This page lists all control sequences of xterm, which ESPTerm uses as a reference implementation.

Features and sequences not supported by ESPTerm are grayed out, added text is in green color or in gray boxes like this one.

This document was adapted from http://invisible-island.net/xterm/.


ctlseqs(ms)


                  XTerm and ESPTerm Control Sequences

                               Edward Moy
                   University of California, Berkeley

                               Revised by

                             Stephen Gildea
                          X Consortium (1994)

                             Thomas Dickey
                      XFree86 Project (1996-2006)
                    invisible-island.net (2006-2017)
               updated for XTerm Patch #329 (2017/06/11)

Definitions

c    The literal character c.

C    A single (required) character.

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

Pm   A multiple numeric parameter composed of any number of single
     numeric parameters, separated by ;  character(s).  Individual val-
     ues for the parameters are listed with Ps .

Pt   A text parameter composed of printable characters.

Control Bytes, Characters, and Sequences

ECMA-48 (aka "ISO 6429") documents C1 (8-bit) and C0 (7-bit) codes.
Those are respectively codes 128 to 159 and 0 to 31.  ECMA-48 avoids
referring to these codes as characters, because that term is associated
with graphic characters.  Instead, it uses "bytes" and "codes", with
occasional lapses to "characters" where the meaning cannot be mistaken.

Controls (including the escape code 27) are processed once:

o This means that a C1 control can be mistaken for badly-formed UTF-8
  when the terminal runs in UTF-8 mode because C1 controls are valid
  continuation bytes of a UTF-8 encoded (multibyte) value.

o It is not possible to use a C1 control obtained from decoding the
  UTF-8 text, because that would require reprocessing the data.  Conse-
  quently there is no ambiguity in the way this document uses the term
  "character" to refer to bytes in a control sequence.


	

ESPTerm implements 7-bit mode with full UTF-8 support enabled at all times. C1 codes thus cannot be used with the terminal.

Bytes with the highest bit set (0x80-0xFF) are interpreted as part of a UTF-8 code point and if the received multi-byte sequence is invalid, they are discarded.

The order of processing is a necessary consequence of the way ECMA-48 is designed: o Each byte sent to the terminal can be unambiguously determined to fall into one of a few categories (C0, C1 and graphic characters). o ECMA-48 is modal; once it starts processing a control sequence, the terminal continues until the sequence is complete, or some byte is found which is not allowed in the sequence. o Intermediate, parameter and final bytes may use the same codes as graphic characters, but they are processed as part of a control sequence and are not actually graphic characters. o Eight-bit controls can have intermediate, etc., bytes in the range 160 to 255. Those can be treated as their counterparts in the range 32 to 127. o Single-byte controls can be handled separately from multi-byte control sequences because ECMA-48's rules are unambiguous. As a special case, ECMA-48 (section 9) mentions that the control func- tions shift-in and shift-out are allowed to occur within a 7-bit multibyte control sequence because those cannot alter the meaning of the control sequence. o Some controls (such as OSC ) introduce a string mode, which is ended on a ST (string terminator). Again, the terminal should accept single-byte controls within the string. However, xterm has a resource setting brokenLinuxOSC to allow recovery from applications which rely upon malformed palette sequences used by the Linux console.

ESPTerm allows only graphic characters and UTF-8 in string mode commands like OSC.

Low ASCII control characters (< 32) are acted upon immediately on reception, with the exception of ST and BEL, which both terminate the string and execute the command.

CAN and SUB cause an immediate reset of the parser, discarding any command or sequence currently being processed.

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 equiva-
lent:


	

ESPTerm supports only the 7-bit versions, eg. ESC D.

Sequences not implemented are still consumed by the parser, but have no effect, with the exception of SOS, PM and APC, which start a string terminated by ST or BEL. The string is discarded upon completion.

ESC D Index (IND is 0x84). ESC E Next Line (NEL is 0x85). ESC H Tab Set (HTS is 0x88). ESC M Reverse Index (RI is 0x8d). ESC N Single Shift Select of G2 Character Set (SS2 is 0x8e). This affects next character only. ESC O Single Shift Select of G3 Character Set (SS3 is 0x8f). This affects next character only. ESC P Device Control String (DCS is 0x90). ESC V Start of Guarded Area (SPA is 0x96). ESC W End of Guarded Area (EPA is 0x97). ESC X Start of String (SOS is 0x98). ESC Z Return Terminal ID (DECID is 0x9a). Obsolete form of CSI c (DA). ESC [ Control Sequence Introducer (CSI is 0x9b). ESC \ String Terminator (ST is 0x9c). ESC ] Operating System Command (OSC is 0x9d). ESC ^ Privacy Message (PM is 0x9e). ESC _ Application Program Command (APC is 0x9f). 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, VT320,
VT420, VT510), as well as ISO 6429 and aixterm color controls.  The only
VT102 feature not supported is auto-repeat, since the only way X pro-
vides for this will affect all windows.
There are additional control sequences to provide xterm-dependent func-
tions, 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 paren-
theses.
The escape codes to designate and invoke character sets are specified by
ISO 2022 (see that document for a discussion of character sets).
Many of the features are optional; xterm can be configured and built
without support for them.

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).  (FF  is Ctrl-L).  FF  is treated
          the same as LF .
LF        Line Feed or New Line (NL).  (LF  is Ctrl-J).
SI        Shift In (Ctrl-O) -> Switch to Standard Character Set.  This
          invokes the G0 character set (the default).
SO        Shift Out (Ctrl-N) -> Switch to Alternate Character Set.  This
          invokes the G1 character set.
SP        Space.
TAB       Horizontal Tab (HT) (Ctrl-I).
VT        Vertical Tab (Ctrl-K).  This is treated the same as LF.


	

ESPTerm's answerbackString has the form SOS ESPTerm VERSION ST (SOS and ST as described in C1 (8-Bit) Control Characters).

Controls beginning with ESC

Most escape sequences that are not implemented in ESPTerm are still safely consumed and discarded by the parser.

This excludes controls 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.  That is ISO 8859-1 (ISO 2022).
ESC % G   Select UTF-8 character set (ISO 2022).
ESC ( C   Designate G0 Character Set (ISO 2022, VT100).
          Final character C for designating 94-character sets.  In this
          list, 0 , A  and B  apply to VT100 and up, the remainder to
          VT220 and up.  The VT220 character sets, together with the
          Portuguese character set are activated by the National
          Replacement Character controls.  The A  is a special case,
          since it is also activated by the VT300-control for British
          Latin-1 separately from the National Replacement Character
          controls.
            C = 0  -> DEC Special Character and Line Drawing Set.
            C = 1  -> Augmented DOS page 437
            C = <  -> DEC Supplementary (VT200).
            C = % 5  -> DEC Supplementary Graphics (VT300).
            C = >  -> DEC Technical (VT300).
            C = A  -> United Kingdom (UK).
            C = B  -> United States (USASCII). (default)
            C = 4  -> Dutch.
            C = C  or 5  -> Finnish.
            C = R  or f  -> French.
            C = Q  or 9  -> French Canadian (VT200, VT300).
            C = K  -> German.
            C = Y  -> Italian.
            C = ` , E  or 6  -> Norwegian/Danish.
            C = % 6  -> Portuguese (VT300).
            C = Z  -> Spanish.
            C = H  or 7  -> Swedish.
            C = =  -> Swiss.

