VT features

NOTE: WORK IN PROGRESS

TODO

• improve table sorting:
  • sort C0/C1 in byte order
  • sort OSC in numerical order
  • sort CSI/ESC/DCS in final byte order
• references

xterm.js version: 4.3.0

Table of Contents

• General notes
• C0
• C1
• CSI
• DCS
• ESC
• OSC

General notes

This document lists xterm.js' support of terminal sequences. The sequences are grouped by their type:

• C0: single byte command (7bit control characters, byte range \x00 .. \x1f)
• C1: single byte command (8bit control characters, byte range \x80 .. \x9f)
• ESC: sequence starting with ESC (\x1b)
• CSI - Control Sequence Introducer: sequence starting with ESC [ (7bit) or CSI (\x9b 8bit)
• DCS - Device Control String: sequence starting with ESC P (7bit) or DCS (\x90 8bit)
• OSC - Operating System Command: sequence starting with ESC ] (7bit) or OSC (\x9d 8bit)

Application Program Command (APC), Privacy Message (PM) and Start of String (SOS) are recognized but not supported, any sequence of these types will be ignored. They are also not hookable by the API.

Note that the list only contains sequences implemented in xterm.js' core codebase. Missing sequences are either not supported or unstable/experimental. Furthermore addons or integrations can provide additional custom sequences.

To denote the sequences the following tables use the same abbreviations as xterm does:

• Ps: A single (usually optional) numeric parameter, composed of one or more decimal digits.
• Pm: A multiple numeric parameter composed of any number of single numeric parameters, separated by ; character(s), e.g. Ps ; Ps ; ....
• Pt: A text parameter composed of printable characters. Note that for most commands with Pt only ASCII printables are specified to work. Additionally the parser will let pass any codepoint greater than C1 as printable.

C0

Mnemonic	Name	Sequence	Short Description	Status
BEL	Bell	\a	Ring the bell. more	supported
BS	Backspace	\b	Move the cursor one position to the left.	supported
SO	Shift Out	\x0e	Switch to an alternative character set.	partly
FF	Form Feed	\f	Treated as LF.	supported
SI	Shift In	\x0f	Return to regular character set after Shift Out.	supported
LF	Line Feed	\n	Move the cursor one row down, scrolling if needed. more	supported
CR	Carriage Return	\r	Move the cursor to the beginning of the row.	supported
HT	Horizontal Tabulation	\t	Move the cursor to the next character tab stop.	supported
VT	Vertical Tabulation	\v	Treated as LF.	supported

Bell

The behavior of the bell is further customizable with ITerminalOptions.bellStyle and ITerminalOptions.bellSound.

Line Feed

Scrolling is restricted to scroll margins and will only happen on the bottom line.

C1

Mnemonic	Name	Sequence	Short Description	Status
DCS	Device Control String	\x90	Start of a DCS sequence.	supported
IND	Index	\x84	Move the cursor one line down scrolling if needed.	supported
NEL	Next Line	\x85	Move the cursor to the beginning of the next row.	supported
HTS	Horizontal Tabulation Set	\x88	Places a tab stop at the current cursor position.	supported
CSI	Control Sequence Introducer	\x9b	Start of a CSI sequence.	supported
ST	String Terminator	\x9c	Terminator used for string type sequences.	supported
OSC	Operating System Command	\x9d	Start of an OSC sequence.	supported
PM	Privacy Message	\x9e	Start of a privacy message.	supported
APC	Application Program Command	\x9f	Start of an APC sequence.	supported

