xref: /linux/Documentation/admin-guide/vga-softcursor.rst (revision c532de5a67a70f8533d495f8f2aaa9a0491c3ad0)
1Software cursor for VGA
2=======================
3
4by Pavel Machek <pavel@atrey.karlin.mff.cuni.cz>
5and Martin Mares <mj@atrey.karlin.mff.cuni.cz>
6
7Linux now has some ability to manipulate cursor appearance.  Normally,
8you can set the size of hardware cursor.  You can now play a few new
9tricks: you can make your cursor look like a non-blinking red block,
10make it inverse background of the character it's over or to highlight
11that character and still choose whether the original hardware cursor
12should remain visible or not.  There may be other things I have never
13thought of.
14
15The cursor appearance is controlled by a ``<ESC>[?1;2;3c`` escape sequence
16where 1, 2 and 3 are parameters described below. If you omit any of them,
17they will default to zeroes.
18
19first Parameter
20	specifies cursor size::
21
22		0=default
23		1=invisible
24		2=underline,
25		...
26		8=full block
27		+ 16 if you want the software cursor to be applied
28		+ 32 if you want to always change the background color
29		+ 64 if you dislike having the background the same as the
30		     foreground.
31
32	Highlights are ignored for the last two flags.
33
34second parameter
35	selects character attribute bits you want to change
36	(by simply XORing them with the value of this parameter). On standard
37	VGA, the high four bits specify background and the low four the
38	foreground. In both groups, low three bits set color (as in normal
39	color codes used by the console) and the most significant one turns
40	on highlight (or sometimes blinking -- it depends on the configuration
41	of your VGA).
42
43third parameter
44	consists of character attribute bits you want to set.
45
46	Bit setting takes place before bit toggling, so you can simply clear a
47	bit by including it in both the set mask and the toggle mask.
48
49Examples
50--------
51
52To get normal blinking underline, use::
53
54	echo -e '\033[?2c'
55
56To get blinking block, use::
57
58	echo -e '\033[?6c'
59
60To get red non-blinking block, use::
61
62	echo -e '\033[?17;0;64c'
63