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fc68affa ER |
1 | ;;; flow-ctrl.el --- help for lusers on cu(1) or ttys with wired-in ^S/^Q flow control |
2 | ||
d733c5ec | 3 | ;;; Copyright (C) 1990, 1991, 1994 Free Software Foundation, Inc. |
3a801d0c | 4 | |
fc68affa ER |
5 | ;; Author Kevin Gallagher |
6 | ;; Maintainer: FSF | |
fc68affa | 7 | ;; Adapted-By: ESR |
fd7fa35a | 8 | ;; Keywords: hardware |
1a06eabd | 9 | |
59243403 RS |
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 | |
24 | ;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. | |
fc68affa ER |
25 | |
26 | ;;; Commentary: | |
0f39230e JB |
27 | |
28 | ;;;; Terminals that use XON/XOFF flow control can cause problems with | |
282d89c0 | 29 | ;;;; GNU Emacs users. This file contains Emacs Lisp code that makes it |
0f39230e JB |
30 | ;;;; easy for a user to deal with this problem, when using such a |
31 | ;;;; terminal. | |
32 | ;;;; | |
33 | ;;;; To invoke these adjustments, a user need only invoke the function | |
61251338 | 34 | ;;;; enable-flow-control-on with a list of terminal types in his/her own |
0f39230e JB |
35 | ;;;; .emacs file. As arguments, give it the names of one or more terminal |
36 | ;;;; types in use by that user which require flow control adjustments. | |
37 | ;;;; Here's an example: | |
38 | ;;;; | |
61251338 | 39 | ;;;; (enable-flow-control-on "vt200" "vt300" "vt101" "vt131") |
0f39230e JB |
40 | |
41 | ;;; Portability note: This uses (getenv "TERM"), and therefore probably | |
42 | ;;; won't work outside of UNIX-like environments. | |
43 | ||
fc68affa ER |
44 | ;;; Code: |
45 | ||
162de182 RS |
46 | (defvar flow-control-c-s-replacement ?\034 |
47 | "Character that replaces C-s, when flow control handling is enabled.") | |
48 | (defvar flow-control-c-q-replacement ?\036 | |
49 | "Character that replaces C-q, when flow control handling is enabled.") | |
0f39230e | 50 | |
162de182 RS |
51 | ;;;###autoload |
52 | (defun enable-flow-control (&optional argument) | |
53 | "Toggle flow control handling. | |
54 | When handling is enabled, user can type C-s as C-\\, and C-q as C-^. | |
55 | With arg, enable flow control mode if arg is positive, otherwise disable." | |
56 | (interactive "P") | |
57 | (if (if argument | |
58 | ;; Argument means enable if arg is positive. | |
59 | (<= (prefix-numeric-value argument) 0) | |
60 | ;; No arg means toggle. | |
61 | (nth 1 (current-input-mode))) | |
62 | (progn | |
63 | ;; Turn flow control off, and stop exchanging chars. | |
64 | (set-input-mode t nil (nth 2 (current-input-mode))) | |
65 | (aset keyboard-translate-table flow-control-c-s-replacement nil) | |
66 | (aset keyboard-translate-table ?\^s nil) | |
67 | (aset keyboard-translate-table flow-control-c-q-replacement nil) | |
68 | (aset keyboard-translate-table ?\^q nil)) | |
69 | ;; Turn flow control on. | |
70 | ;; Tell emacs to pass C-s and C-q to OS. | |
71 | (set-input-mode nil t (nth 2 (current-input-mode))) | |
72 | ;; Initialize translate table, saving previous mappings, if any. | |
73 | (let ((the-table (make-string 128 0))) | |
74 | (let ((i 0) | |
75 | (j (length keyboard-translate-table))) | |
76 | (while (< i j) | |
77 | (aset the-table i (elt keyboard-translate-table i)) | |
78 | (setq i (1+ i))) | |
79 | (while (< i 128) | |
80 | (aset the-table i i) | |
81 | (setq i (1+ i)))) | |
82 | (setq keyboard-translate-table the-table)) | |
83 | ;; Swap C-s and C-\ | |
84 | (aset keyboard-translate-table flow-control-c-s-replacement ?\^s) | |
85 | (aset keyboard-translate-table ?\^s flow-control-c-s-replacement) | |
86 | ;; Swap C-q and C-^ | |
87 | (aset keyboard-translate-table flow-control-c-q-replacement ?\^q) | |
88 | (aset keyboard-translate-table ?\^q flow-control-c-q-replacement) | |
89 | (message (concat | |
90 | "XON/XOFF adjustment for " | |
91 | (getenv "TERM") | |
92 | ": use C-\\ for C-s and use C-^ for C-q.")) | |
93 | (sleep-for 2))) ; Give user a chance to see message. | |
0f39230e JB |
94 | |
95 | ;;;###autoload | |
61251338 | 96 | (defun enable-flow-control-on (&rest losing-terminal-types) |
9c50f912 | 97 | "Enable flow control if using one of a specified set of terminal types. |
61251338 | 98 | Use `(enable-flow-control-on \"vt100\" \"h19\")' to enable flow control |
9c50f912 | 99 | on VT-100 and H19 terminals. When flow control is enabled, |
328561fc | 100 | you must type C-\\ to get the effect of a C-s, and type C-^ |
9c50f912 | 101 | to get the effect of a C-q." |
0f39230e JB |
102 | (let ((term (getenv "TERM")) |
103 | hyphend) | |
3bf5f17a RS |
104 | (if term |
105 | (progn | |
106 | ;; Strip off hyphen and what follows | |
107 | (while (setq hyphend (string-match "[-_][^-_]+$" term)) | |
108 | (setq term (substring term 0 hyphend))) | |
109 | (and (member term losing-terminal-types) | |
110 | (enable-flow-control)))))) | |
0f39230e | 111 | |
49116ac0 JB |
112 | (provide 'flow-ctrl) |
113 | ||
1a06eabd | 114 | ;;; flow-ctrl.el ends here |