1 ;;; qp.el --- Quoted-Printable functions
3 ;; Copyright (C) 1998, 1999, 2000 Free Software Foundation, Inc.
5 ;; Author: Lars Magne Ingebrigtsen <larsi@gnus.org>
6 ;; Keywords: mail, extensions
8 ;; This file is part of GNU Emacs.
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)
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.
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.
27 ;; Functions for encoding and decoding quoted-printable text as
28 ;; defined in RFC 2045.
33 (eval-when-compile (defvar mm-use-ultra-safe-encoding
))
35 (defun quoted-printable-decode-region (from to
&optional coding-system
)
36 "Decode quoted-printable in the region between FROM and TO, per RFC 2045.
37 If CODING-SYSTEM is non-nil, decode bytes into characters with that
40 (unless (mm-coding-system-p coding-system
) ; e.g. `ascii' from Gnus
41 (setq coding-system nil
))
44 ;; RFC 2045: ``An "=" followed by two hexadecimal digits, one
45 ;; or both of which are lowercase letters in "abcdef", is
46 ;; formally illegal. A robust implementation might choose to
47 ;; recognize them as the corresponding uppercase letters.''
48 (let ((case-fold-search t
))
49 (narrow-to-region from to
)
50 ;; Do this in case we're called from Gnus, say, in a buffer
51 ;; which already contains non-ASCII characters which would
52 ;; then get doubly-decoded below.
54 (mm-encode-coding-region (point-min) (point-max) coding-system
))
55 (goto-char (point-min))
56 (while (and (skip-chars-forward "^=" to
)
58 (cond ((eq (char-after (1+ (point))) ?
\n)
60 ((looking-at "=[0-9A-F][0-9A-F]")
61 (let ((byte (string-to-int (buffer-substring (1+ (point))
69 (error "Malformed quoted-printable text")
72 (mm-decode-coding-region (point-min) (point-max) coding-system
)))))
74 (defun quoted-printable-decode-string (string &optional coding-system
)
75 "Decode the quoted-printable encoded STRING and return the result.
76 If CODING-SYSTEM is non-nil, decode the region with coding-system."
79 (quoted-printable-decode-region (point-min) (point-max) coding-system
)
82 (defun quoted-printable-encode-region (from to
&optional fold class
)
83 "Quoted-printable encode the region between FROM and TO per RFC 2045.
85 If FOLD, fold long lines at 76 characters (as required by the RFC).
86 If CLASS is non-nil, translate the characters matched by that class in
87 the form expected by `skip-chars-forward'.
89 If `mm-use-ultra-safe-encoding' is set, fold lines unconditionally and
90 encode lines starting with \"From\"."
93 ;; Avoid using 8bit characters. = is \075.
94 ;; Equivalent to "^\000-\007\013\015-\037\200-\377="
95 (setq class
"\010-\012\014\040-\074\076-\177"))
96 (if (fboundp 'string-as-multibyte
)
97 (setq class
(string-as-multibyte class
)))
100 (narrow-to-region from to
)
101 (mm-with-unibyte-current-buffer-mule4
102 ;; Fixme: what should this do in XEmacs/Mule?
103 (if (fboundp 'find-charset-region
) ; else XEmacs, non-Mule
104 (if (delq 'unknown
; Emacs 20 unibyte
105 (delq 'eight-bit-graphic
; Emacs 21
106 (delq 'eight-bit-control
108 (find-charset-region from to
)))))
109 (error "Multibyte character in QP encoding region")))
110 ;; Encode all the non-ascii and control characters.
111 (goto-char (point-min))
112 (while (and (skip-chars-forward class
)
116 (format "=%02X" (char-after))
118 ;; Encode white space at the end of lines.
119 (goto-char (point-min))
120 (while (re-search-forward "[ \t]+$" nil t
)
121 (goto-char (match-beginning 0))
125 (format "=%02X" (char-after))
127 (let ((mm-use-ultra-safe-encoding
128 (and (boundp 'mm-use-ultra-safe-encoding
)
129 mm-use-ultra-safe-encoding
)))
130 (when (or fold mm-use-ultra-safe-encoding
)
132 (let ((tab-width 1)) ; HTAB is one character.
133 (goto-char (point-min))
135 ;; In ultra-safe mode, encode "From " at the beginning
137 (when mm-use-ultra-safe-encoding
139 (if (looking-at "From ")
140 (replace-match "From=20" nil t
)
142 (replace-match "=2D" nil t
))))
144 (while (> (current-column) 76) ; tab-width must be 1.
146 (forward-char 75) ; 75 chars plus an "="
147 (search-backward "=" (- (point) 2) t
)
151 (forward-line))))))))))
153 (defun quoted-printable-encode-string (string)
154 "Encode the STRING as quoted-printable and return the result."
157 (quoted-printable-encode-region (point-min) (point-max))