;;; kermit.el --- additions to shell mode for use with kermit, etc.
;; Copyright (C) 1988 Free Software Foundation, Inc.
;; Author: Jeff Norden <email@example.com>
;; Maintainer: FSF
;; Created: 15 Feb 1988
;; Keywords: comm
;; This file is part of GNU Emacs.
;; GNU Emacs is free software; you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation; either version 2, or (at your option)
;; any later version.
;; GNU Emacs is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
;; GNU General Public License for more details.
;; You should have received a copy of the GNU General Public License
;; along with GNU Emacs; see the file COPYING. If not, write to the
;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
;; Boston, MA 02111-1307, USA.
;; I'm not sure, but I think somebody asked about running kermit under shell
;; mode a while ago. Anyway, here is some code that I find useful. The result
;; is that I can log onto machines with primitive operating systems (VMS and
;; ATT system V :-), and still have the features of shell-mode available for
;; command history, etc. It's also handy to be able to run a file transfer in
;; an emacs window. The transfer is in the "background", but you can also
;; monitor or stop it easily.
;; The ^\ key is bound to a function for sending escape sequences to kermit,
;; and ^C^Q can be used to send any control characters needed thru to the
;; system you connect to. A more serious problem is that some brain-dead
;; systems will not recognize a ^J as an end-of-line character. So LFD is
;; bound to a new function which acts just like CR usually does in shell-mode,
;; but a ^M is sent as an end-of-line. Functions are also provided to swap the
;; bindings of CR and LFD. I've also included a filter which will clean out
;; any ^M's or ^@'s that get typed at you, but I don't really recommend it.
;; There doesn't seem to be an acceptably fast way to do this via emacs-lisp.
;; Invoking kermit by the command " kermit | tr -d '\015' " seems to work
;; better (on my system anyway).
;; Here's how I've been using this setup. We have several machines connected
;; thru a fairly stupid terminal switch. If I want to connect to unix system,
;; then I use the LFD key to talk to the switch, and ignore any ^M's in the
;; buffer, and do a " stty -echo nl " after I log in. Then the only real
;; difference from being in local shell-mode is that you need to type
;; ^C^Q^C to send an interrupt, and ^C^Q^Z for a stop signal, etc. (since ^C^C
;; just generates a local stop signal, which kermit ignores).
;; To connect to a VMS system, I use a shell script to invoke kermit thru the
;; tr filter, do "M-X kermit-send-cr", and then tell VMS that I'm on a
;; half-duplex terminal.
;; Some caveats:
;; 1) Kermit under shell mode is a real pain if you don't have pty's. I
;; recently discovered this on our 3b2/400. When kermit can't find a tty, it
;; assumes it is supposed to be in remote mode. So the simple command "kermit"
;; won't work in shell mode on such a system. You can get around this by using
;; the -c (connect) command line option, which means you also have to specify a
;; line and baud on the command line, as in "kermit -l /dev/tty53 -b 9600 -c".
;; However, this will cause kermit to exit when the connection is closed. So
;; in order to do a file transfer, you have to think ahead and and add -r
;; (receive) to the command line. This means that you can't use the server
;; feature. The only fix I can see is to muck around with the source code for
;; kermit, although this probably wouldn't be too hard. What is needed is an
;; option to force kermit to be local, to use stdin and stdout for interactive
;; speech, and to forget about cbreak mode.
;; Please let me know if any bugs turn up.
;; Feb 1988, Jeff Norden - firstname.lastname@example.org
(defvar kermit-esc-char "\C-\\" "*Kermit's escape char")
(defun kermit-esc ()
"For sending escape sequences to a kermit running in shell mode."
(concat kermit-esc-char (char-to-string (read-char)))))
(defun kermit-send-char ()
"Send an arbitrary character to a program in shell mode."
(define-key shell-mode-map "\C-\\" 'kermit-esc)
(define-key shell-mode-map "\C-c\C-q" 'kermit-send-char)
;; extra bindings for folks suffering form ^S/^Q braindamage:
(define-key shell-mode-map "\C-c\\" 'kermit-esc)
(defun kermit-send-input-cr ()
"Like \\[comint-send-input] but end the line with carriage-return."
(comint-send-string (get-buffer-process (current-buffer)) "\r"))
;; This is backwards of what makes sense, but ...
(define-key shell-mode-map "\n" 'kermit-send-input-cr)
(defun kermit-default-cr ()
"Make RETURN end the line with carriage-return and LFD end it with a newline.
This is useful for talking to other systems on which carriage-return
is the normal way to end a line."
(define-key shell-mode-map "\r" 'kermit-send-input-cr)
(define-key shell-mode-map "\n" 'comint-send-input))
(defun kermit-default-nl ()
"Make RETURN end the line with a newline char. This is the default state.
In this state, use LFD to send a line and end it with a carriage-return."
(define-key shell-mode-map "\n" 'kermit-send-input-cr)
(define-key shell-mode-map "\r" 'comint-send-input))
(defun kermit-clean-filter (proc str)
"Strip ^M and ^@ characters from process output."
(let ((beg (process-mark proc)))
(set-buffer (process-buffer proc))
(while (re-search-backward "[\r\C-a]+" beg t)
(defun kermit-clean-on ()
"Delete all null characters and ^M's from the kermit output.
Note that another (perhaps better) way to do this is to use the
command `kermit | tr -d '\\015''."
(set-process-filter (get-buffer-process (current-buffer))
(defun kermit-clean-off ()
"Cancel a previous kermit-clean-shell-on command."
(set-process-filter (get-buffer-process (current-buffer)) nil))
;;; kermit.el ends here