1;;; vt100-led.el --- functions for LED control on VT-100 terminals & clones 2 3;; Copyright (C) 1988, 2001, 2002, 2003, 2004, 2005, 4;; 2006, 2007 Free Software Foundation, Inc. 5 6;; Author: Howard Gayle 7;; Maintainer: FSF 8;; Keywords: hardware 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;;; Code: 30 31(defvar led-state (make-vector 5 nil) 32 "The internal state of the LEDs. Choices are nil, t, `flash'. 33Element 0 is not used.") 34 35(defun led-flash (l) 36 "Flash LED l." 37 (aset led-state l 'flash) 38 (led-update)) 39 40(defun led-off (&optional l) 41 "Turn off vt100 led number L. With no argument, turn them all off." 42 (interactive "P") 43 (if l 44 (aset led-state (prefix-numeric-value l) nil) 45 (fillarray led-state nil)) 46 (led-update)) 47 48(defun led-on (l) 49 "Turn on LED L." 50 (aset led-state l t) 51 (led-update)) 52 53(defun led-update () 54 "Update the terminal's LEDs to reflect the internal state." 55 (let ((f "\e[?0") ; String to flash. 56 (o "\e[0") ; String for steady on. 57 (l 1)) ; Current LED number. 58 (while (/= l 5) 59 (let ((s (aref led-state l))) 60 (cond 61 ((eq s 'flash) 62 (setq f (concat f ";" (int-to-string l)))) 63 (s 64 (setq o (concat o ";" (int-to-string l)))))) 65 (setq l (1+ l))) 66 (setq o (concat o "q" f "t")) 67 (send-string-to-terminal o))) 68 69(provide 'vt100-led) 70 71;;; arch-tag: 346e6480-5e31-4234-aafe-257cea4a36d1 72;;; vt100-led.el ends here 73