Xterm Control Sequences

Definitions

c

The literal character c.

C

A single (required) character.

P s

A single (usually optional) numeric parameter, composed of one of more digits.

P m

A multiple numeric parameter composed of any number of single numeric parameters, separated by ; character(s). Individual values for the parameters are listed with P s .

P t

A text parameter composed of printable characters.

C1 (8-Bit) Control Characters

The xterm program recognizes both 8-bit and 7-bit control characters. It generates 7-bit controls (by default) or 8-bit if S8C1T is enabled. The following pairs of 7-bit and 8-bit control characters are equivalent:

ESC D

Index ( IND is 0x84)

ESC E

ESC H

ESC M

ESC N

ESC O

ESC P

ESC V

ESC W

ESC X

ESC Z

ESC [

ESC \

ESC ]

ESC ^

ESC _

These control characters are used in the vtXXX emulation.

VT100 Mode

Most of these control sequences are standard VT102 control sequences, but there is support for later DEC VT terminals (i.e., VT220 and VT320), as well as ISO 6429 and aixterm color controls. VT102 features not supported are auto-repeat and blinking characters. There are additional control sequences to provide xterm-dependent functions, such as the scrollbar or window size. Where the function is specified by DEC or ISO 6429, the code assigned to it is given in parentheses. The escape codes to designate and invoke character sets are specified by ISO 2022; see that document for a discussion of character sets.

Single-character functions

BEL

Bell (Ctrl-G)

BS

Backspace (Ctrl-H)

CR

Carriage Return (Ctrl-M)

ENQ

Return Terminal Status (Ctrl-E). Default response is an empty string, but may be overridden by a resource answerbackString.

FF

Form Feed or New Page (NP) (Ctrl-L) same as LF

LF

Line Feed or New Line (NL) (Ctrl-J)

SO

Shift Out (Ctrl-N) → Switch to Alternate Character Set: invokes the G1 character set.

SP

Space.

TAB

Horizontal Tab (HT) (Ctrl-I)

VT

Vertical Tab (Ctrl-K) same as LF

SI

Shift In (Ctrl-O) → Switch to Standard Character Set: invokes the G0 character set (the default).

Controls beginning with ESC (other than those where ESC is part of a 7-bit equivalent to 8-bit C1 controls), ordered by the final character(s).

ESC SP F

7-bit controls (S7C1T).

ESC SP G

8-bit controls (S8C1T).

ESC SP L

Set ANSI conformance level 1 (dpANS X3.134.1).

ESC SP M

Set ANSI conformance level 2 (dpANS X3.134.1).

ESC SP N

Set ANSI conformance level 3 (dpANS X3.134.1).

ESC # 3

DEC double-height line, top half (DECDHL)

ESC # 4

DEC double-height line, bottom half (DECDHL)

ESC # 5

DEC single-width line (DECSWL)

ESC # 6

DEC double-width line (DECDWL)

ESC # 8

DEC Screen Alignment Test (DECALN)

ESC % @

Select default character set, ISO 8859-1 (ISO 2022)

ESC % G

Select UTF-8 character set (ISO 2022)

ESC ( C

Designate G0 Character Set (ISO 2022)

ESC ) C

Designate G1 Character Set (ISO 2022)

ESC * C

Designate G2 Character Set (ISO 2022)

ESC + C

Designate G3 Character Set (ISO 2022)

Final character C for designating character sets (0 , A and B apply to VT100 and up, the remainder to VT220 and up): C = 0 → DEC Special Character and Line Drawing Set C = A → United Kingdom (UK) C = B → United States (USASCII) C = 4 → Dutch C = C or 5 → Finnish C = R → French C = Q → French Canadian C = K → German C = Y → Italian C = E or 6 → Norwegian/Danish C = Z → Spanish C = H or 7 → Swedish C = = → Swiss

Application Program-Control functions

APC P t ST

xterm implements no APC functions; P t is ignored. P t need not be printable characters.

Device-Control functions

DCS P s ; P s | P t ST

User-Defined Keys (DECUDK). The first parameter: P s = 0 → Clear all UDK definitions before starting (default) P s = 1 → Erase Below (default) The second parameter: P s = 0 → Lock the keys (default) P s = 1 → Do not lock. The third parameter is a ’;’-separated list of strings denoting the key-code separated by a ’/’ from the hex-encoded key value. The key codes correspond to the DEC function-key codes (e.g., F6=17).