CSI

Mnemonic	Name	Sequence	Short Description	Status
DCH	Delete Character	CSI Ps P	Delete Ps characters (default=1). more	supported
CUU	Cursor Up	CSI Ps A	Move cursor Ps times up (default=1). more	supported
SR	Scroll Right	CSI Ps SP A	Scroll viewport Ps times to the right. more	supported
SL	Scroll Left	CSI Ps SP @	Scroll viewport Ps times to the left. more	supported
ICH	Insert Characters	CSI Ps @	Insert Ps (blank) characters (default = 1). more	supported
SD	Scroll Down	CSI Ps T	Scroll Ps lines down (default=1).	supported
CPL	Cursor Backward	CSI Ps F	Move cursor Ps times up (default=1) and to the first column. more	supported
CUF	Cursor Forward	CSI Ps C	Move cursor Ps times forward (default=1).	supported
CUB	Cursor Backward	CSI Ps D	Move cursor Ps times backward (default=1).	supported
CUD	Cursor Down	CSI Ps B	Move cursor Ps times down (default=1). more	supported
CNL	Cursor Next Line	CSI Ps E	Move cursor Ps times down (default=1) and to the first column. more	supported
DECIC	Insert Columns	CSI Ps ' }	Insert Ps columns at cursor position. more	supported
VPR	Vertical Position Relative	CSI Ps e	Move cursor Ps times down (default=1).	supported
DA2	Secondary Device Attributes	CSI > c	Send primary device attributes.	supported
CHT	Cursor Horizontal Tabulation	CSI Ps I	Move cursor Ps times tabs forward (default=1).	supported
CBT	Cursor Backward Tabulation	CSI Ps Z	Move cursor Ps tabs backward (default=1).	supported
ED	Erase In Display	CSI Ps J	Erase various parts of the viewport. more	supported
DECSED	Selective Erase In Display	CSI ? Ps J	Currently the same as ED.	partly
EL	Erase In Line	CSI Ps K	Erase various parts of the active row. more	supported
DECSEL	Selective Erase In Line	CSI ? Ps K	Currently the same as EL.	partly
IL	Insert Line	CSI Ps L	Insert Ps blank lines at active row (default=1). more	supported
DL	Delete Line	CSI Ps M	Delete Ps lines at active row (default=1). more	supported
VPA	Vertical Position Absolute	CSI Ps d	Move cursor to Ps-th row (default=1).	supported
HPR	Horizontal Position Relative	CSI Ps a	Same as CUF.	supported
SU	Scroll Up	CSI Ps S	Scroll Ps lines up (default=1).	supported
CHA	Cursor Horizontal Absolute	CSI Ps G	Move cursor to Ps-th column of the active row (default=1).	supported
HPA	Horizontal Position Absolute	CSI Ps `	Same as CHA.	supported
CUP	Cursor Position	CSI Ps ; Ps H	Set cursor to position [Ps, Ps] (default = [1, 1]). more	supported
DA1	Primary Device Attributes	CSI c	Send primary device attributes.	supported
REP	Repeat Preceding Character	CSI Ps b	Repeat preceding character Ps times (default=1). more	supported
ECH	Erase Character	CSI Ps X	Erase Ps characters from current cursor position to the right (default=1). more	supported
SGR	Select Graphic Rendition	CSI Pm m	Set/Reset various text attributes. more	partly
SCORC	Restore Cursor	CSI u	Restore cursor position, charmap and text attributes.	partly
TBC	Tab Clear	CSI Ps g	Clear tab stops at current position (0) or all (3) (default=0). more	supported
SM	Set Mode	CSI Pm h	Set various terminal modes. more	partly
DECSET	DEC Private Set Mode	CSI ? Pm h	Set various terminal attributes. more	partly
RM	Reset Mode	CSI Pm l	Set various terminal attributes. more	partly
DECRST	DEC Private Reset Mode	CSI ? Pm l	Reset various terminal attributes. more	partly
HVP	Horizontal and Vertical Position	CSI Ps ; Ps f	Same as CUP.	supported
DSR	Device Status Report	CSI Ps n	Request cursor position (CPR) with Ps = 6.	supported
DECDSR	DEC Device Status Report	CSI ? Ps n	Only CPR is supported (same as DSR).	partly
DECSTR	Soft Terminal Reset	CSI ! p	Reset several terminal attributes to initial state. more	supported
DECSCUSR	Set Cursor Style	CSI Ps SP q	Set cursor style. more	supported
DECSTBM	Set Top and Bottom Margin	CSI Ps ; Ps r	Set top and bottom margins of the viewport [top;bottom] (default = viewport size).	supported
SCOSC	Save Cursor	CSI s	Save cursor position, charmap and text attributes.	partly
DECDC	Delete Columns	CSI Ps ' ~	Delete Ps columns at cursor position. more	supported

Delete Character

As characters are deleted, the remaining characters between the cursor and right margin move to the left. Character attributes move with the characters. The terminal adds blank characters at the right margin.

