1 ;;; vt100-led.el --- functions for LED control on VT-100 terminals & clones.
3 ;; Author: Howard Gayle
6 ;; Copyright (C) 1988 Free Software Foundation, Inc.
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
22 ;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
26 (defvar led-state
(make-vector 5 nil
)
27 "The internal state of the LEDs. Choices are nil, t, `flash.
28 Element 0 is not used.")
32 (aset led-state l
'flash
)
35 (defun led-off (&optional l
)
36 "Turn off vt100 led number L. With no argument, turn them all off."
39 (aset led-state
(prefix-numeric-value l
) nil
)
40 (fillarray led-state nil
))
49 "Update the terminal's LEDs to reflect the internal state."
50 (let ((f "\e[?0") ; String to flash.
51 (o "\e[0") ; String for steady on.
52 (l 1)) ; Current LED number.
54 (let ((s (aref led-state l
)))
57 (setq f
(concat f
";" (int-to-string l
))))
59 (setq o
(concat o
";" (int-to-string l
))))))
61 (setq o
(concat o
"q" f
"t"))
62 (send-string-to-terminal o
)))
66 ;;; vt100-led.el ends here