ESC ) C   Designate G1 Character Set (ISO 2022, VT100).
          The same character sets apply as for ESC ( C.
ESC * C   Designate G2 Character Set (ISO 2022, VT220).
          The same character sets apply as for ESC ( C.
ESC + C   Designate G3 Character Set (ISO 2022, VT220).
          The same character sets apply as for ESC ( C.
ESC - C   Designate G1 Character Set (VT300).
          The same character sets apply as for ESC ( C.
ESC . C   Designate G2 Character Set (VT300).
          The same character sets apply as for ESC ( C.
ESC / C   Designate G3 Character Set (VT300).
          These work for 96-character sets only.
            C = A  -> ISO Latin-1 Supplemental.
ESC 6     Back Index (DECBI), VT420 and up.
ESC 7     Save Cursor (DECSC).
ESC 8     Restore Cursor (DECRC).
ESC 9     Forward Index (DECFI), VT420 and up.
ESC =     Application Keypad (DECKPAM).
ESC >     Normal Keypad (DECKPNM).
ESC F     Cursor to lower left corner of screen.  This is enabled by the
          hpLowerleftBugCompat resource. This is always enabled
ESC c     Full Reset (RIS).
ESC l     Memory Lock (per HP terminals).  Locks memory above the cur-
          sor.
ESC m     Memory Unlock (per HP terminals).
ESC n     Invoke the G2 Character Set as GL (LS2).
ESC o     Invoke the G3 Character Set as GL (LS3).
ESC |     Invoke the G3 Character Set as GR (LS3R).
ESC }     Invoke the G2 Character Set as GR (LS2R).
ESC ~     Invoke the G1 Character Set as GR (LS1R).

Application Program-Command functions

APC Pt ST None.  xterm implements no APC  functions; Pt is ignored.  Pt
          need not be printable characters.

Device-Control functions

DCS Ps; Ps| Pt ST
          User-Defined Keys (DECUDK).  The first parameter:
            Ps = 0  -> Clear all UDK definitions before starting
          (default).
            Ps = 1  -> Erase Below (default).
          The second parameter:
            Ps = 0  <- Lock the keys (default).
            Ps = 1  <- Do not lock.
          The third parameter is a ';'-separated list of strings denot-
          ing 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).
DCS $ q Pt ST
          Request Status String (DECRQSS).  The string following the "q"
          is one of the following:
            " q     -> DECSCA
            " p     -> DECSCL
            r       -> DECSTBM
            s       -> DECSLRM
            m       -> SGR
            SP q    -> DECSCUSR
          xterm responds with DCS 1 $ r Pt ST for valid requests,
          replacing the Pt with the corresponding CSI string, or DCS 0 $
          r Pt ST for invalid requests.
DCS + p Pt ST
          Set Termcap/Terminfo Data (xterm, experimental).  The string
          following the "p" is a name to use for retrieving data from
          the terminal database.  The data will be used for the "tcap"
          keyboard configuration's function- and special-keys, as well
          as by the Request Termcap/Terminfo String control.
DCS + q Pt ST
          Request Termcap/Terminfo String (xterm, experimental).  The
          string following the "q" is a list of names encoded in hexa-
          decimal (2 digits per character) separated by ; which corre-
          spond to termcap or terminfo key names.
          Two special features are also recognized, which are not key
          names: Co for termcap colors (or colors for terminfo colors),
          and TN for termcap name (or name for terminfo name).
          xterm responds with DCS 1 + r Pt ST for valid requests, adding
          to Pt an = , and the value of the corresponding string that
          xterm would send, or DCS 0 + r Pt ST for invalid requests.
          The strings are encoded in hexadecimal (2 digits per charac-
          ter).

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

CSI Ps @  Insert Ps (Blank) Character(s) (default = 1) (ICH).
CSI Ps A  Cursor Up Ps Times (default = 1) (CUU).
CSI Ps B  Cursor Down Ps Times (default = 1) (CUD).
CSI Ps C  Cursor Forward Ps Times (default = 1) (CUF).
CSI Ps D  Cursor Backward Ps Times (default = 1) (CUB).
CSI Ps E  Cursor Next Line Ps Times (default = 1) (CNL).
CSI Ps F  Cursor Preceding Line Ps Times (default = 1) (CPL).
CSI Ps G  Cursor Character Absolute  [column] (default = [row,1]) (CHA).
CSI Ps ; Ps H
          Cursor Position [row;column] (default = [1,1]) (CUP).
CSI Ps I  Cursor Forward Tabulation Ps tab stops (default = 1) (CHT).
CSI Ps J  Erase in Display (ED).
            Ps = 0  -> Erase Below (default).
            Ps = 1  -> Erase Above.
            Ps = 2  -> Erase All.
            Ps = 3  -> Erase Saved Lines (xterm).
CSI ? Ps J
          Erase in Display (DECSED).
            Ps = 0  -> Selective Erase Below (default).
            Ps = 1  -> Selective Erase Above.
            Ps = 2  -> Selective Erase All.
            Ps = 3  -> Selective Erase Saved Lines (xterm).
CSI Ps K  Erase in Line (EL).
            Ps = 0  -> Erase to Right (default).
            Ps = 1  -> Erase to Left.
            Ps = 2  -> Erase All.
CSI ? Ps K
          Erase in Line (DECSEL).
            Ps = 0  -> Selective Erase to Right (default).
            Ps = 1  -> Selective Erase to Left.
            Ps = 2  -> Selective Erase All.
CSI Ps L  Insert Ps Line(s) (default = 1) (IL).
CSI Ps M  Delete Ps Line(s) (default = 1) (DL).
CSI Ps P  Delete Ps Character(s) (default = 1) (DCH).
CSI Ps S  Scroll up Ps lines (default = 1) (SU).
CSI ? Pi; Pa; Pv S
          If configured to support either Sixel Graphics or ReGIS Graph-
          ics, xterm accepts a three-parameter control sequence, where
          Pi, Pa and Pv are the item, action and value:

            Pi = 1  -> item is number of color registers.
            Pi = 2  -> item is Sixel graphics geometry (in pixels).
            Pi = 3  -> item is ReGIS graphics geometry (in pixels).

            Pa = 1  -> read
            Pa = 2  -> reset to default
            Pa = 3  -> set to value in Pv
            Pa = 4  -> read the maximum allowed value

            Pv can be omitted except when setting (Pa == 3 ).
            Pv = n <- A single integer is used for color registers.
            Pv = width; height <- Two integers for graphics geometry.

          xterm replies with a control sequence of the same form:

               CSI ? Pi; Ps; Pv S

          where Ps is the status:
            Ps = 0  -> success.
            Ps = 1  -> error in Pi.
            Ps = 2  -> error in Pa.
            Ps = 3  -> failure.

          On success, Pv represents the value read or set.

