1;;; telnet.el --- run a telnet session from within an Emacs buffer
2
3;; Copyright (C) 1985, 1988, 1992, 1994, 2001, 2002, 2003, 2004,
4;;   2005, 2006, 2007 Free Software Foundation, Inc.
5
6;; Author: William F. Schelter
7;; Maintainer: FSF
8;; Keywords: unix, comm
9
10;; This file is part of GNU Emacs.
11
12;; GNU Emacs is free software; you can redistribute it and/or modify
13;; it under the terms of the GNU General Public License as published by
14;; the Free Software Foundation; either version 2, or (at your option)
15;; any later version.
16
17;; GNU Emacs is distributed in the hope that it will be useful,
18;; but WITHOUT ANY WARRANTY; without even the implied warranty of
19;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
20;; GNU General Public License for more details.
21
22;; You should have received a copy of the GNU General Public License
23;; along with GNU Emacs; see the file COPYING.  If not, write to the
24;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
25;; Boston, MA 02110-1301, USA.
26
27;;; Commentary:
28
29;; This mode is intended to be used for telnet or rsh to a remote host;
30;; `telnet' and `rsh' are the two entry points.  Multiple telnet or rsh
31;; sessions are supported.
32;;
33;; Normally, input is sent to the remote telnet/rsh line-by-line, as you
34;; type RET or LFD.  C-c C-c sends a C-c to the remote immediately;
35;; C-c C-z sends C-z immediately.  C-c C-q followed by any character
36;; sends that character immediately.
37;;
38;; All RET characters are filtered out of the output coming back from the
39;; remote system.  The mode tries to do other useful translations based
40;; on what it sees coming back from the other system before the password
41;; query.  It knows about UNIX, ITS, TOPS-20 and Explorer systems.
42;;
43;; You can use the global telnet-host-properties to associate a telnet
44;; program and login name with each host you regularly telnet to.
45
46;;; Code:
47
48;; to do fix software types for lispm:
49;; to eval current expression.  Also to try to send escape keys correctly.
50;; essentially we'll want the rubout-handler off.
51
52;; filter is simplistic but should be okay for typical shell usage.
53;; needs hacking if it is going to deal with asynchronous output in a sane
54;; manner
55
56(require 'comint)
57
58(defvar telnet-host-properties ()
59  "Specify which telnet program to use for particular hosts.
60Each element has the form (HOSTNAME PROGRAM [LOGIN-NAME])
61HOSTNAME says which machine the element applies to.
62PROGRAM says which program to run, to talk to that machine.
63LOGIN-NAME, which is optional, says what to log in as on that machine.")
64
65(defvar telnet-new-line "\r")
66(defvar telnet-mode-map nil)
67(defvar telnet-prompt-pattern "^[^#$%>\n]*[#$%>] *")
68(defvar telnet-replace-c-g nil)
69(make-variable-buffer-local
70 (defvar telnet-remote-echoes t
71   "True if the telnet process will echo input."))
72(make-variable-buffer-local
73 (defvar telnet-interrupt-string "\C-c" "String sent by C-c."))
74
75(defvar telnet-count 0
76  "Number of output strings from telnet process while looking for password.")
77(make-variable-buffer-local 'telnet-count)
78
79(defvar telnet-program "telnet"
80  "Program to run to open a telnet connection.")
81
82(defvar telnet-initial-count -50
83  "Initial value of `telnet-count'.  Should be set to the negative of the
84number of terminal writes telnet will make setting up the host connection.")
85
86(defvar telnet-maximum-count 4
87  "Maximum value `telnet-count' can have.
88After this many passes, we stop looking for initial setup data.
89Should be set to the number of terminal writes telnet will make
90rejecting one login and prompting again for a username and password.")
91
92(defun telnet-interrupt-subjob ()
93  "Interrupt the program running through telnet on the remote host."
