/[emacs]/emacs/lisp/gnus/hex-util.el
ViewVC logotype

Diff of /emacs/lisp/gnus/hex-util.el

Parent Directory Parent Directory | Revision Log Revision Log | View Patch Patch

revision 1.1 by schwab, Thu Jul 22 16:45:49 2004 UTC revision 1.2 by miles, Sat Sep 4 13:13:43 2004 UTC
# Line 0  Line 1 
1    ;;; hex-util.el --- Functions to encode/decode hexadecimal string.
2    
3    ;; Copyright (C) 1999, 2001  Free Software Foundation, Inc.
4    
5    ;; Author: Shuhei KOBAYASHI <shuhei@aqua.ocn.ne.jp>
6    ;; Keywords: data
7    
8    ;; This file is part of FLIM (Faithful Library about Internet Message).
9    
10    ;; This program is free software; you can redistribute it and/or
11    ;; modify it under the terms of the GNU General Public License as
12    ;; published by the Free Software Foundation; either version 2, or
13    ;; (at your option) any later version.
14    
15    ;; This program 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.
19    
20    ;; You should have received a copy of the GNU General Public License
21    ;; along with this program; see the file COPYING.  If not, write to
22    ;; the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
23    ;; Boston, MA 02111-1307, USA.
24    
25    ;;; Commentary:
26    
27    ;;; Code:
28    
29    (eval-when-compile
30      (defmacro hex-char-to-num (chr)
31        (` (let ((chr (, chr)))
32             (cond
33              ((and (<= ?a chr)(<= chr ?f)) (+ (- chr ?a) 10))
34              ((and (<= ?A chr)(<= chr ?F)) (+ (- chr ?A) 10))
35              ((and (<= ?0 chr)(<= chr ?9)) (- chr ?0))
36              (t (error "Invalid hexadecimal digit `%c'" chr))))))
37      (defmacro num-to-hex-char (num)
38        (` (aref "0123456789abcdef" (, num)))))
39    
40    (defun decode-hex-string (string)
41      "Decode hexadecimal STRING to octet string."
42      (let* ((len (length string))
43             (dst (make-string (/ len 2) 0))
44             (idx 0)(pos 0))
45        (while (< pos len)
46    ;;; logior and lsh are not byte-coded.
47    ;;;  (aset dst idx (logior (lsh (hex-char-to-num (aref string pos)) 4)
48    ;;;                         (hex-char-to-num (aref string (1+ pos)))))
49          (aset dst idx (+ (* (hex-char-to-num (aref string pos)) 16)
50                           (hex-char-to-num (aref string (1+ pos)))))
51          (setq idx (1+ idx)
52                pos (+ 2 pos)))
53        dst))
54    
55    (defun encode-hex-string (string)
56      "Encode octet STRING to hexadecimal string."
57      (let* ((len (length string))
58             (dst (make-string (* len 2) 0))
59             (idx 0)(pos 0))
60        (while (< pos len)
61    ;;; logand and lsh are not byte-coded.
62    ;;;  (aset dst idx (num-to-hex-char (logand (lsh (aref string pos) -4) 15)))
63          (aset dst idx (num-to-hex-char (/ (aref string pos) 16)))
64          (setq idx (1+ idx))
65    ;;;  (aset dst idx (num-to-hex-char (logand (aref string pos) 15)))
66          (aset dst idx (num-to-hex-char (% (aref string pos) 16)))
67          (setq idx (1+ idx)
68                pos (1+ pos)))
69        dst))
70    
71    (provide 'hex-util)
72    
73    ;;; arch-tag: fe8aaa79-6c86-400e-813f-5a8cc4cb3859
74    ;;; hex-util.el ends here

Legend:
Removed from v.1.1  
changed lines
  Added in v.1.2

savannah-hackers-public@gnu.org
ViewVC Help
Powered by ViewVC 1.1.26