          Notes:
          o The current implementation allows reading the graphics
            sizes, but disallows modifying those sizes because that is
            done once, using resource-values.
          o Graphics geometry is not necessarily the same as "window
            size" (see the dtterm window manipulation extensions). For
            example, xterm limits the maximum graphics geometry at com-
            pile time (1000x1000 as of version 328) although the window
            size can be larger.
          o While resizing a window will always change the current
            graphics geometry, the reverse is not true.  Setting graph-
            ics geometry does not affect the window size.
CSI Ps T  Scroll down Ps lines (default = 1) (SD).
CSI Ps ; Ps ; Ps ; Ps ; Ps T
          Initiate highlight mouse tracking.  Parameters are
          [func;startx;starty;firstrow;lastrow].  See the section Mouse
          Tracking.
CSI > Ps; Ps T
          Reset one or more features of the title modes to the default
          value.  Normally, "reset" disables the feature.  It is possi-
          ble to disable the ability to reset features by compiling a
          different default for the title modes into xterm.
            Ps = 0  -> Do not set window/icon labels using hexadecimal.
            Ps = 1  -> Do not query window/icon labels using hexadeci-
          mal.
            Ps = 2  -> Do not set window/icon labels using UTF-8.
            Ps = 3  -> Do not query window/icon labels using UTF-8.
          (See discussion of "Title Modes").
CSI Ps X  Erase Ps Character(s) (default = 1) (ECH).
CSI Ps Z  Cursor Backward Tabulation Ps tab stops (default = 1) (CBT).
CSI Pm `  Character Position Absolute  [column] (default = [row,1])
          (HPA).
CSI Pm a  Character Position Relative  [columns] (default = [row,col+1])
          (HPR).
CSI Ps b  Repeat the preceding graphic character Ps times (REP).
CSI Ps c  Send Device Attributes (Primary DA).
            Ps = 0  or omitted -> request attributes from terminal.  The
          response depends on the decTerminalID resource setting.
            -> CSI ? 1 ; 2 c  ("VT100 with Advanced Video Option")
            -> CSI ? 1 ; 0 c  ("VT101 with No Options")
            -> CSI ? 6 c  ("VT102")
            -> CSI ? 6 2 ; Psc  ("VT220")
            -> CSI ? 6 3 ; Psc  ("VT320")
            -> CSI ? 6 4 ; Psc  ("VT420")
          The VT100-style response parameters do not mean anything by
          themselves.  VT220 (and higher) parameters do, telling the
          host what features the terminal supports:
            Ps = 1  -> 132-columns.
            Ps = 2  -> Printer.
            Ps = 3  -> ReGIS graphics.
            Ps = 4  -> Sixel graphics.
            Ps = 6  -> Selective erase.
            Ps = 8  -> User-defined keys.
            Ps = 9  -> National Replacement Character sets.
            Ps = 1 5  -> Technical characters.
            Ps = 1 8  -> User windows.
            Ps = 2 1  -> Horizontal scrolling.
            Ps = 2 2  -> ANSI color, e.g., VT525.
            Ps = 2 9  -> ANSI text locator (i.e., DEC Locator mode).
ESPTerm identifies itself as a VT420 with national character sets.CSI > Ps c
          Send Device Attributes (Secondary DA).
            Ps = 0  or omitted -> request the terminal's identification
          code.  The response depends on the decTerminalID resource set-
          ting.  It should apply only to VT220 and up, but xterm extends
          this to VT100.
            -> CSI  > Pp ; Pv ; Pc c
          where Pp denotes the terminal type
            Pp = 0  -> "VT100".
            Pp = 1  -> "VT220".
            Pp = 2  -> "VT240".
            Pp = 1 8 -> "VT330".
            Pp = 1 9 -> "VT340".
            Pp = 2 4 -> "VT320".
            Pp = 4 1 -> "VT420".
            Pp = 6 1 -> "VT510".
            Pp = 6 4 -> "VT520".
            Pp = 6 5 -> "VT525".
          and Pv is the firmware version (for xterm, this was originally
          the XFree86 patch number, starting with 95). For ESPTerm, this is the
          firmware version expressed as integer. In a DEC termi-nal, Pc
          indicates the ROM cartridge registration number and is always zero.

CSI Pm d  Line Position Absolute  [row] (default = [1,column]) (VPA).
CSI Pm e  Line Position Relative  [rows] (default = [row+1,column])
          (VPR).
CSI Ps ; Ps f
          Horizontal and Vertical Position [row;column] (default =
          [1,1]) (HVP). This is functionally identical to CSI Ps ; Ps H.
CSI Ps g  Tab Clear (TBC).
            Ps = 0  -> Clear Current Column (default).
            Ps = 3  -> Clear All.
CSI Pm h  Set Mode (SM).
            Ps = 2  -> Keyboard Action Mode (AM).
            Ps = 4  -> Insert Mode (IRM).
            Ps = 1 2  -> Send/receive (SRM). This option disables Local Echo when enabled (default)
            Ps = 2 0  -> Automatic Newline (LNM).
CSI ? Pm h
          DEC Private Mode Set (DECSET).
            Ps = 1  -> Application Cursor Keys (DECCKM).
            Ps = 2  -> Designate USASCII for character sets G0-G3
          (DECANM), and set VT100 mode.
            Ps = 3  -> 132 Column Mode (DECCOLM). ESPTerm doesn't have enough RAM for 132x25,
          but it implements the side effects of clearing the screen and resetting the scolling region.
            Ps = 4  -> Smooth (Slow) Scroll (DECSCLM).
            Ps = 5  -> Reverse Video (DECSCNM).
            Ps = 6  -> Origin Mode (DECOM).
            Ps = 7  -> Wraparound Mode (DECAWM).
            Ps = 8  -> Auto-repeat Keys (DECARM).
            Ps = 9  -> Send Mouse X & Y on button press.  See the sec-
          tion Mouse Tracking.  This is the X10 xterm mouse protocol.
            Ps = 1 0  -> Show toolbar (rxvt).
            Ps = 1 2  -> Start Blinking Cursor (att610).
            Ps = 1 8  -> Print form feed (DECPFF).
            Ps = 1 9  -> Set print extent to full screen (DECPEX).
            Ps = 2 5  -> Show Cursor (DECTCEM).
            Ps = 3 0  -> Show scrollbar (rxvt).
            Ps = 3 5  -> Enable font-shifting functions (rxvt).
            Ps = 3 8  -> Enter Tektronix Mode (DECTEK).
            Ps = 4 0  -> Allow 80 -> 132 Mode.
            Ps = 4 1  -> more(1) fix (see curses resource).
            Ps = 4 2  -> Enable National Replacement Character sets
          (DECNRCM).
            Ps = 4 4  -> Turn On Margin Bell.
            Ps = 4 5  -> Reverse-wraparound Mode.
            Ps = 4 6  -> Start Logging.  This is normally disabled by a
          compile-time option.
            Ps = 4 7  -> Use Alternate Screen Buffer.  (This may be dis-
          abled by the titeInhibit resource). (See 1047 below for more info)
            Ps = 6 6  -> Application keypad (DECNKM).
            Ps = 6 7  -> Backarrow key sends backspace (DECBKM).
            Ps = 6 9  -> Enable left and right margin mode (DECLRMM),
          VT420 and up.
            Ps = 9 5  -> Do not clear screen when DECCOLM is set/reset
          (DECNCSM), VT510 and up.
            Ps = 8 0 0  -> Display the Action Buttons under the terminal screen (default)
            Ps = 8 0 1  -> Display the menu links under the terminal screen (default)
            Ps = 1 0 0 0  -> Send Mouse X & Y on button press and
          release.  See the section Mouse Tracking.  This is the X11
          xterm mouse protocol.
            Ps = 1 0 0 1  -> Use Hilite Mouse Tracking.
            Ps = 1 0 0 2  -> Use Cell Motion Mouse Tracking.
            Ps = 1 0 0 3  -> Use All Motion Mouse Tracking.
            Ps = 1 0 0 4  -> Send FocusIn/FocusOut events.
            Ps = 1 0 0 5  -> Enable UTF-8 Mouse Mode.
            Ps = 1 0 0 6  -> Enable SGR Mouse Mode.
            Ps = 1 0 0 7  -> Enable Alternate Scroll Mode, i.e., the
          alternateScroll resource.
            Ps = 1 0 1 0  -> Scroll to bottom on tty output (rxvt).
            Ps = 1 0 1 1  -> Scroll to bottom on key press (rxvt).
            Ps = 1 0 1 5  -> Enable urxvt Mouse Mode.
            Ps = 1 0 3 4  -> Interpret "meta" key, sets eighth bit.
          (enables the eightBitInput resource).
            Ps = 1 0 3 5  -> Enable special modifiers for Alt and Num-
          Lock keys.  (This enables the numLock resource).
            Ps = 1 0 3 6  -> Send ESC   when Meta modifies a key.  (This
          enables the metaSendsEscape resource).
            Ps = 1 0 3 7  -> Send DEL from the editing-keypad Delete
          key.
            Ps = 1 0 3 9  -> Send ESC  when Alt modifies a key.  (This
          enables the altSendsEscape resource).
            Ps = 1 0 4 0  -> Keep selection even if not highlighted.
          (This enables the keepSelection resource).
            Ps = 1 0 4 1  -> Use the CLIPBOARD selection.  (This enables
          the selectToClipboard resource).
            Ps = 1 0 4 2  -> Enable Urgency window manager hint when
          Control-G is received.  (This enables the bellIsUrgent
          resource).
            Ps = 1 0 4 3  -> Enable raising of the window when Control-G
          is received.  (enables the popOnBell resource).
            Ps = 1 0 4 4  -> Reuse the most recent data copied to CLIP-
          BOARD.  (This enables the keepClipboard resource).
            Ps = 1 0 4 7  -> Use Alternate Screen Buffer.  (This may be
          disabled by the titeInhibit resource).
            Ps = 1 0 4 8  -> Save cursor as in DECSC.  (This may be dis-
          abled by the titeInhibit resource).
            Ps = 1 0 4 9  -> Save cursor as in DECSC and use Alternate
          Screen Buffer, clearing it first.  (This may be disabled by
          the titeInhibit resource).  This combines the effects of the 1
          0 4 7  and 1 0 4 8  modes.  Use this with terminfo-based
          applications rather than the 4 7  mode.
ESP8266 doesn't have enough RAM to hold two screen buffers.
          Instead, we at least back up and restore the cursor, screen title, size, buttons and other
          attributes. The screen is also cleared with each buffer change.            Ps = 1 0 5 0  -> Set terminfo/termcap function-key mode.
            Ps = 1 0 5 1  -> Set Sun function-key mode.
            Ps = 1 0 5 2  -> Set HP function-key mode.
            Ps = 1 0 5 3  -> Set SCO function-key mode.
            Ps = 1 0 6 0  -> Set legacy keyboard emulation (X11R6).
            Ps = 1 0 6 1  -> Set VT220 keyboard emulation.
            Ps = 2 0 0 4  -> Set bracketed paste mode.
CSI Pm i  Media Copy (MC).
            Ps = 0  -> Print screen (default).
            Ps = 4  -> Turn off printer controller mode.
            Ps = 5  -> Turn on printer controller mode.
            Ps = 1  0  -> HTML screen dump.
            Ps = 1  1  -> SVG screen dump.
CSI ? Pm i
          Media Copy (MC, DEC-specific).
            Ps = 1  -> Print line containing cursor.
            Ps = 4  -> Turn off autoprint mode.
            Ps = 5  -> Turn on autoprint mode.
            Ps = 1  0  -> Print composed display, ignores DECPEX.
            Ps = 1  1  -> Print all pages.
CSI Pm l  Reset Mode (RM). See SM above.