Functions using CSI , ordered by the final character(s)

CSI P s @

Insert P s (Blank) Character(s) (default = 1) (ICH)

CSI P s A

Cursor Up P s Times (default = 1) (CUU)

CSI P s B

Cursor Down P s Times (default = 1) (CUD)

CSI P s C

Cursor Forward P s Times (default = 1) (CUF)

CSI P s D

Cursor Backward P s Times (default = 1) (CUB)

CSI P s E

Cursor Next Line P s Times (default = 1) (CNL)

CSI P s F

Cursor Preceding Line P s Times (default = 1) (CPL)

CSI P s G

Cursor Character Absolute [column] (default = [row,1]) (CHA)

CSI P s ; P s H

Cursor Position [row;column] (default = [1,1]) (CUP)

CSI P s I

Cursor Forward Tabulation P s tab stops (default = 1) (CHT)

CSI P s J

Erase in Display (ED) P s = 0 → Erase Below (default) P s = 1 → Erase Above P s = 2 → Erase All P s = 3 → Erase Saved Lines (xterm)

CSI ? P s J

Erase in Display (DECSED) P s = 0 → Selective Erase Below (default) P s = 1 → Selective Erase Above P s = 2 → Selective Erase All

CSI P s K

Erase in Line (EL) P s = 0 → Erase to Right (default) P s = 1 → Erase to Left P s = 2 → Erase All

CSI ? P s K

Erase in Line (DECSEL) P s = 0 → Selective Erase to Right (default) P s = 1 → Selective Erase to Left P s = 2 → Selective Erase All

CSI P s L

Insert P s Line(s) (default = 1) (IL)

CSI P s M

Delete P s Line(s) (default = 1) (DL)

CSI P s P

Delete P s Character(s) (default = 1) (DCH)

CSI P s S

Scroll up P s lines (default = 1) (SU)

CSI P s T

Scroll down P s lines (default = 1) (SD)

CSI P s ; P s ; P s ; P s ; P s T

Initiate hilite mouse tracking. Parameters are [func;startx;starty;firstrow;lastrow]. See the section Mouse Tracking.

If 16-color support is compiled, the following apply. Assume that xterm’s resources are set so that the ISO color codes are the first 8 of a set of 16. Then the aixterm colors are the bright versions of the ISO colors: P s = 9 0 → Set foreground color to Black P s = 9 1 → Set foreground color to Red P s = 9 2 → Set foreground color to Green P s = 9 3 → Set foreground color to Yellow P s = 9 4 → Set foreground color to Blue P s = 9 5 → Set foreground color to Magenta P s = 9 6 → Set foreground color to Cyan P s = 9 7 → Set foreground color to White P s = 1 0 0 → Set background color to Black P s = 1 0 1 → Set background color to Red P s = 1 0 2 → Set background color to Green P s = 1 0 3 → Set background color to Yellow P s = 1 0 4 → Set background color to Blue P s = 1 0 5 → Set background color to Magenta P s = 1 0 6 → Set background color to Cyan P s = 1 0 7 → Set background color to White

If xterm is compiled with the 16-color support disabled, it supports the following, from rxvt: P s = 1 0 0 → Set foreground and background color to default

If 88- or 256-color support is compiled, the following apply. P s = 3 8 ; 5 ; P s → Set foreground color to the second P s P s = 4 8 ; 5 ; P s → Set background color to the second P s

CSI P s n

Device Status Report (DSR) P s = 5 → Status Report CSI 0 n (‘‘OK’’) P s = 6 → Report Cursor Position (CPR) [row;column] as

