1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
|
;;; flow-ctrl.el --- help for lusers on cu(1) or ttys with wired-in ^S/^Q flow control
;;; Copyright (C) 1990, 1991, 1994 Free Software Foundation, Inc.
;; Author Kevin Gallagher
;; Maintainer: FSF
;; Adapted-By: ESR
;; Keywords: hardware
;; 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, 675 Mass Ave, Cambridge, MA 02139, USA.
;;; Commentary:
;;;; Terminals that use XON/XOFF flow control can cause problems with
;;;; GNU Emacs users. This file contains Emacs Lisp code that makes it
;;;; easy for a user to deal with this problem, when using such a
;;;; terminal.
;;;;
;;;; To invoke these adjustments, a user need only invoke the function
;;;; enable-flow-control-on with a list of terminal types in his/her own
;;;; .emacs file. As arguments, give it the names of one or more terminal
;;;; types in use by that user which require flow control adjustments.
;;;; Here's an example:
;;;;
;;;; (enable-flow-control-on "vt200" "vt300" "vt101" "vt131")
;;; Portability note: This uses (getenv "TERM"), and therefore probably
;;; won't work outside of UNIX-like environments.
;;; Code:
(defvar flow-control-c-s-replacement ?\034
"Character that replaces C-s, when flow control handling is enabled.")
(defvar flow-control-c-q-replacement ?\036
"Character that replaces C-q, when flow control handling is enabled.")
;;;###autoload
(defun enable-flow-control (&optional argument)
"Toggle flow control handling.
When handling is enabled, user can type C-s as C-\\, and C-q as C-^.
With arg, enable flow control mode if arg is positive, otherwise disable."
(interactive "P")
(if (if argument
;; Argument means enable if arg is positive.
(<= (prefix-numeric-value argument) 0)
;; No arg means toggle.
(nth 1 (current-input-mode)))
(progn
;; Turn flow control off, and stop exchanging chars.
(set-input-mode t nil (nth 2 (current-input-mode)))
(if keyboard-translate-table
(progn
(aset keyboard-translate-table flow-control-c-s-replacement
flow-control-c-s-replacement)
(aset keyboard-translate-table ?\^s ?\^s)
(aset keyboard-translate-table flow-control-c-q-replacement
flow-control-c-q-replacement)
(aset keyboard-translate-table ?\^q ?\^q))))
;; Turn flow control on.
;; Tell emacs to pass C-s and C-q to OS.
(set-input-mode nil t (nth 2 (current-input-mode)))
;; Initialize translate table, saving previous mappings, if any.
(let ((the-table (make-string (max 128 (length keyboard-translate-table))
0)))
(let ((i 0)
(j (length keyboard-translate-table)))
(while (< i j)
(aset the-table i (elt keyboard-translate-table i))
(setq i (1+ i)))
(while (< i 128)
(aset the-table i i)
(setq i (1+ i))))
(setq keyboard-translate-table the-table))
;; Swap C-s and C-\
(aset keyboard-translate-table flow-control-c-s-replacement ?\^s)
(aset keyboard-translate-table ?\^s flow-control-c-s-replacement)
;; Swap C-q and C-^
(aset keyboard-translate-table flow-control-c-q-replacement ?\^q)
(aset keyboard-translate-table ?\^q flow-control-c-q-replacement)
(message (concat
"XON/XOFF adjustment for "
(getenv "TERM")
": use C-\\ for C-s and use C-^ for C-q."))
(sleep-for 2))) ; Give user a chance to see message.
;;;###autoload
(defun enable-flow-control-on (&rest losing-terminal-types)
"Enable flow control if using one of a specified set of terminal types.
Use `(enable-flow-control-on \"vt100\" \"h19\")' to enable flow control
on VT-100 and H19 terminals. When flow control is enabled,
you must type C-\\ to get the effect of a C-s, and type C-^
to get the effect of a C-q."
(let ((term (getenv "TERM"))
hyphend)
(if term
(progn
;; Strip off hyphen and what follows
(while (setq hyphend (string-match "[-_][^-_]+$" term))
(setq term (substring term 0 hyphend)))
(and (member term losing-terminal-types)
(enable-flow-control))))))
(provide 'flow-ctrl)
;;; flow-ctrl.el ends here
|