CSI ? Pm l
          DEC Private Mode Reset (DECRST). See DECSET above.

CSI Pm m  Character Attributes (SGR).
            Ps = 0  -> Normal (default).
            Ps = 1  -> Bold.
            Ps = 2  -> Faint, decreased intensity (ISO 6429).
            Ps = 3  -> Italicized (ISO 6429).
            Ps = 4  -> Underlined.
            Ps = 5  -> Blink (appears as Bold).
            Ps = 7  -> Inverse.
            Ps = 8  -> Invisible, i.e., hidden (VT300).
            Ps = 9  -> Crossed-out characters (ISO 6429).
            Ps = 2 0  -> Fraktur (code from Wikipedia)
            Ps = 2 1  -> Doubly-underlined (ISO 6429).
            Ps = 2 1  -> Bold: off
            Ps = 2 2  -> Normal (neither bold nor faint).
            Ps = 2 3  -> Not italicized or Fraktur (ISO 6429).
            Ps = 2 4  -> Not underlined.
            Ps = 2 5  -> Steady (not blinking).
            Ps = 2 7  -> Positive (not inverse).
            Ps = 2 8  -> Visible, i.e., not hidden (VT300).
            Ps = 2 9  -> Not crossed-out (ISO 6429).
            Ps = 3 0  -> Set foreground color to Black.
            Ps = 3 1  -> Set foreground color to Red.
            Ps = 3 2  -> Set foreground color to Green.
            Ps = 3 3  -> Set foreground color to Yellow.
            Ps = 3 4  -> Set foreground color to Blue.
            Ps = 3 5  -> Set foreground color to Magenta.
            Ps = 3 6  -> Set foreground color to Cyan.
            Ps = 3 7  -> Set foreground color to White. = light gray
            Ps = 3 9  -> Set foreground color to default (original).
            Ps = 4 0  -> Set background color to Black.
            Ps = 4 1  -> Set background color to Red.
            Ps = 4 2  -> Set background color to Green.
            Ps = 4 3  -> Set background color to Yellow.
            Ps = 4 4  -> Set background color to Blue.
            Ps = 4 5  -> Set background color to Magenta.
            Ps = 4 6  -> Set background color to Cyan.
            Ps = 4 7  -> Set background color to White.
            Ps = 4 9  -> Set background color to default (original).

          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:
Codes 90-97 and 100-107 produce brighter versions of the base colors.            Ps = 9 0  -> Set foreground color to Black. = dark gray
            Ps = 9 1  -> Set foreground color to Red.
            Ps = 9 2  -> Set foreground color to Green.
            Ps = 9 3  -> Set foreground color to Yellow.
            Ps = 9 4  -> Set foreground color to Blue.
            Ps = 9 5  -> Set foreground color to Magenta.
            Ps = 9 6  -> Set foreground color to Cyan.
            Ps = 9 7  -> Set foreground color to White.
            Ps = 1 0 0  -> Set background color to Black.
            Ps = 1 0 1  -> Set background color to Red.
            Ps = 1 0 2  -> Set background color to Green.
            Ps = 1 0 3  -> Set background color to Yellow.
            Ps = 1 0 4  -> Set background color to Blue.
            Ps = 1 0 5  -> Set background color to Magenta.
            Ps = 1 0 6  -> Set background color to Cyan.
            Ps = 1 0 7  -> Set background color to White.

          If xterm is compiled with the 16-color support disabled, it
          supports the following, from rxvt:
            Ps = 1 0 0  -> Set foreground and background color to
          default.ESPTerm implements a standard 256-color palette which can be accessed using the following three-part SGR:          Xterm maintains a color palette whose entries are identified
          by an index beginning with zero.  If 88- or 256-color support
          is compiled, the following apply:
          o All parameters are decimal integers.
          o RGB values range from zero (0) to 255.
          o ISO-8613-3 can be interpreted in more than one way; xterm
            allows the semicolons in this control to be replaced by
            colons (but after the first colon, colons must be used).

          These ISO-8613-3 controls are supported:
            Pm = 3 8 ; 2 ; Pr; Pg; Pb -> Set foreground color to the
          closest match in xterm's palette for the given RGB Pr/Pg/Pb.
            Pm = 3 8 ; 5 ; Ps -> Set foreground color to Ps.
            Pm = 4 8 ; 2 ; Pr; Pg; Pb -> Set background color to the
          closest match in xterm's palette for the given RGB Pr/Pg/Pb.
            Pm = 4 8 ; 5 ; Ps -> Set background color to Ps.

CSI > Ps; Ps m
          Set or reset resource-values used by xterm to decide whether
          to construct escape sequences holding information about the
          modifiers pressed with a given key.  The first parameter iden-
          tifies the resource to set/reset.  The second parameter is the
          value to assign to the resource.  If the second parameter is
          omitted, the resource is reset to its initial value.
            Ps = 0  -> modifyKeyboard.
            Ps = 1  -> modifyCursorKeys.
            Ps = 2  -> modifyFunctionKeys.
            Ps = 4  -> modifyOtherKeys.
          If no parameters are given, all resources are reset to their
          initial values.
CSI Ps n  Device Status Report (DSR).
            Ps = 5  -> Status Report.
          Result ("OK") is CSI 0 n
            Ps = 6  -> Report Cursor Position (CPR) [row;column].
          Result is CSI r ; c R

          Note: it is possible for this sequence to be sent by a func-
          tion key.  For example, with the default keyboard configura-
          tion the shifted F1 key may send (with shift-, control-, alt-
          modifiers)
            CSI 1  ; 2  R , or
            CSI 1  ; 5  R , or
            CSI 1  ; 6  R , etc.
          The second parameter encodes the modifiers; values range from
          2 to 16.  See the section PC-Style Function Keys for the
          codes.  The modifyFunctionKeys and modifyKeyboard resources
          can change the form of the string sent from the modified F1
          key.