Cursor Up

If the cursor would pass the top scroll margin, it will stop there.

Scroll Right

SL moves the content of all lines within the scroll margins Ps times to the right. Content at the right margin is lost. SL has no effect outside of the scroll margins.

Scroll Left

SL moves the content of all lines within the scroll margins Ps times to the left. SL has no effect outside of the scroll margins.

Insert Characters

The ICH sequence inserts Ps blank characters. The cursor remains at the beginning of the blank characters. Text between the cursor and right margin moves to the right. Characters moved past the right margin are lost.

Cursor Backward

Same as CUU, additionally places the cursor at the first column.

Cursor Down

If the cursor would pass the bottom scroll margin, it will stop there.

Cursor Next Line

Same as CUD, additionally places the cursor at the first column.

Insert Columns

DECIC inserts Ps times blank columns at the cursor position for all lines with the scroll margins, moving content to the right. Content at the right margin is lost. DECIC has no effect outside the scrolling margins.

Erase In Display

Supported param values:

Ps	Effect
0	Erase from the cursor through the end of the viewport.
1	Erase from the beginning of the viewport through the cursor.
2	Erase complete viewport.
3	Erase scrollback.

Erase In Line

Supported param values:

Ps	Effect
0	Erase from the cursor through the end of the row.
1	Erase from the beginning of the line through the cursor.
2	Erase complete line.

Insert Line

For every inserted line at the scroll top one line at the scroll bottom gets removed. The cursor is set to the first column. IL has no effect if the cursor is outside the scroll margins.

Delete Line

For every deleted line at the scroll top one blank line at the scroll bottom gets appended. The cursor is set to the first column. DL has no effect if the cursor is outside the scroll margins.

Cursor Position

If ORIGIN mode is set, places the cursor to the absolute position within the scroll margins. If ORIGIN mode is not set, places the cursor to the absolute position within the viewport. Note that the coordinates are 1-based, thus the top left position starts at 1 ; 1.

Repeat Preceding Character

REP repeats the previous character Ps times advancing the cursor, also wrapping if DECAWM is set. REP no effect if the sequence does not follow a printable ASCII character (NOOP for any other sequence in between or NON ASCII characters).

Erase Character

ED erases Ps characters from current cursor position to the right. ED works inside or outside the scrolling margins.

Select Graphic Rendition

SGR selects one or more character attributes at the same time. Multiple params (up to 32) are applied from in order from left to right. The changed attributes are applied to all new characters received. If you move characters in the viewport by scrolling or any other means, then the attributes move with the characters. Supported param values by SGR:

Param	Meaning	Status
0	Normal (default). Resets any other preceding SGR.	supported
1	Bold. (also see options.drawBoldTextInBrightColors)	supported
2	Faint, decreased intensity.	supported
3	Italic.	supported
4	Underlined. (no support for newer underline styles)	supported
5	Slowly blinking.	unsupported
6	Rapidly blinking.	unsupported
7	Inverse. Flips foreground and background color.	supported
8	Invisible (hidden).	supported
9	Crossed-out characters.	unsupported
21	Doubly underlined.	unsupported
22	Normal (neither bold nor faint).	supported
23	No italic.	supported
24	Not underlined.	supported
25	Steady (not blinking).	supported
27	Positive (not inverse).	supported
28	Visible (not hidden).	supported
29	Not Crossed-out.	unsupported
30	Foreground color: Black.	supported
31	Foreground color: Red.	supported
32	Foreground color: Green.	supported
33	Foreground color: Yellow.	supported
34	Foreground color: Blue.	supported
35	Foreground color: Magenta.	supported
36	Foreground color: Cyan.	supported
37	Foreground color: White.	supported
38	Foreground color: Extended color (see below).	supported
39	Foreground color: Default (original).	supported
40	Background color: Black.	supported
41	Background color: Red.	supported
42	Background color: Green.	supported
43	Background color: Yellow.	supported
44	Background color: Blue.	supported
45	Background color: Magenta.	supported
46	Background color: Cyan.	supported
47	Background color: White.	supported
48	Background color: Extended color (see below).	supported
49	Background color: Default (original).	supported
90 - 97	Bright foreground color (analogous to 30 -37).	supported
100 - 107	Bright background color (analogous to 40 -47).	supported

