ANSI ESCAPE CODE

(Redirected from ISO/IEC 6429)
'ANSI escape codes' are used to control text formatting and other output options on text terminals. In this context, 'ANSI' refers to the 'ANSI X3.64' standard (which was withdrawn in 1997). It was replaced by 'ISO/IEC 6429', and is equivalent to 'ECMA-48'.
Most of these 'escape sequences' start with the characters 'ESC' (ASCII decimal 27/hex 0x1B/octal 033) and '[' (left bracket). This sequence is called CSI for 'Control Sequence Introducer' (or Control Sequence Initiator). There is a single-character 'CSI' (155/0x9B/octal233) as well. The 'ESC'+'[' two character sequence is more often used than the single-character alternative, although terminals which support ISO 8859 recognize either sequence. Other devices, e.g., those supporting only ASCII (7-bits), or which implement 8-bit code pages which use the 0x80–0x9F control character range for other purposes will recognize only the two character sequence.

Contents

Support

Windows and DOS

Codes

Examples

See also

External links

Support

Most terminal emulators running on Unix-like systems such as Linux have support built in, as do such systems' native consoles.

Windows and DOS

Windows 95, Windows 98 and DOS systems need a device driver for the ANSI codes - the de facto standard being ANSI.SYS, but others are used as well.
Console windows in Windows versions based on NT (NT4, 2000 Professional, 2000 Server, XP, Server 2003, Vista, Server "Longhorn") do not natively support ANSI Escape sequences, though some support is possible. By adding the following line to the CONFIG.NT file located in the Windows System32 directory, ANSI output from 16-bit legacy programs executing under the NTVDM will be interpreted:
DEVICE=ANSI.SYS
Some support is also offered through alternate command processors such as JP Software's 4NT and Michael J. Mefford's ANSI.COM.
In other words, 32-bit character-mode windows applications can not write ANSI escape sequences to the console, but must interpret their actions and call the native Console API intrinsic to accomplish the proper result. Note that the window's Console API does have some restrictions regarding ''blink'', ''underline'' and ''reverse'' VGA attributes. In exchange for ''blink'', the screen allows for bright background colors. No access from user-mode is given to set the underline registers. The following attribute bits for SetConsoleTextAttribute() have no function even though they are listed:
COMMON_LVB_REVERSE_VIDEO
COMMON_LVB_UNDERSCORE
Reverse can be emulated in one's code without much difficulty.
If ANSI.SYS is loaded in MS-DOS, the escape character can be specified as $e in the ''prompt'' command, e.g. ''prompt $e[44m;...'' would specify a blue background as part of the prompt. In most modern programming languages it can be specified as "" (Perl and Ruby also offer the equivalent "e"), in Java it can be specified as "u001B", and in QBasic or GWBASIC, it can be specified as CHR$(27) or CHR$(&H1B).
Note: most devices only support a subset of the SGR (Select Graphic Rendition) codes.

Codes

The general structure of an ANSI code is CSI ''n1'' ; ''n2''... ''letter''. The numbers are optional parameters, and the final letter specifies the command. The default value used for omitted parameters varies with the command; it is usually 1 or 0.

