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 "^=")
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))
66 ;; Why backward-char???
67 ;;(unless (eq byte 61) ;; 61 is not ?= in XEmacs
71 (error "Malformed quoted-printable text")
74 (mm-decode-coding-region (point-min) (point-max) coding-system)))))
76 (defun quoted-printable-decode-string (string &optional coding-system)
77 "Decode the quoted-printable encoded STRING and return the result.
78 If CODING-SYSTEM is non-nil, decode the region with coding-system."
81 (quoted-printable-decode-region (point-min) (point-max) coding-system)
84 (defun quoted-printable-encode-region (from to &optional fold class)
85 "Quoted-printable encode the region between FROM and TO per RFC 2045.
87 If FOLD, fold long lines at 76 characters (as required by the RFC).
88 If CLASS is non-nil, translate the characters matched by that class in
89 the form expected by `skip-chars-forward'.
91 If `mm-use-ultra-safe-encoding' is set, fold lines unconditionally and
92 encode lines starting with \"From\"."
95 ;; Avoid using 8bit characters. = is \075.
96 ;; Equivalent to "^\000-\007\013\015-\037\200-\377="
97 (setq class "\010-\012\014\040-\074\076-\177"))
98 (if (fboundp 'string-as-multibyte)
99 (setq class (string-as-multibyte class)))
102 (narrow-to-region from to)
103 (mm-with-unibyte-current-buffer-mule4
104 (if (and (not (featurep 'xemacs)) ;; Don't check XEmacs Mule.
105 (fboundp 'find-charset-region))
106 (if (delq 'unknown ; Emacs 20 unibyte
107 (delq 'eight-bit-graphic ; Emacs 21
108 (delq 'eight-bit-control
110 (find-charset-region from to)))))
111 (error "Multibyte character in QP encoding region")))
112 ;; Encode all the non-ascii and control characters.
113 (goto-char (point-min))
114 (while (and (skip-chars-forward class)
118 (format "=%02X" (char-after))
120 ;; Encode white space at the end of lines.
121 (goto-char (point-min))
122 (while (re-search-forward "[ \t]+$" nil t)
123 (goto-char (match-beginning 0))
127 (format "=%02X" (char-after))
129 (let ((mm-use-ultra-safe-encoding
130 (and (boundp 'mm-use-ultra-safe-encoding)
131 mm-use-ultra-safe-encoding)))
132 (when (or fold mm-use-ultra-safe-encoding)
134 (let ((tab-width 1)) ; HTAB is one character.
135 (goto-char (point-min))
137 ;; In ultra-safe mode, encode "From " at the beginning
139 (when mm-use-ultra-safe-encoding
141 (if (looking-at "From ")
142 (replace-match "From=20" nil t)
144 (replace-match "=2D" nil t))))
146 (while (> (current-column) 76) ; tab-width must be 1.
148 (forward-char 75) ; 75 chars plus an "="
149 (search-backward "=" (- (point) 2) t)
153 (forward-line))))))))))
155 (defun quoted-printable-encode-string (string)
156 "Encode the STRING as quoted-printable and return the result."
159 (quoted-printable-encode-region (point-min) (point-max))