoding-method-alist' as its key, this function decodes
the STRING by its value."
(let ((f (mel-find-function 'mime-decode-string encoding)))
(if f
(funcall f string)
string)))
(mel-define-service encoded-text-encode-string)
(defun encoded-text-encode-string (string encoding &optional mode)
"Encode STRING as encoded-text using ENCODING.
ENCODING must be string.
Optional argument MODE allows `text', `comment', `phrase' or nil.
Default value is `phrase'."
(if (string= encoding "B")
(base64-encode-string string 'no-line-break)
(let ((f (mel-find-function 'encoded-text-encode-string encoding)))
(if f
(funcall f string mode)
string))))
(mel-define-service encoded-text-decode-string (string encoding)
"Decode STRING as encoded-text using ENCODING. ENCODING must be string.")
(defun base64-encoded-length (string)
(* (/ (+ (length string) 2) 3) 4))
(defsubst Q-encoding-printable-char-p (chr mode)
(and (not (memq chr '(?= ?? ?_)))
(<= ?\ chr)(<= chr ?~)
(cond ((eq mode 'text) t)
((eq mode 'comment)
(not (memq chr '(?\( ?\) ?\\))))
(t
(string-match "[A-Za-z0-9!*+/=_---]" (char-to-string chr))))))
(defun Q-encoded-text-length (string &optional mode)
(let ((l 0)(i 0)(len (length string)) chr)
(while (< i len)
(setq chr (aref string i))
(if (or (Q-encoding-printable-char-p chr mode)
(eq chr ? ))
(setq l (+ l 1))
(setq l (+ l 3)))
(setq i (+ i 1)))
l))
;;; @ file
;;;
;;;###autoload
(defun mime-insert-encoded-file (filename encoding)
"Insert file FILENAME encoded by ENCODING format."
(interactive
(list (read-file-name "Insert encoded file: ")
(completing-read "Encoding: "
(mime-encoding-alist)
nil t "base64")))
(funcall (mel-find-function 'mime-insert-encoded-file encoding)
filename))
;;;###autoload
(defun mime-write-decoded-region (start end filename encoding)
"Decode and write current region encoded by ENCODING into FILENAME.
START and END are buffer positions."
(interactive
(list (region-beginning)(region-end)
(read-file-name "Write decoded region to file: ")
(completing-read "Encoding: "
(mime-encoding-alist 'mime-write-decoded-region)
nil t "base64")))
(funcall (mel-find-function 'mime-write-decoded-region encoding)
start end filename))
;;; @ end
;;;
(provide 'mel)
;;; mel.el ends here.