CSI > Ps n
          Disable modifiers which may be enabled via the CSI > Ps; Ps m
          sequence.  This corresponds to a resource value of "-1", which
          cannot be set with the other sequence.  The parameter identi-
          fies the resource to be disabled:
            Ps = 0  -> modifyKeyboard.
            Ps = 1  -> modifyCursorKeys.
            Ps = 2  -> modifyFunctionKeys.
            Ps = 4  -> modifyOtherKeys.
          If the parameter is omitted, modifyFunctionKeys is disabled.
          When modifyFunctionKeys is disabled, xterm uses the modifier
          keys to make an extended sequence of functions rather than
          adding a parameter to each function key to denote the modi-
          fiers.
CSI ? Ps n
          Device Status Report (DSR, DEC-specific).
            Ps = 6  -> Report Cursor Position (DECXCPR) [row;column] as
          CSI ? r ; c R (assumes the default page, i.e., "1").
            Ps = 1 5  -> Report Printer status as CSI ? 1 0 n  (ready).
          or CSI ? 1 1 n  (not ready).
            Ps = 2 5  -> Report UDK status as CSI ? 2 0 n  (unlocked) or
          CSI ? 2 1 n  (locked).
            Ps = 2 6  -> Report Keyboard status as
          CSI ? 2 7 ; 1 ; 0 ; 0 n  (North American).
          The last two parameters apply to VT400 & up, and denote key-
          board ready and LK01 respectively.
            Ps = 5 3  -> Report Locator status as CSI ? 5 3 n  Locator
          available, if compiled-in, or CSI ? 5 0 n  No Locator, if not.
            Ps = 5 5  -> Report Locator status as CSI ? 5 3 n  Locator
          available, if compiled-in, or CSI ? 5 0 n  No Locator, if not.
            Ps = 5 6  -> Report Locator type as CSI ? 5 7 ; 1 n  Mouse,
          if compiled-in, or CSI ? 5 7 ; 0 n  Cannot identify, if not.
            Ps = 6 2  -> Report macro space (DECMSR) as CSI Pn \* { .
            Ps = 6 3  -> Report memory checksum (DECCKSR) as DCS Pt ! x
          x x x ST .
              Pt is the request id (from an optional parameter to the
          request).
              The x's are hexadecimal digits 0-9 and A-F.
            Ps = 7 5  -> Report data integrity as CSI ? 7 0 n  (ready,
          no errors).
            Ps = 8 5  -> Report multi-session configuration as CSI ? 8 3
          n  (not configured for multiple-session operation).
CSI > Ps p
          Set resource value pointerMode.  This is used by xterm to
          decide whether to hide the pointer cursor as the user types.
          Valid values for the parameter:
            Ps = 0  -> never hide the pointer.
            Ps = 1  -> hide if the mouse tracking mode is not enabled.
            Ps = 2  -> always hide the pointer, except when leaving the
          window.
            Ps = 3  -> always hide the pointer, even if leaving/entering
          the window.  If no parameter is given, xterm uses the default,
          which is 1 .
CSI ! p   Soft terminal reset (DECSTR).
          This does the same as `ESC c` ("hard reset") in ESPTerm
CSI Ps ; Ps " p
          Set conformance level (DECSCL).  Valid values for the first
          parameter:
            Ps = 6 1  -> VT100.
            Ps = 6 2  -> VT200.
            Ps = 6 3  -> VT300.
          Valid values for the second parameter:
            Ps = 0  -> 8-bit controls.
            Ps = 1  -> 7-bit controls (always set for VT100).
            Ps = 2  -> 8-bit controls.
CSI Ps $ p
          Request ANSI mode (DECRQM).  For VT300 and up, reply is
            CSI Ps; Pm$ y
          where Ps is the mode number as in RM, and Pm is the mode
          value:
            0 - not recognized
            1 - set
            2 - reset
            3 - permanently set
            4 - permanently reset
CSI ? Ps$ p
          Request DEC private mode (DECRQM).  For VT300 and up, reply is
            CSI ? Ps; Pm$ y
          where Ps is the mode number as in DECSET, Pm is the mode value
          as in the ANSI DECRQM.
CSI Ps q  Load LEDs (DECLL).
            Ps = 0  -> Clear all LEDS (default).
            Ps = 1  -> Light Num Lock.
            Ps = 2  -> Light Caps Lock.
            Ps = 3  -> Light Scroll Lock.
            Ps = 2  1  -> Extinguish Num Lock.
            Ps = 2  2  -> Extinguish Caps Lock.
            Ps = 2  3  -> Extinguish Scroll Lock.
CSI Ps SP q
          Set cursor style (DECSCUSR, VT520).
            Ps = 0  -> blinking block.
            Ps = 1  -> blinking block (default).
            Ps = 2  -> steady block.
            Ps = 3  -> blinking underline.
            Ps = 4  -> steady underline.
            Ps = 5  -> blinking bar (xterm).
            Ps = 6  -> steady bar (xterm).
CSI Ps " q
          Select character protection attribute (DECSCA).  Valid values
          for the parameter:
            Ps = 0  -> DECSED and DECSEL can erase (default).
            Ps = 1  -> DECSED and DECSEL cannot erase.
            Ps = 2  -> DECSED and DECSEL can erase.
CSI Ps ; Ps r
          Set Scrolling Region [top;bottom] (default = full size of win-
          dow) (DECSTBM).
CSI ? Pm r
          Restore DEC Private Mode Values.  The value of Ps previously
          saved is restored.  Ps values are the same as for DECSET.
CSI Pt; Pl; Pb; Pr; Ps$ r
          Change Attributes in Rectangular Area (DECCARA), VT400 and up.
            Pt; Pl; Pb; Pr denotes the rectangle.
            Ps denotes the SGR attributes to change: 0, 1, 4, 5, 7.
CSI s     Save cursor (ANSI.SYS), available only when DECLRMM is dis-
          abled. This saves only the position, not attributes.
CSI Pl; Pr s
          Set left and right margins (DECSLRM), available only when
          DECLRMM is enabled (VT420 and up).
CSI ? Pm s
          Save DEC Private Mode Values.  Ps values are the same as for
          DECSET.
CSI Ps ; Ps ; Ps t
          Window manipulation (from dtterm, as well as extensions).
          These controls may be disabled using the allowWindowOps
          resource.  Valid values for the first (and any additional
          parameters) are:
            Ps = 1  -> De-iconify window.
            Ps = 2  -> Iconify window.
            Ps = 3  ;  x ;  y -> Move window to [x, y].
            Ps = 4  ;  height ;  width -> Resize the xterm window to
          given height and width in pixels.  Omitted parameters reuse
          the current height or width.  Zero parameters use the dis-
          play's height or width.
            Ps = 5  -> Raise the xterm window to the front of the stack-
          ing order.
            Ps = 6  -> Lower the xterm window to the bottom of the
          stacking order.
            Ps = 7  -> Refresh the xterm window.
            Ps = 8  ;  height ;  width -> Resize the text area to given
          height and width in characters.  Omitted parameters reuse the
          current height or width.  Zero parameters use the display's
          height or width.
            Ps = 9  ;  0  -> Restore maximized window.
            Ps = 9  ;  1  -> Maximize window (i.e., resize to screen
          size).
            Ps = 9  ;  2  -> Maximize window vertically.
            Ps = 9  ;  3  -> Maximize window horizontally.
            Ps = 1 0  ;  0  -> Undo full-screen mode.
            Ps = 1 0  ;  1  -> Change to full-screen.
            Ps = 1 0  ;  2  -> Toggle full-screen.
            Ps = 1 1  -> Report xterm window state.  If the xterm window
          is open (non-iconified), it returns CSI 1 t .  If the xterm
          window is iconified, it returns CSI 2 t .
            Ps = 1 3  -> Report xterm window position.
          Result is CSI 3 ; x ; y t
            Ps = 1 4  -> Report xterm window in pixels.
          Result is CSI  4  ;  height ;  width t
            Ps = 1 8  -> Report the size of the text area in characters.
          Result is CSI  8  ;  height ;  width t
            Ps = 1 9  -> Report the size of the screen in characters.
          Result is CSI  9  ;  height ;  width t
            Ps = 2 0  -> Report xterm window's icon label.
          Result is OSC  L  label ST
            Ps = 2 1  -> Report xterm window's title.
          Result is OSC  l  label ST
            Ps = 2 2  ;  0  -> Save xterm icon and window title on
          stack.
            Ps = 2 2  ;  1  -> Save xterm icon title on stack.
            Ps = 2 2  ;  2  -> Save xterm window title on stack.
            Ps = 2 3  ;  0  -> Restore xterm icon and window title from
          stack.
            Ps = 2 3  ;  1  -> Restore xterm icon title from stack.
            Ps = 2 3  ;  2  -> Restore xterm window title from stack.
            Ps >= 2 4  -> Resize to Ps lines (DECSLPP).
CSI > Ps; Ps t
          Set one or more features of the title modes.  Each parameter
          enables a single feature.
            Ps = 0  -> Set window/icon labels using hexadecimal.
            Ps = 1  -> Query window/icon labels using hexadecimal.
            Ps = 2  -> Set window/icon labels using UTF-8.
            Ps = 3  -> Query window/icon labels using UTF-8.  (See dis-
          cussion of "Title Modes")
CSI Ps SP t
          Set warning-bell volume (DECSWBV, VT520).
            Ps = 0  or 1  -> off.
            Ps = 2 , 3  or 4  -> low.
            Ps = 5 , 6 , 7 , or 8  -> high.
CSI Pt; Pl; Pb; Pr; Ps$ t
          Reverse Attributes in Rectangular Area (DECRARA), VT400 and
          up.
            Pt; Pl; Pb; Pr denotes the rectangle.
            Ps denotes the attributes to reverse, i.e.,  1, 4, 5, 7.
CSI u     Restore cursor (ANSI.SYS). This restores only the position.
CSI Ps SP u
          Set margin-bell volume (DECSMBV, VT520).
            Ps = 1  -> off.
            Ps = 2 , 3  or 4  -> low.
            Ps = 0 , 5 , 6 , 7 , or 8  -> high.
CSI Pt; Pl; Pb; Pr; Pp; Pt; Pl; Pp$ v
          Copy Rectangular Area (DECCRA, VT400 and up).
            Pt; Pl; Pb; Pr denotes the rectangle.
            Pp denotes the source page.
            Pt; Pl denotes the target location.
            Pp denotes the target page.
CSI Pt ; Pl ; Pb ; Pr ' w
          Enable Filter Rectangle (DECEFR), VT420 and up.
          Parameters are [top;left;bottom;right].
          Defines the coordinates of a filter rectangle and activates
          it.  Anytime the locator is detected outside of the filter
          rectangle, an outside rectangle event is generated and the
          rectangle is disabled.  Filter rectangles are always treated
          as "one-shot" events.  Any parameters that are omitted default
          to the current locator position.  If all parameters are omit-
          ted, any locator motion will be reported.  DECELR always can-
          cels any prevous rectangle definition.
CSI Ps x  Request Terminal Parameters (DECREQTPARM).
          if Ps is a "0" (default) or "1", and xterm is emulating VT100,
          the control sequence elicits a response of the same form whose
          parameters describe the terminal:
            Ps -> the given Ps incremented by 2.
            Pn = 1  <- no parity.
            Pn = 1  <- eight bits.
            Pn = 1  <- 2  8  transmit 38.4k baud. Transmit speed (baud)
            Pn = 1  <- 2  8  receive 38.4k baud. Receive speed (baud)
            Pn = 1  <- clock multiplier.
            Pn = 0  <- STP flags.The baud rate is retrieved from a lookup table based on the current ESPTerm settings.
See the source code for the full list. Examples: 120 = 38400, 144 = 115200 baud. What this function is
good for remains a mystery??CSI Ps * x
          Select Attribute Change Extent (DECSACE).
            Ps = 0  -> from start to end position, wrapped.
            Ps = 1  -> from start to end position, wrapped.
            Ps = 2  -> rectangle (exact).
CSI Pc ; Pt ; Pl ; Pb ; Pr $ x
          Fill Rectangular Area (DECFRA), VT420 and up.
            Pc is the character to use.
            Pt; Pl; Pb; Pr denotes the rectangle.
CSI Pi ; Pg ; Pt; Pl; Pb; Pr * y
          Request Checksum of Rectangular Area (DECRQCRA), VT420 and up.
          Response is
          DCS Pi ! x x x x ST
            Pi is the request id.
            Pg is the page number.
            Pt; Pl; Pb; Pr denotes the rectangle.
            The x's are hexadecimal digits 0-9 and A-F.
CSI Ps ; Pu ' z
          Enable Locator Reporting (DECELR).
          Valid values for the first parameter:
            Ps = 0  -> Locator disabled (default).
            Ps = 1  -> Locator enabled.
            Ps = 2  -> Locator enabled for one report, then disabled.
          The second parameter specifies the coordinate unit for locator
          reports.
          Valid values for the second parameter:
            Pu = 0  <- or omitted -> default to character cells.
            Pu = 1  <- device physical pixels.
            Pu = 2  <- character cells.
CSI Pt; Pl; Pb; Pr$ z
          Erase Rectangular Area (DECERA), VT400 and up.
            Pt; Pl; Pb; Pr denotes the rectangle.
CSI Pm ' {
          Select Locator Events (DECSLE).
          Valid values for the first (and any additional parameters)
          are:
            Ps = 0  -> only respond to explicit host requests (DECRQLP).
                       (This is default).  It also cancels any filter
                       rectangle.
            Ps = 1  -> report button down transitions.
            Ps = 2  -> do not report button down transitions.
            Ps = 3  -> report button up transitions.
            Ps = 4  -> do not report button up transitions.
CSI Pt; Pl; Pb; Pr $ {
          Selective Erase Rectangular Area (DECSERA), VT400 and up.
            Pt; Pl; Pb; Pr denotes the rectangle.
CSI Ps ' |
          Request Locator Position (DECRQLP).
          Valid values for the parameter are:
            Ps = 0 , 1 or omitted -> transmit a single DECLRP locator
          report.