CSI r ; c R

CSI P s ; P s “ p

CSI P s ; P s ; P s t

CSI P t ; P l ; P b ; P r ’ w

CSI P s ; P u ’ z

Operating System Controls

OSC P s ; P t ST

OSC P s ; P t BEL

Set Text Parameters. For colors and font, if P t is a "?", the control sequence elicits a response which consists of the control sequence which would set the corresponding value. The dtterm control sequences allow you to determine the icon name and window title. P s = 0 → Change Icon Name and Window Title to P t P s = 1 → Change Icon Name to P t P s = 2 → Change Window Title to P t P s = 3 → Set X property on top-level window. P t should be in the form "prop=value", or just "prop" to delete the property P s = 4 ; c ; spec → Change Color Number c to the color specified by spec, i.e., a name or RGB specification as per XParseColor. Any number of c name pairs may be given. The color numbers correspond to the ANSI colors 0-7, their bright versions 8-15, and if supported, the remainder of the 88-color or 256-color table. If a "?" is given rather than a name or RGB specification, xterm replies with a control sequence of the same form which can be used to set the corresponding color. Because more than one pair of color number and specification can be given in one control sequence, xterm can make more than one reply. The 8 colors which may be set using 1 0 through 1 7 are denoted dynamic colors, since the corresponding control sequences were the first means for setting xterm’s colors dynamically, i.e., after it was started. They are not the same as the ANSI colors. One or more parameters is expected for P t . Each succesive parameter changes the next color in the list. The value of P s tells the starting point in the list. The colors are specified by name or RGB specification as per XParseColor. If a "?" is given rather than a name or RGB specification, xterm replies with a control sequence of the same form which can be used to set the corresponding dynamic color. Because more than one pair of color number and specification can be given in one control sequence, xterm can make more than one reply. P s = 1 0 → Change VT100 text foreground color to P t P s = 1 1 → Change VT100 text background color to P t P s = 1 2 → Change text cursor color to P t P s = 1 3 → Change mouse foreground color to P t P s = 1 4 → Change mouse background color to P t P s = 1 5 → Change Tektronix foreground color to P t P s = 1 6 → Change Tektronix background color to P t P s = 1 7 → Change highlight color to P t P s = 4 6 → Change Log File to P t (normally disabled by a compile-time option) P s = 5 0 → Set Font to P t If P t begins with a "#", index in the font menu, relative (if the next character is a plus or minus sign) or absolute. A number is expected but not required after the sign (the default is the current entry for relative, zero for absolute indexing).

Privacy Message

PM P t ST

xterm implements no PM functions; P t is ignored. P t need not be printable characters.

PC-Style Function Keys

If xterm does minimal translation of the function keys, it usually does this with a PC-style keyboard, so PC-style function keys result. Sun keyboards are similar to PC keyboards. Both have cursor and scrolling operations printed on the keypad, which duplicate the smaller cursor and scrolling keypads.

X does not predefine NumLock (used for VT220 keyboards) or Alt (used as an extension for the Sun/PC keyboards) as modifiers. These keys are recognized as modifiers when enabled by the numLock resource, or by the DECSET 1 0 3 5 control sequence.

The cursor keys transmit the following escape sequences depending on the mode specified via the DECCKM escape sequence.

The home- and end-keys (unlike PageUp and other keys also on the 6-key editing keypad) are considered "cursor keys" by xterm. Their mode is also controlled by the DECCKM escape sequence:

The application keypad transmits the following escape sequences depending on the mode specified via the DECPNM and DECPAM escape sequences. Use the NumLock key to override the application mode.

Not all keys are present on the Sun/PC keypad (e.g., PF1, Tab), but are supported by the program.

They also provide 12 function keys, as well as a few other special-purpose keys.

Older versions of xterm implement different escape sequences for F1 through F4. These can be activated by setting the oldXtermFKeys resource. However, since they do not correspond to any hardware terminal, they have been deprecated. (The DEC VT220 reserves F1 through F5 for local functions such as Setup).

In normal mode, i.e., a Sun/PC keyboard when the sunKeyboard resource is false, xterm recognizes function key modifiers which are parameters appended before the final character of the control sequence.

For example, shift-F5 would be sent as CSI 1 5 ; 2 ~

If the alwaysUseMods resource is set, the Meta modifier also is recognized, making parameters 9 through 16.

VT220-Style Function Keys

However, xterm is most useful as a DEC VT102 or VT220 emulator. Set the sunKeyboard resource to true to force a Sun/PC keyboard to act like a VT220 keyboard.