Extended colors are supported for foreground (Ps=38) and background (Ps=48) as follows:

Ps + 1	Meaning	Status
0	Implementation defined.	unsupported
1	Transparent.	unsupported
2	RGB color, in the form Ps ; 2 ; R ; G ; B or Ps : 2 : : R : G : B.	supported
3	CMY color.	unsupported
4	CMYK color.	unsupported
5	Indexed (256 colors), in the form Ps ; 5 ; INDEX or Ps : 5 : INDEX.	supported

Tab Clear

Clearing tabstops off the active row (Ps = 2, VT100) is currently not supported.

Set Mode

Supported param values by SM:

Param	Action	Status
2	Keyboard Action Mode (KAM). Always on.	unsupported
4	Insert Mode (IRM).	supported
12	Send/receive (SRM). Always off.	unsupported
20	Automatic Newline (LNM). Always off.	unsupported

DEC Private Set Mode

Supported param values by DECSET:

param	Action	Status
1	Application Cursor Keys (DECCKM).	supported
2	Designate US-ASCII for character sets G0-G3 (DECANM).	supported
3	132 Column Mode (DECCOLM).	supported
6	Origin Mode (DECOM).	supported
7	Auto-wrap Mode (DECAWM).	supported
8	Auto-repeat Keys (DECARM). Always on.	unsupported
9	X10 xterm mouse protocol.	supported
12	Start Blinking Cursor.	supported
25	Show Cursor (DECTCEM).	supported
47	Use Alternate Screen Buffer.	supported
66	Application keypad (DECNKM).	supported
1000	X11 xterm mouse protocol.	supported
1002	Use Cell Motion Mouse Tracking.	supported
1003	Use All Motion Mouse Tracking.	supported
1004	Send FocusIn/FocusOut events	supported
1005	Enable UTF-8 Mouse Mode.	unsupported
1006	Enable SGR Mouse Mode.	supported
1015	Enable urxvt Mouse Mode.	unsupported
1047	Use Alternate Screen Buffer.	supported
1048	Save cursor as in DECSC.	supported
1049	Save cursor and switch to alternate buffer clearing it.	partly
2004	Set bracketed paste mode.	supported

Reset Mode

Supported param values by RM:

Param	Action	Status
2	Keyboard Action Mode (KAM). Always on.	unsupported
4	Replace Mode (IRM). (default)	supported
12	Send/receive (SRM). Always off.	unsupported
20	Normal Linefeed (LNM). Always off.	unsupported

DEC Private Reset Mode

Supported param values by DECRST:

param	Action	Status
1	Normal Cursor Keys (DECCKM).	supported
2	Designate VT52 mode (DECANM).	unsupported
3	80 Column Mode (DECCOLM).	broken
6	Normal Cursor Mode (DECOM).	supported
7	No Wraparound Mode (DECAWM).	supported
8	No Auto-repeat Keys (DECARM).	unsupported
9	Don't send Mouse X & Y on button press.	supported
12	Stop Blinking Cursor.	supported
25	Hide Cursor (DECTCEM).	supported
47	Use Normal Screen Buffer.	supported
66	Numeric keypad (DECNKM).	supported
1000	Don't send Mouse reports.	supported
1002	Don't use Cell Motion Mouse Tracking.	supported
1003	Don't use All Motion Mouse Tracking.	supported
1004	Don't send FocusIn/FocusOut events.	supported
1005	Disable UTF-8 Mouse Mode.	unsupported
1006	Disable SGR Mouse Mode.	supported
1015	Disable urxvt Mouse Mode.	unsupported
1047	Use Normal Screen Buffer (clearing screen if in alt).	supported
1048	Restore cursor as in DECRC.	supported
1049	Use Normal Screen Buffer and restore cursor.	supported
2004	Reset bracketed paste mode.	supported