          If Locator Reporting has been enabled by a DECELR, xterm will
          respond with a DECLRP Locator Report.  This report is also
          generated on button up and down events if they have been
          enabled with a DECSLE, or when the locator is detected outside
          of a filter rectangle, if filter rectangles have been enabled
          with a DECEFR.

            -> CSI Pe ; Pb ; Pr ; Pc ; Pp &  w

          Parameters are [event;button;row;column;page].
          Valid values for the event:
            Pe = 0  -> locator unavailable - no other parameters sent.
            Pe = 1  -> request - xterm received a DECRQLP.
            Pe = 2  -> left button down.
            Pe = 3  -> left button up.
            Pe = 4  -> middle button down.
            Pe = 5  -> middle button up.
            Pe = 6  -> right button down.
            Pe = 7  -> right button up.
            Pe = 8  -> M4 button down.
            Pe = 9  -> M4 button up.
            Pe = 1 0  -> locator outside filter rectangle.
          The "button" parameter is a bitmask indicating which buttons
          are pressed:
            Pb = 0  <- no buttons down.
            Pb & 1  <- right button down.
            Pb & 2  <- middle button down.
            Pb & 4  <- left button down.
            Pb & 8  <- M4 button down.
          The "row" and "column" parameters are the coordinates of the
          locator position in the xterm window, encoded as ASCII deci-
          mal.
          The "page" parameter is not used by xterm.
CSI Pm ' }
          Insert Ps Column(s) (default = 1) (DECIC), VT420 and up.
CSI Pm ' ~
          Delete Ps Column(s) (default = 1) (DECDC), VT420 and up.

