summaryrefslogtreecommitdiff
path: root/lisp/mail/metamail.el
blob: 4c6ef4bf92895407d5ba1d6bd9b84d8bd10d7af2 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
;;; metamail.el --- Metamail interface for GNU Emacs

;; Copyright (C) 1993, 1996, 2001, 2002, 2003, 2004,
;;   2005, 2006 Free Software Foundation, Inc.

;; Author: Masanobu UMEDA <umerin@mse.kyutech.ac.jp>
;; Keywords: mail, news, mime, multimedia

;; 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 2, 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; see the file COPYING.  If not, write to the
;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
;; Boston, MA 02110-1301, USA.

;;; Commentary:

;; Note: Metamail does not have all the options which are compatible with
;; the environment variables.  For that reason, metamail.el has to
;; hack the environment variables.  In addition, there is no way to
;; display all header fields without extra informative body messages
;; which are suppressed by the "-q" option.

;; The idea of using metamail to process MIME messages is from
;; gnus-mime.el by Spike <Spike@world.std.com>.

;;; Code:

(defvar rmail-current-message)
(defvar rmail-message-vector)

(defgroup metamail nil
  "Metamail interface for Emacs."
  :group 'mail
  :group 'hypermedia
  :group 'processes)

(defcustom metamail-program-name "metamail"
  "*Metamail program name."
  :type 'string
  :group 'metamail)

(defcustom metamail-mailer-name "emacs"
  "*Mailer name set to MM_MAILER environment variable."
  :type 'string
  :group 'metamail)

(defvar metamail-environment '("KEYHEADS=*" "MM_QUIET=1")
  "*Environment variables passed to `metamail'.
It must be a list of strings that have the format ENVVARNAME=VALUE.
It is not expected to be altered globally by `set' or `setq'.
Instead, change its value temporary using `let' or `let*' form.")

(defcustom metamail-switches '("-x" "-d" "-z")
  "*Switches for `metamail' program.
`-z' is required to remove zap file.
It is not expected to be altered globally by `set' or `setq'.
Instead, change its value temporary using `let' or `let*' form.
`-m MAILER' argument is automatically generated from the
`metamail-mailer-name' variable."
  :type '(repeat (string :tag "Switch"))
  :group 'metamail)

;;;###autoload
(defun metamail-interpret-header ()
  "Interpret a header part of a MIME message in current buffer.
Its body part is not interpreted at all."
  (interactive)
  (save-excursion
    (let* ((buffer-read-only nil)
	   (metamail-switches		;Inhibit processing an empty body.
	    (append metamail-switches '("-c" "text/plain" "-E" "7bit")))
	   (end (progn
		  (goto-char (point-min))
		  (search-forward "\n\n" nil 'move)
		  ;; An extra newline is inserted by metamail if there
		  ;; is no body part.  So, insert a dummy body by
		  ;; itself.
		  (insert "\n")
		  (point))))
      (metamail-region (point-min) end nil nil 'nodisplay)
      ;; Remove an extra newline inserted by myself.
      (goto-char (point-min))
      (if (search-forward "\n\n\n" nil t)
	  (delete-char -1))
      )))

;;;###autoload
(defun metamail-interpret-body (&optional viewmode nodisplay)
  "Interpret a body part of a MIME message in current buffer.
Optional argument VIEWMODE specifies the value of the
EMACS_VIEW_MODE environment variable (defaulted to 1).
Optional argument NODISPLAY non-nil means buffer is not
redisplayed as output is inserted.
Its header part is not interpreted at all."
  (interactive "p")
  (save-excursion
    (let ((contype nil)
	  (encoding nil)
	  (end (progn
		 (goto-char (point-min))
		 (search-forward "\n\n" nil t)
		 (point))))
      ;; Find Content-Type and Content-Transfer-Encoding from the header.
      (save-restriction
	(narrow-to-region (point-min) end)
	(setq contype
	      (or (mail-fetch-field "Content-Type") "text/plain"))
	(setq encoding
	      (or (mail-fetch-field "Content-Transfer-Encoding") "7bit")))
      ;; Interpret the body part only.
      (let ((metamail-switches		;Process body part only.
	     (append metamail-switches
		     (list "-b" "-c" contype "-E" encoding))))
	(metamail-region end (point-max) viewmode nil nodisplay))
      ;; Mode specific hack.
      (cond ((eq major-mode 'rmail-mode)
	     ;; Adjust the marker of this message if in Rmail mode buffer.
	     (set-marker (aref rmail-message-vector (1+ rmail-current-message))
			 (point-max))))
      )))

;;;###autoload
(defun metamail-buffer (&optional viewmode buffer nodisplay)
  "Process current buffer through `metamail'.
Optional argument VIEWMODE specifies the value of the
EMACS_VIEW_MODE environment variable (defaulted to 1).
Optional argument BUFFER specifies a buffer to be filled (nil
means current).
Optional argument NODISPLAY non-nil means buffer is not
redisplayed as output is inserted."
  (interactive "p")
  (metamail-region (point-min) (point-max) viewmode buffer nodisplay))

;;;###autoload
(defun metamail-region (beg end &optional viewmode buffer nodisplay)
  "Process current region through 'metamail'.
Optional argument VIEWMODE specifies the value of the
EMACS_VIEW_MODE environment variable (defaulted to 1).
Optional argument BUFFER specifies a buffer to be filled (nil
means current).
Optional argument NODISPLAY non-nil means buffer is not
redisplayed as output is inserted."
  (interactive "r\np")
  (let ((curbuf (current-buffer))
	(buffer-read-only nil)
	(metafile (make-temp-file "metamail"))
	(option-environment
	 (list (format "EMACS_VIEW_MODE=%d"
		       (if (numberp viewmode) viewmode 1)))))
    (save-excursion
      ;; Gee!  Metamail does not ouput to stdout if input comes from
      ;; stdin.
      (let ((selective-display nil))	;Disable ^M to nl translation.
	(write-region beg end metafile nil 'nomessage))
      (if buffer
	  (set-buffer buffer))
      (setq buffer-read-only nil)
      ;; Clear destination buffer.
      (if (eq curbuf (current-buffer))
	  (delete-region beg end)
	(delete-region (point-min) (point-max)))
      ;; We have to pass the environment variable KEYHEADS to display
      ;; all header fields.  Metamail should have an optional argument
      ;; to pass such information directly.
      (let ((process-environment
	     (append process-environment
		     metamail-environment option-environment))
	    (coding-system-for-read 'undecided))
	(apply (function call-process)
	       metamail-program-name
	       nil
	       t			;Output to current buffer
	       (not nodisplay)		;Force redisplay
	       (append metamail-switches
		       (list "-m" (or metamail-mailer-name "emacs"))
		       (list metafile))))
      ;; `metamail' may not delete the temporary file!
      (condition-case error
	  (delete-file metafile)
	(error nil))
      )))

(provide 'metamail)

;;; arch-tag: 52c0cb6f-d800-4776-9789-f0275cb5490e
;;; metamail.el ends here