Some ANSI codes

Code	Name	Effect
CSI ''n'' A	CUU	Moves the cursor ''n'' (default 1) cells in the given direction. If the cursor is already at the edge of the screen, this has no effect. CUU: Up; CUD: Down; CUF: Forward; CUB: Back;
CSI ''n'' B	CUD
CSI ''n'' C	CUF
CSI ''n'' D	CUB
CSI ''n'' E	CNL	Moves cursor to beginning of the line ''n'' (default 1) lines down (next line).
CSI ''n'' F	CPL	Moves cursor to beginning of the line ''n'' (default 1) lines up (previous line).
CSI ''n'' G	CHA	Moves the cursor to column ''n''.
CSI ''n'' ; ''m'' H	CUP	Moves the cursor to row ''n'', column ''m''. The values are 1-based, and default to 1 (top left corner) if omitted. A sequence such as CSI ;5H is a synonym for CSI 1;5H as well as CSI 17;H is the same as CSI 17H and CSI 17;1H
CSI ''n'' J	ED	Clears part of the screen. If ''n'' is zero (or missing), clear from cursor to end of screen. If ''n'' is one, clear from cursor to beginning of the screen. If ''n'' is two, clear entire screen (and moves cursor to upper left on MS-DOS ANSI.SYS).
CSI ''n'' K	EL	Erases part of the line. If ''n'' is zero (or missing), clear from cursor to the end of the line. If ''n'' is one, clear from cursor to beginning of the line. If ''n'' is two, clear entire line. Cursor position does not change.
CSI ''n'' S	SU	Scroll whole page up by ''n'' (default 1) lines. New lines are added at the bottom. (not ANSI.SYS)
CSI ''n'' T	SD	Scroll whole page down by ''n'' (default 1) lines. New lines are added at the top. (not ANSI.SYS)
CSI ''n'' ; ''m'' f	HVP	Moves the cursor to row ''n'', column ''m''. Both default to 1 if omitted. Same as CUP
CSI ''n'' [;''k''] m	SGR	Sets SGR (Select Graphic Rendition) parameters. After CSI can be zero or more parameters separated with ;. With no parameters, CSI m is treated as CSI 0 m (reset / normal), which is typical of most of the ANSI codes.
CSI 6 n	DSR	Reports the cursor position to the application as (as though typed at the keyboard) ESC[''n'';''m''R, where ''n'' is the row and ''m'' is the column. (May not work on MS-DOS.)
CSI s	SCP	Saves the cursor position.
CSI u	RCP	Restores the cursor position.

Color table

Intensity	0	1	2	3	4	5	6	7	9
Normal	Black	Red	Green	Yellow	Blue	Magenta	Cyan	White	reset
Bright	Black	Red	Green	Yellow	Blue	Magenta	Cyan	White

SGR (Select Graphic Rendition) parameters

Code	Effect	Note
0	Reset / Normal	all attributes off
1	Intensity: Bold
2	Intensity: Faint	not widely supported
3	Italic: on	not widely supported. Sometimes treated as inverse.
4	Underline: Single	not widely supported
5	Blink: Slow	less than 150 per minute
6	Blink: Rapid	MS-DOS ANSI.SYS; 150 per minute or more
7	Image: Negative	inverse or reverse; swap foreground and background
8	Conceal	not widely supported
21	Underline: Double
22	Intensity: Normal	not bold and not faint
24	Underline: None
25	Blink: off
27	Image: Positive
28	Reveal	conceal off
30–39	Set foreground color, normal intensity
40–49	Set background color, normal intensity
90–99	Set foreground color, high intensity	aixterm
100–109	set background color, high intensity	aixterm

Examples

CSI 0 ; 6 8 ; "DIR" ; 13 p — This re-assigns the key F10 to send to the keyboard buffer the string "DIR" and ENTER, which in the DOS command line would display the contents of the current directory. (MS-DOS ANSI.SYS only)
CSI 2 J — This clears the screen and, on some devcies, locates the cursor to the y,x position 1,1 (upper left corner).
CSI 32 m — This makes text green. On MS-DOS, normally the green would be dark, dull green, so you may wish to enable Bold with the code CSI 1 m which would make it bright green, or combined as CSI 32 ; 1 m. MS-DOS ANSI.SYS uses the Bold state to make the character Bright; also the Blink state can be set (via INT 10, AX 1003h, BL 00h) to render the Background in the Bright mode. MS-DOS ANSI.SYS does not support SGR codes 90–97 and 100–107 directly.
CSI s — This saves the cursor position. Using the code CSI u will restore it to the position. Say the current cursor position is 7(y) and 10(x). The code CSI s will save those two numbers. Now you can move to a different cursor position, such as 20(y) and 3(x), using the code CSI 20 ; 3 H or CSI 20 ; 3 f. Now if you use the code CSI u the cursor position will return to 7(y) and 10(x). Some terminals require the DEC sequences ESC 7 / ESC 8 instead.

See also

★ ANSI art

★ Control character

★ AVATAR

External links

★ Standard ECMA-48: Control Functions for Coded Character Sets ''5th edition (June 1991)''

★ ANSI Escape Code Usage Example

★ ANSI.SYS -- ansi terminal emulation escape sequences

★ ANSI/VT100 Terminal Control Escape Sequences Note: VT100's do not do color

★ ANSI CODES

★ Xterm / Escape Sequences

★ AIXterm / Escape Sequences

★ A collection of escape sequences for terminals that are vaguely compliant with ECMA-48 and friends.