The VT102/VT220 application keypad transmits unique escape sequences in application mode, which are distinct from the cursor and scrolling keypad:

The VT220 provides a 6-key editing keypad, which is analogous to that on the PC keyboard. It is not affected by DECCKM or DECPNM/DECPAM:

The VT220 provides 8 additional function keys. With a Sun/PC keyboard, access these keys by Control/F1 for F13, etc.

VT52-Style Function Keys

A VT52 does not have function keys, but it does have a numeric keypad and cursor keys. They differ from the other emulations by the prefix. Also, the cursor keys do not change:

The keypad is similar:

Sun-Style Function Keys

The xterm program provides support for Sun keyboards more directly, by a menu toggle that causes it to send Sun-style function key codes rather than VT220. Note, however, that the sun and VT100 emulations are not really compatible. For example, their wrap-margin behavior differs.

Only function keys are altered; keypad and cursor keys are the same. The emulation responds identically. See the xterm-sun terminfo entry for details.

HP-Style Function Keys

Similarly, xterm can be compiled to support HP keyboards. See the xterm-hp terminfo entry for details.

Mouse Tracking

The VT widget can be set to send the mouse position and other information on button presses. These modes are typically used by editors and other full-screen applications that want to make use of the mouse.

There are six mutually exclusive modes. One is DEC Locator mode, enabled by the DECELR CSI P s ; P s ´z control sequence, and is not described here (control sequences are summarized above). The remaining five modes are each enabled (or disabled) by a different parameter in DECSET CSI ? P m h or DECRST CSI ? P m l control sequence.

Manifest constants for the parameter values are defined in xcharmouse.h as follows:

                #define SET_X10_MOUSE               9
                #define SET_VT200_MOUSE             1000
                #define SET_VT200_HIGHLIGHT_MOUSE   1001
                #define SET_BTN_EVENT_MOUSE         1002
                #define SET_ANY_EVENT_MOUSE         1003

The motion reporting modes are strictly xterm extensions, and are not part of any standard, though they are analogous to the DEC VT200 DECELR locator reports.

Parameters (such as pointer position and button number) for all mouse tracking escape sequences generated by xterm encode numeric parameters in a single character as value+32. For example, ! specifies the value 1. The upper left character position on the terminal is denoted as 1,1.

X10 compatibility mode sends an escape sequence only on button press, encoding the location and the mouse button pressed. It is enabled by specifying parameter 9 to DECSET. On button press, xterm sends CSI M C b C x C y (6 characters). C b is button−1. C x and C y are the x and y coordinates of the mouse when the button was pressed.

Normal tracking mode sends an escape sequence on both button press and release. Modifier key (shift, ctrl, meta) information is also sent. It is enabled by specifying parameter 1000 to DECSET. On button press or release, xterm sends CSI M C b C x C y . The low two bits of C b encode button information: 0=MB1 pressed, 1=MB2 pressed, 2=MB3 pressed, 3=release. The next three bits encode the modifiers which were down when the button was pressed and are added together: 4=Shift, 8=Meta, 16=Control. Note however that the shift and control bits are normally unavailable because xterm uses the control modifier with mouse for popup menus, and the shift modifier is used in the default translations for button events. The Meta modifier recognized by xterm is the mod1 mask, and is not necessarily the "Meta" key (see xmodmap). C x and C y are the x and y coordinates of the mouse event, encoded as in X10 mode.

Wheel mice may return buttons 4 and 5. Those buttons are represented by the same event codes as buttons 1 and 2 respectively, except that 64 is added to the event code. Release events for the wheel buttons are not reported.

Mouse hilite tracking notifies a program of a button press, receives a range of lines from the program, highlights the region covered by the mouse within that range until button release, and then sends the program the release coordinates. It is enabled by specifying parameter 1001 to DECSET. Highlighting is performed only for button 1, though other button events can be received. Warning: use of this mode requires a cooperating program or it will hang xterm. On button press, the same information as for normal tracking is generated; xterm then waits for the program to send mouse tracking information. All X events are ignored until the proper escape sequence is received from the pty: CSI P s ; P s ; P s ; P s ; P s T . The parameters are func, startx, starty, firstrow, and lastrow. func is non-zero to initiate hilite tracking and zero to abort. startx and starty give the starting x and y location for the highlighted region. The ending location tracks the mouse, but will never be above row firstrow and will always be above row lastrow. (The top of the screen is row 1.) When the button is released, xterm reports the ending position one of two ways: if the start and end coordinates are valid text locations: CSI t C x C y . If either coordinate is past the end of the line: CSI T C x C y C x C y C x C y . The parameters are startx, starty, endx, endy, mousex, and mousey. startx, starty, endx, and endy give the starting and ending character positions of the region. mousex and mousey give the location of the mouse at button up, which may not be over a character.