Operating System Commands

OSC Ps ; Pt BEL
OSC Ps ; Pt ST
          Set Text Parameters.  For colors and font, if Pt is a "?", the
          control sequence elicits a response which consists of the con-
          trol sequence which would set the corresponding value.  The
          dtterm control sequences allow you to determine the icon name
          and window title.
            Ps = 0  -> Change Icon Name and Window Title to Pt.
            Ps = 1  -> Change Icon Name to Pt.
            Ps = 2  -> Change Window Title to Pt. (same as 0)
            Ps = 3  -> Set X property on top-level window.  Pt should be
          in the form "prop=value", or just "prop" to delete the prop-
          erty
            Ps = 81-85  -> Change text of a button 1 through 5. Empty string
          makes the button appear disabled (grayed out).
            Ps = 91-95  -> Change report message of a button 1 through 5 (max 10 bytes).
          Any characters except NUL, ESC, BEL, CAN and SUB are supported.
            Ps = 4 ; c; spec -> Change Color Number c to the color spec-
          ified by spec.  This can be a name or RGB specification as per
          XParseColor.  Any number of c/spec 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.

            Ps = 5 ; c; spec -> Change Special Color Number c to the
          color specified by spec.  This can be a name or RGB specifica-
          tion as per XParseColor.  Any number of c/spec pairs may be
          given.  The special colors can also be set by adding the maxi-
          mum number of colors to these codes in an OSC 4  control:

              Pc = 0  <- resource colorBD (BOLD).
              Pc = 1  <- resource colorUL (UNDERLINE).
              Pc = 2  <- resource colorBL (BLINK).
              Pc = 3  <- resource colorRV (REVERSE).
              Pc = 4  <- resource colorIT (ITALIC).

            Ps = 6 ; c; f -> Enable/disable Special Color Number c.  OSC
          6  is the same as OSC 1 0 6 .

          The 10 colors (below) which may be set or queried using 1 0
          through 1 9  are denoted dynamic colors, since the correspond-
          ing 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.  These controls may be disabled
          using the allowColorOps resource.  At least one parameter is
          expected for Pt.  Each successive parameter changes the next
          color in the list.  The value of Ps tells the starting point
          in the list.  The colors are specified by name or RGB specifi-
          cation 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.

            Ps = 1 0  -> Change VT100 text foreground color to Pt.
            Ps = 1 1  -> Change VT100 text background color to Pt.
            Ps = 1 2  -> Change text cursor color to Pt.
            Ps = 1 3  -> Change mouse foreground color to Pt.
            Ps = 1 4  -> Change mouse background color to Pt.
            Ps = 1 5  -> Change Tektronix foreground color to Pt.
            Ps = 1 6  -> Change Tektronix background color to Pt.
            Ps = 1 7  -> Change highlight background color to Pt.
            Ps = 1 8  -> Change Tektronix cursor color to Pt.
            Ps = 1 9  -> Change highlight foreground color to Pt.

            Ps = 4 6  -> Change Log File to Pt.  (This is normally dis-
          abled by a compile-time option).

            Ps = 5 0  -> Set Font to Pt.  These controls may be disabled
          using the allowFontOps resource.  If Pt 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).
          The same rule (plus or minus sign, optional number) is used
          when querying the font.  The remainder of Pt is ignored.
          A font can be specified after a "#" index expression, by
          adding a space and then the font specifier.
          If the "TrueType Fonts" menu entry is set (the renderFont
          resource), then this control sets/queries the faceName
          resource.

            Ps = 5 1  -> reserved for Emacs shell.

            Ps = 5 2  -> Manipulate Selection Data.  These controls may
          be disabled using the allowWindowOps resource.  The parameter
          Pt is parsed as
               Pc; Pd
          The first, Pc, may contain zero or more characters from the
          set c  p  s  0  1  2  3  4  5  6  7 .  It is used to construct
          a list of selection parameters for clipboard, primary, select,
          or cut buffers 0 through 7 respectively, in the order given.
          If the parameter is empty, xterm uses s 0 , to specify the
          configurable primary/clipboard selection and cut buffer 0.
          The second parameter, Pd, gives the selection data.  Normally
          this is a string encoded in base64.  The data becomes the new
          selection, which is then available for pasting by other appli-
          cations.
          If the second parameter is a ? , xterm replies to the host
          with the selection data encoded using the same protocol.
          If the second parameter is neither a base64 string nor ? ,
          then the selection is cleared.

            Ps = 1 0 4 ; c -> Reset Color Number c.  It is reset to the
          color specified by the corresponding X resource.  Any number
          of c parameters may be given.  These parameters correspond to
          the ANSI colors 0-7, their bright versions 8-15, and if sup-
          ported, the remainder of the 88-color or 256-color table.  If
          no parameters are given, the entire table will be reset.

            Ps = 1 0 5 ; c -> Reset Special Color Number c.  It is reset
          to the color specified by the corresponding X resource.  Any
          number of c parameters may be given.  These parameters corre-
          spond to the special colors which can be set using an OSC 5
          control (or by adding the maximum number of colors using an
          OSC 4  control).

            Ps = 1 0 6 ; c; f -> Enable/disable Special Color Number c.
          The second parameter tells xterm to enable the corresponding
          color mode if nonzero, disable it if zero.

              Pc = 0  <- resource colorBDMode (BOLD).
              Pc = 1  <- resource colorULMode (UNDERLINE).
              Pc = 2  <- resource colorBLMode (BLINK).
              Pc = 3  <- resource colorRVMode (REVERSE).
              Pc = 4  <- resource colorITMode (ITALIC).
              Pc = 5  <- resource colorAttrMode (Override ANSI).

          The dynamic colors can also be reset to their default
          (resource) values:
            Ps = 1 1 0  -> Reset VT100 text foreground color.
            Ps = 1 1 1  -> Reset VT100 text background color.
            Ps = 1 1 2  -> Reset text cursor color.
            Ps = 1 1 3  -> Reset mouse foreground color.
            Ps = 1 1 4  -> Reset mouse background color.
            Ps = 1 1 5  -> Reset Tektronix foreground color.
            Ps = 1 1 6  -> Reset Tektronix background color.
            Ps = 1 1 7  -> Reset highlight color.
            Ps = 1 1 8  -> Reset Tektronix cursor color.
            Ps = 1 1 9  -> Reset highlight foreground color.

Privacy Message

PM Pt ST  xterm implements no PM  functions; Pt is ignored.  Pt need not
          be printable characters.

Alt and Meta Keys

ESPTerm does not implement Alt and Meta keys, however it implements Ctrl and some Shift keys. For more info, please move on to the next section.


Many keyboards have keys labeled "Alt".  Few have keys labeled "Meta".
However, xterm's default translations use the Meta modifier.  Common
keyboard configurations assign the Meta modifier to an "Alt" key.  By
using xmodmap one may have the modifier assigned to a different key, and
have "real" alt and meta keys.  Here is an example:

     ! put meta on mod3 to distinguish it from alt
     keycode 64 = Alt_L
     clear mod1
     add mod1 = Alt_L
     keycode 115 = Meta_L
     clear mod3
     add mod3 = Meta_L

The metaSendsEscape resource (and altSendsEscape if altIsNotMeta is set)
can be used to control the way the Meta modifier applies to ordinary
keys unless the modifyOtherKeys resource is set:
          - prefix a key with the ESC  character.
          - shift the key from codes 0-127 to 128-255 by adding 128.

