1;;; -*- coding: iso-2022-7bit; -*-
2;;; tramp-uu.el --- uuencode in Lisp
3
4;; Copyright (C) 2002, 2003, 2004, 2005, 2006, 2007 Free Software Foundation, Inc.
5
6;; Author: Kai Gro,A_(Bjohann <kai.grossjohann@gmx.net>
7;; Keywords: comm, terminals
8
9;; This file is free software; you can redistribute it and/or modify
10;; it under the terms of the GNU General Public License as published by
11;; the Free Software Foundation; either version 2, or (at your option)
12;; any later version.
13
14;; This file is distributed in the hope that it will be useful,
15;; but WITHOUT ANY WARRANTY; without even the implied warranty of
16;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17;; GNU General Public License for more details.
18
19;; You should have received a copy of the GNU General Public License
20;; along with GNU Emacs; see the file COPYING.  If not, write to
21;; the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
22;; Boston, MA 02110-1301, USA.
23
24;;; Commentary:
25
26;; An implementation of "uuencode" in Lisp.  Uses the function
27;; base64-encode-region which is built-in to modern Emacsen.
28
29;;; Code:
30
31(defvar tramp-uu-b64-alphabet
32  "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"
33  "Mapping from base64-encoded character to the byte it represents.")
34
35(defvar tramp-uu-b64-char-to-byte
36  (let ((i 0))
37    (mapcar (lambda (c)
38	      (prog1
39		  (cons c i)
40		(setq i (1+ i))))
41	    tramp-uu-b64-alphabet))
42  "Alist of mapping from base64 character to its byte.")
43
44(defun tramp-uu-byte-to-uu-char (byte)
45  "Return the character encoding BYTE."
46  (if (zerop byte) ?` (+ byte 32)))
47
48(defun tramp-uu-b64-char-to-byte (char)
49  "Return the byte that is encoded as CHAR."
50  (cdr (assq char tramp-uu-b64-char-to-byte)))
51
52(defun tramp-uuencode-region (beg end)
53  "UU-encode the region between BEG and END."
54  ;; First we base64 encode the region, then we transmogrify that into
55  ;; uu encoding.
56  (let ((len (base64-encode-region beg end t))
57	(padding 0)
58	i c)
59    (save-excursion
60      (goto-char beg)
61      (setq i 0)
62      (while (< i len)
63	(setq c (char-after (point)))
64	(delete-char 1)
65	(if (equal c ?=)
66	    ;; "=" means padding.  Insert "`" instead.  Not counted for length.
67	    (progn (insert "`") (setq len (1- len)))
68	  (insert (tramp-uu-byte-to-uu-char (tramp-uu-b64-char-to-byte c)))
69	  (setq i (1+ i)))
70	;; Every 60 characters, add "M" at beginning of line (as
71	;; length byte) and insert a newline.
72	(when (zerop (% i 60))
73	  (save-excursion
74	    (beginning-of-line)
75	    (insert (char-to-string (+ 32 (/ (* 3 60) 4)))))
76	  (insert "\n")))
77      ;; If there is something leftover, we compute the length byte
78      ;; for that stuff and insert it and a trailing newline.
79      (unless (zerop (% i 60))
80	(save-excursion
81	  (beginning-of-line)
82	  (insert (char-to-string (+ 32 (% (- end beg) 45)))))
83	(insert "\n"))
84      ;; Why is there always a "`" line at the end?
85      (insert "`\nend\n")
86      (goto-char beg)
87      (insert "begin 600 xxx\n"))))
88
89(provide 'tramp-uu)
90
91;;; arch-tag: 7153f2c6-8be5-4cd2-8c06-0fbcf5190ef6
92;;; tramp-uu.el ends here
93