Button-event tracking is essentially the same as normal tracking, but xterm also reports button-motion events. Motion events are reported only if the mouse pointer has moved to a different character cell. It is enabled by specifying parameter 1002 to DECSET. On button press or release, xterm sends the same codes used by normal tracking mode. On button-motion events, xterm adds 32 to the event code (the third character, C b ). The other bits of the event code specify button and modifier keys as in normal mode. For example, motion into cell x,y with button 1 down is reported as CSI M @ C x C y . ( @ = 32 + 0 (button 1) + 32 (motion indicator) ). Similarly, motion with button 3 down is reported as CSI M B C x C y . ( B = 32 + 2 (button 3) + 32 (motion indicator) ).

Any-event mode is the same as button-event mode, except that all motion events are reported, even if no mouse button is down. It is enabled by specifying 1003 to DECSET.

Tektronix 4014 Mode

Most of these sequences are standard Tektronix 4014 control sequences. Graph mode supports the 12-bit addressing of the Tektronix 4014. The major features missing are the write-through and defocused modes. This document does not describe the commands used in the various Tektronix plotting modes but does describe the commands to switch modes.

BEL

Bell (Ctrl-G)

BS

Backspace (Ctrl-H)

TAB

Horizontal Tab (Ctrl-I)

LF

Line Feed or New Line (Ctrl-J)

VT

Cursor up (Ctrl-K)

FF

Form Feed or New Page (Ctrl-L)

CR

Carriage Return (Ctrl-M)

ESC ETX

Switch to VT100 Mode (ESC Ctrl-C)

ESC ENQ

Return Terminal Status (ESC Ctrl-E)

ESC FF

PAGE (Clear Screen) (ESC Ctrl-L)

ESC SO

Begin 4015 APL mode (ignored by xterm) (ESC Ctrl-N)

ESC SI

End 4015 APL mode (ignored by xterm) (ESC Ctrl-O)

ESC ETB

COPY (Save Tektronix Codes to file COPYyyyy-mm-dd.hh:mm:ss) (ESC Ctrl-W)

ESC CAN

Bypass Condition (ESC Ctrl-X)

ESC SUB

GIN mode (ESC Ctrl-Z)

ESC FS

Special Point Plot Mode (ESC Ctrl-\)

ESC 8

Select Large Character Set

ESC 9

Select #2 Character Set

ESC :

Select #3 Character Set

ESC ;

Select Small Character Set

OSC P s ; P t BEL

Set Text Parameters of VT window P s = 0 → Change Icon Name and Window Title to P t P s = 1 → Change Icon Name to P t P s = 2 → Change Window Title to P t P s = 4 6 → Change Log File to P t (normally disabled by a compile-time option)

VT52 Mode

Parameters for cursor movement are at the end of the ESC Y escape sequence. Each ordinate is encoded in a single character as value+32. For example, ! is 1. The screen coodinate system is 0-based.

ESC A

Cursor up.

ESC B

Cursor down.

ESC C

Cursor right.

ESC D

Cursor left.

ESC F

Enter graphics mode.

ESC G

Exit graphics mode.

ESC H

Move the cursor to the home position.

ESC I

Reverse line feed.

ESC J

Erase from the cursor to the end of the screen.

ESC K

Erase from the cursor to the end of the line.

ESC Y P s P s

Move the cursor to given row and column.

ESC Z

Identify → ESC / Z (‘‘I am a VT52.’’)

ESC =

Enter alternate keypad mode.

ESC >

Exit alternate keypad mode.

ESC <

Exit VT52 mode (Enter VT100 mode).