94  (interactive)
95  (process-send-string nil telnet-interrupt-string))
96
97(defun telnet-c-z ()
98  (interactive)
99  (process-send-string nil "\C-z"))
100
101(defun send-process-next-char ()
102  (interactive)
103  (process-send-string nil
104                       (char-to-string
105                        (let ((inhibit-quit t))
106                          (prog1 (read-char)
107                            (setq quit-flag nil))))))
108
109; initialization on first load.
110(if telnet-mode-map
111    nil
112  (setq telnet-mode-map (nconc (make-sparse-keymap) comint-mode-map))
113  (define-key telnet-mode-map "\C-m" 'telnet-send-input)
114;  (define-key telnet-mode-map "\C-j" 'telnet-send-input)
115  (define-key telnet-mode-map "\C-c\C-q" 'send-process-next-char)
116  (define-key telnet-mode-map "\C-c\C-c" 'telnet-interrupt-subjob)
117  (define-key telnet-mode-map "\C-c\C-z" 'telnet-c-z))
118
119;;maybe should have a flag for when have found type
120(defun telnet-check-software-type-initialize (string)
121  "Tries to put correct initializations in.  Needs work."
122  (let ((case-fold-search t))
123    (cond ((string-match "unix" string)
124	 (setq telnet-prompt-pattern comint-prompt-regexp)
125	 (setq telnet-new-line "\n"))
126	((string-match "tops-20" string) ;;maybe add telnet-replace-c-g
127	 (setq telnet-prompt-pattern  "[@>]*"))
128	((string-match "its" string)
129	 (setq telnet-prompt-pattern  "^[^*>\n]*[*>] *"))
130	((string-match "explorer" string)  ;;explorer telnet needs work
131	 (setq telnet-replace-c-g ?\n))))
132  (setq comint-prompt-regexp telnet-prompt-pattern))
133
134(defun telnet-initial-filter (proc string)
135  ;For reading up to and including password; also will get machine type.
136  (save-current-buffer
137    (set-buffer (process-buffer proc))
138    (let ((case-fold-search t))
139      (cond ((string-match "No such host" string)
140	     (kill-buffer (process-buffer proc))
141	     (error "No such host"))
142	    ((string-match "passw" string)
143	     (telnet-filter proc string)
144	     (setq telnet-count 0)
145	     (process-send-string proc (concat (comint-read-noecho "Password: " t)
146                                               telnet-new-line))
147	     (clear-this-command-keys))
148	    (t (telnet-check-software-type-initialize string)
149	       (telnet-filter proc string)
150	       (cond ((> telnet-count telnet-maximum-count)
151		      (set-process-filter proc 'telnet-filter))
152		     (t (setq telnet-count (1+ telnet-count)))))))))
153
154;; Identical to comint-simple-send, except that it sends telnet-new-line
155;; instead of "\n".
156(defun telnet-simple-send (proc string)
157  (comint-send-string proc string)
158  (if comint-input-sender-no-newline
159      (if (not (string-equal string ""))
160	  (process-send-eof))
161    (comint-send-string proc telnet-new-line)))
162
163(defun telnet-filter (proc string)
164  (save-excursion
165    (set-buffer (process-buffer proc))
166    (let* ((last-insertion (marker-position (process-mark proc)))
167	   (delta (- (point) last-insertion))
168	   (ie (and comint-last-input-end
169		    (marker-position comint-last-input-end)))
170	   (w (get-buffer-window (current-buffer)))
171	   (ws (and w (window-start w))))
172      (goto-char last-insertion)
173      (insert-before-markers string)
174      (set-marker comint-last-output-start last-insertion)
175      (set-marker (process-mark proc) (point))
176      (if ws (set-window-start w ws t))
177      (if ie (set-marker comint-last-input-end ie))
178      (while (progn (skip-chars-backward "^\C-m" last-insertion)
179		    (> (point) last-insertion))
180	(delete-region (1- (point)) (point)))
181      (goto-char (process-mark proc))
182      (and telnet-replace-c-g
183	   (subst-char-in-region last-insertion (point) ?\C-g
184				 telnet-replace-c-g t))
185      ;; If point is after the insertion place, move it
186      ;; along with the text.
