CSC231 Ansi Sequences
--D. Thiebaut 13:10, 10 December 2008 (UTC)
Ansi sequences can be used to control the behavior of the program with the text screen. It allows for (crude) animation using text.
The following function illustrates how to clear the screen and position the cursor at position 1,1 (top left):
;;; ------------------------------------------------------
;;; clrScreen: clears the screen and brings the cursor
;;; to "home" position. This is done by using ANSI sequences
;;; that, when sent to the screen, do not actually print
;;; anything, but instead modify different things, such as
;;; the position of the cursor, the contents of the screen,
;;; or other screen-related properties. All ansi sequences
;;; start with Ascii 27, which is the ESCape character.
;;; ------------------------------------------------------
section .data
home db 27,"[2J" ; clear the screen
db 27,"[1;1H" ; ansi sequence to bring
; cursor at position 1,1
homeLen equ $-home
section .text
clrScreen:
pushad ; save all registers
mov eax,WRITE ; already defined
mov ebx,STDOUT ; already defined
lea ecx,[home]
mov edx,homeLen
int 0x80
popad ; restore all registers
ret
Ansi Sequences
The following list of Ansi sequences was taken from http://isthe.com/chongo/tech/comp/ansi_escapes.html
Wherever you see '#', that should be replaced by the appropriate number.
ESC code sequence Function
------------------- ---------------------------
Cursor Controls:
ESC[#;#H or ESC[#;#f Moves cusor to line #, column #
ESC[#A Moves cursor up # lines
ESC[#B Moves cursor down # lines
ESC[#C Moves cursor forward # spaces
ESC[#D Moves cursor back # spaces
ESC[#;#R Reports current cursor line & column
ESC[s Saves cursor position for recall later
ESC[u Return to saved cursor position
Erase Functions:
ESC[2J Clear screen and home cursor
ESC[K Clear to end of line
Set Graphics Rendition:
ESC[#;#;....;#m Set display attributes where # is
00 for normal display (or just 0)
01 for bold on (or just 1)
02 faint (or just 2)
03 standout (or just 3)
04 underline (or just 4)
05 blink on (or just 5)
07 reverse video on (or just 7)
08 nondisplayed (invisible) (or just 8)
22 normal
23 no-standout
24 no-underline
25 no-blink
27 no-reverse
30 black foreground
31 red foreground
32 green foreground
33 yellow foreground
34 blue foreground
35 magenta foreground
36 cyan foreground
37 white foreground
39 default foreground
40 black background
41 red background
42 green background
43 yellow background
44 blue background
45 magenta background
46 cyan background
47 white background
49 default background
ESC[=#;7h or Put screen in indicated mode where # is
ESC[=h or 0 for 40 x 25 black & white
ESC[=0h or 1 for 40 x 25 color
ESC[?7h 2 for 80 x 25 b&w
3 for 80 x 25 color
4 for 320 x 200 color graphics
5 for 320 x 200 b & w graphics
6 for 640 x 200 b & w graphics
7 to wrap at end of line
ESC[=#;7l or ESC[=l or Resets mode # set with above command
ESC[=0l or ESC[?7l
Keyboard Reassignments:
ESC[#;#;...p Keyboard reassignment. The first ASCII
or ESC["string"p code defines which code is to be
or ESC[#;"string";#; changed. The remaining codes define
#;"string";#p what it is to be changed to.
E.g. Reassign the Q and q keys to the A and a keys (and vice versa).
ESC [65;81p A becomes Q
ESC [97;113p a becomes q
ESC [81;65p Q becomes A
ESC [113;97p q becomes a
E.g. Reassign the F10 key to a DIR command.
ESC [0;68;"dir";13p The 0;68 is the extended ASCII code
for the F10 key and 13 is the ASCII
code for a carriage return.
Other function key codes F1=59,F2=60,F3=61,F4=62,F5=63
F6=64,F7=65,F8=66,F9=67,F10=68