Soft Terminal Reset

There are two terminal reset sequences - RIS and DECSTR. While RIS performs almost a full terminal bootstrap, DECSTR only resets certain attributes. For most needs DECSTR should be sufficient. Attributes reset to default values:

• cursor is reset (default = visible, home position)
• IRM is reset (dafault = false)
• scroll margins are reset (default = viewport size)
• erase attributes are reset to default
• charsets are reset

Set Cursor Style

Supported cursor styles:

• empty, 0 or 1: steady block
• 2: blink block
• 3: steady underline
• 4: blink underline
• 5: steady bar
• 6: blink bar

Delete Columns

DECDC deletes Ps times columns at the cursor position for all lines with the scroll margins, moving content to the left. Blank columns are added at the right margin. DECDC has no effect outside the scrolling margins.

DCS

Mnemonic	Name	Sequence	Short Description	Status
SIXEL	SIXEL Graphics	DCS Ps ; Ps ; Ps ; q Pt ST	Draw SIXEL image starting at cursor position.	unsupported
DECRQSS	Request Selection or Setting	DCS $ q Pt ST	Request several terminal settings. more	partly
DECUDK	User Defined Keys	`DCS Ps ; Ps	Pt ST`	Definitions for user-defined keys.
XTGETTCAP	Request Terminfo String	DCS + q Pt ST	Request Terminfo String.	unsupported
XTSETTCAP	Set Terminfo Data	DCS + p Pt ST	Set Terminfo Data.	unsupported

Request Selection or Setting

Response is in the form ESC P 1 $ r Pt ST for valid requests, where Pt contains the corresponding CSI string, ESC P 0 ST for invalid requests.
Supported requests and responses:

Type	Request	Response (Pt)
Graphic Rendition (SGR)	DCS $ q m ST	always reporting 0m (currently broken)
Top and Bottom Margins (DECSTBM)	DCS $ q r ST	Ptop ; Pbottom r
Cursor Style (DECSCUSR)	DCS $ q SP q ST	Pstyle SP q
Protection Attribute (DECSCA)	DCS $ q " q ST	always reporting 0 " q (DECSCA is unsupported)
Conformance Level (DECSCL)	DCS $ q " p ST	always reporting 61 ; 1 " p (DECSCL is unsupported)

ESC

Mnemonic	Name	Sequence	Short Description	Status
SC	Save Cursor	ESC 7	Save cursor position, charmap and text attributes.	supported
DECALN	Screen Alignment Pattern	ESC # 8	Fill viewport with a test pattern (E).	supported
RC	Restore Cursor	ESC 8	Restore cursor position, charmap and text attributes.	supported
IND	Index	ESC D	Move the cursor one line down scrolling if needed.	supported
NEL	Next Line	ESC E	Move the cursor to the beginning of the next row.	supported
HTS	Horizontal Tabulation Set	ESC H	Places a tab stop at the current cursor position.	supported
IR	Reverse Index	ESC M	Move the cursor one line up scrolling if needed.	supported
DCS	Device Control String	ESC P	Start of a DCS sequence.	supported
CSI	Control Sequence Introducer	ESC [	Start of a CSI sequence.	supported
ST	String Terminator	ESC \	Terminator used for string type sequences.	supported
OSC	Operating System Command	ESC ]	Start of an OSC sequence.	supported
PM	Privacy Message	ESC ^	Start of a privacy message.	supported
APC	Application Program Command	ESC _	Start of an APC sequence.	supported

OSC

Identifier	Sequence	Short Description	Status
1	OSC 1 ; Pt BEL	Set icon name.	unsupported
0	OSC 0 ; Pt BEL	Set window title and icon name. more	partly
2	OSC 2 ; Pt BEL	Set window title. more	supported

Set Windows Title and Icon Name

Icon name is not supported. For Window Title see below.

Set Windows Title

xterm.js does not manipulate the title directly, instead exposes changes via the event Terminal.onTitleChange.