187      (if (> delta 0)
188	  (goto-char (+ (process-mark proc) delta))))))
189
190(defun telnet-send-input ()
191  (interactive)
192;  (comint-send-input telnet-new-line telnet-remote-echoes)
193  (comint-send-input)
194  (if telnet-remote-echoes
195      (delete-region comint-last-input-start
196		     comint-last-input-end)))
197
198;;;###autoload (add-hook 'same-window-regexps "\\*telnet-.*\\*\\(\\|<[0-9]+>\\)")
199
200;;;###autoload
201(defun telnet (host &optional port)
202  "Open a network login connection to host named HOST (a string).
203Optional arg PORT specifies alternative port to connect to.
204Interactively, use \\[universal-argument] prefix to be prompted for port number.
205
206Communication with HOST is recorded in a buffer `*PROGRAM-HOST*'
207where PROGRAM is the telnet program being used.  This program
208is controlled by the contents of the global variable `telnet-host-properties',
209falling back on the value of the global variable `telnet-program'.
210Normally input is edited in Emacs and sent a line at a time."
211  (interactive (list (read-string "Open connection to host: ")
212		     (cond
213		      ((null current-prefix-arg) nil)
214		      ((consp current-prefix-arg) (read-string "Port: "))
215		      (t (prefix-numeric-value current-prefix-arg)))))
216  (if (and port (numberp port))
217      (setq port (int-to-string port)))
218  (let* ((comint-delimiter-argument-list '(?\  ?\t))
219	 (properties (cdr (assoc host telnet-host-properties)))
220	 (telnet-program (if properties (car properties) telnet-program))
221	 (hname (if port (concat host ":" port) host))
222         (name (concat telnet-program "-" (comint-arguments hname 0 nil) ))
223	 (buffer (get-buffer (concat "*" name "*")))
224	 (telnet-options (if (cdr properties) (cons "-l" (cdr properties))))
225	 process)
226    (if (and buffer (get-buffer-process buffer))
227	(pop-to-buffer (concat "*" name "*"))
228      (pop-to-buffer
229       (apply 'make-comint name telnet-program nil telnet-options))
230      (setq process (get-buffer-process (current-buffer)))
231      (set-process-filter process 'telnet-initial-filter)
232      ;; Don't send the `open' cmd till telnet is ready for it.
233      (accept-process-output process)
234      (erase-buffer)
235      (process-send-string process (concat "open " host
236                                           (if port " " "") (or port "")
237                                           "\n"))
238      (telnet-mode)
239      (setq comint-input-sender 'telnet-simple-send)
240      (setq telnet-count telnet-initial-count))))
241
242(put 'telnet-mode 'mode-class 'special)
243
244(define-derived-mode telnet-mode comint-mode "Telnet"
245  "This mode is for using telnet (or rsh) from a buffer to another host.
246It has most of the same commands as comint-mode.
247There is a variable ``telnet-interrupt-string'' which is the character
248sent to try to stop execution of a job on the remote host.
249Data is sent to the remote host when RET is typed."
250  (set (make-local-variable 'comint-prompt-regexp) telnet-prompt-pattern))
251
252;;;###autoload (add-hook 'same-window-regexps "\\*rsh-[^-]*\\*\\(\\|<[0-9]*>\\)")
253
254;;;###autoload
255(defun rsh (host)
256  "Open a network login connection to host named HOST (a string).
257Communication with HOST is recorded in a buffer `*rsh-HOST*'.
258Normally input is edited in Emacs and sent a line at a time."
259  (interactive "sOpen rsh connection to host: ")
260  (require 'shell)
261  (let ((name (concat "rsh-" host )))
262    (pop-to-buffer (make-comint name remote-shell-program nil host))
263    (set-process-filter (get-process name) 'telnet-initial-filter)
264    (telnet-mode)
265    (setq telnet-count -16)))
266
267(provide 'telnet)
268
269;;; arch-tag: 98218821-d04a-48b6-9058-57d0d4677a56
270;;; telnet.el ends here
271