The table shows the result for a given character "x" with modifiers
according to the default translations with the resources set on or off.
This assumes altIsNotMeta is set:

       -----------------------------------------------------------
       key          altSendsEscape   metaSendsEscape   result
       -----------+----------------+-----------------+------------
       x          | off            | off             | x
       Meta-x     | off            | off             | shift
       Alt-x      | off            | off             | shift
       Alt+Meta-x | off            | off             | shift
       x          | ON             | off             | x
       Meta-x     | ON             | off             | shift
       Alt-x      | ON             | off             | ESC  x
       Alt+Meta-x | ON             | off             | ESC  shift
       x          | off            | ON              | x
       Meta-x     | off            | ON              | ESC  x
       Alt-x      | off            | ON              | shift
       Alt+Meta-x | off            | ON              | ESC  shift
       x          | ON             | ON              | x
       Meta-x     | ON             | ON              | ESC  x
       Alt-x      | ON             | ON              | ESC  x
       Alt+Meta-x | ON             | ON              | ESC  x
       -----------+----------------+-----------------+------------

PC-Style Function Keys

ESPTerm's implementation of key codes is mostly based on this section and on what is expected by real applications. For example, the MicroMite Basic does not support SS3 codes, so there is a toggle for those in the settings.

A quick summary of keyboard support:

In general, the best way to check what codes are sent is to look at the UART output with an application like GtkTerm or PuTTY, if they can show the codes without interpreting them. Alternatively, connect ESPTerm to a Linux machine, start agetty on the serial port, run cat in shell and press they keys you're interested in. It will first show them as plaintext, then interpret them when you press enter. Incidentally, this can also be used to test escape sequences and application support. ESPTerm is known to run eg. mc, neovim or nano without issues.

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.

                  Key            Normal     Application
                  -------------+----------+-------------
                  Cursor Up    | CSI A    | SS3 A
                  Cursor Down  | CSI B    | SS3 B
                  Cursor Right | CSI C    | SS3 C
                  Cursor Left  | CSI D    | SS3 D
                  -------------+----------+-------------

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:

                    Key        Normal     Application
                    ---------+----------+-------------
                    Home     | CSI H    | SS3 H
                    End      | CSI F    | SS3 F
                    ---------+----------+-------------

The application keypad transmits the following escape sequences depend-
ing on the mode specified via the DECKPNM and DECKPAM 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.

      Key              Numeric    Application   Terminfo   Termcap
      ---------------+----------+-------------+----------+----------
      Space          | SP       | SS3 SP      | -        | -
      Tab            | TAB      | SS3 I       | -        | -
      Enter          | CR       | SS3 M       | kent     | @8
      PF1            | SS3 P    | SS3 P       | kf1      | k1
      PF2            | SS3 Q    | SS3 Q       | kf2      | k2
      PF3            | SS3 R    | SS3 R       | kf3      | k3
      PF4            | SS3 S    | SS3 S       | kf4      | k4
      * (multiply)   | *        | SS3 j       | -        | -
      + (add)        | +        | SS3 k       | -        | -
      , (comma)      | ,        | SS3 l       | -        | -
      - (minus)      | -        | SS3 m       | -        | -
      . (Delete)     | .        | CSI 3 ~     | -        | -
      / (divide)     | /        | SS3 o       | -        | -
      0 (Insert)     | 0        | CSI 2 ~     | -        | -
      1 (End)        | 1        | SS3 F       | kc1      | K4
      2 (DownArrow)  | 2        | CSI B       | -        | -
      3 (PageDown)   | 3        | CSI 6 ~     | kc3      | K5
      4 (LeftArrow)  | 4        | CSI D       | -        | -
      5 (Begin)      | 5        | CSI E       | kb2      | K2
      6 (RightArrow) | 6        | CSI C       | -        | -
      7 (Home)       | 7        | SS3 H       | ka1      | K1
      8 (UpArrow)    | 8        | CSI A       | -        | -
      9 (PageUp)     | 9        | CSI 5 ~     | ka3      | K3
      = (equal)      | =        | SS3 X       | -        | -
      ---------------+----------+-------------+----------+----------

They also provide 12 function keys, as well as a few other special-pur-
pose keys:

                       Key        Escape Sequence
                       ---------+-----------------
                       F1       | SS3 P
                       F2       | SS3 Q
                       F3       | SS3 R
                       F4       | SS3 S
                       F5       | CSI 1 5 ~
                       F6       | CSI 1 7 ~
                       F7       | CSI 1 8 ~
                       F8       | CSI 1 9 ~
                       F9       | CSI 2 0 ~
                       F10      | CSI 2 1 ~
                       F11      | CSI 2 3 ~
                       F12      | CSI 2 4 ~
                       ---------+-----------------

Note that F1 through F4 are prefixed with SS3 , while the other keys are
prefixed with CSI .  Older versions of xterm implement different escape
sequences for F1 through F4, with a CSI  prefix.  These can be activated
by setting the oldXtermFKeys resource.  However, since they do not cor-
respond to any hardware terminal, they have been deprecated.  (The DEC
VT220 reserves F1 through F5 for local functions such as Setup).

                       Key        Escape Sequence
                       ---------+-----------------
                       F1       | CSI 1 1 ~
                       F2       | CSI 1 2 ~
                       F3       | CSI 1 3 ~
                       F4       | CSI 1 4 ~
                       ---------+-----------------

In normal mode, i.e., a Sun/PC keyboard when the sunKeyboard resource is
false (and none of the other keyboard resources such as oldXtermFKeys
resource is set), xterm encodes function key modifiers as parameters
appended before the final character of the control sequence.  As a spe-
cial case, the SS3  sent before F1 through F4 is altered to CSI  when
sending a function key modifier as a parameter.
Generally, ESPTerm supports only Shift adn Ctrl in some combinations.
                    Code     Modifiers
                  ---------+---------------------------
                     2     | Shift
                     3     | Alt
                     4     | Shift + Alt
                     5     | Control
                     6     | Shift + Control
                     7     | Alt + Control
                     8     | Shift + Alt + Control
                     9     | Meta
                     10    | Meta + Shift
                     11    | Meta + Alt
                     12    | Meta + Alt + Shift
                     13    | Meta + Ctrl
                     14    | Meta + Ctrl + Shift
                     15    | Meta + Ctrl + Alt
                     16    | Meta + Ctrl + Alt + Shift
                  ---------+---------------------------

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

If the alwaysUseMods resource is set, the Meta modifier also is recog-
nized, 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.
Some information here may be irrelevant for ESPTerm.
The VT102/VT220 application keypad transmits unique escape sequences in
application mode, which are distinct from the cursor and scrolling key-
pad:

                  Key            Numeric    Application
                  -------------+----------+-------------
                  Space        | SP       | SS3 SP
                  Tab          | TAB      | SS3 I
                  Enter        | CR       | SS3 M
                  PF1          | SS3 P    | SS3 P
                  PF2          | SS3 Q    | SS3 Q
                  PF3          | SS3 R    | SS3 R
                  PF4          | SS3 S    | SS3 S
                  * (multiply) | *        | SS3 j
                  + (add)      | +        | SS3 k
                  , (comma)    | ,        | SS3 l
                  - (minus)    | -        | SS3 m
                  . (period)   | .        | SS3 n
                  / (divide)   | /        | SS3 o
                  0            | 0        | SS3 p
                  1            | 1        | SS3 q
                  2            | 2        | SS3 r
                  3            | 3        | SS3 s
                  4            | 4        | SS3 t
                  5            | 5        | SS3 u
                  6            | 6        | SS3 v
                  7            | 7        | SS3 w
                  8            | 8        | SS3 x
                  9            | 9        | SS3 y
                  = (equal)    | =        | SS3 X
                  -------------+----------+-------------

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

                   Key        Normal     Application
                   ---------+----------+-------------
                   Insert   | CSI 2 ~  | CSI 2 ~
                   Delete   | CSI 3 ~  | CSI 3 ~
                   Home     | CSI 1 ~  | CSI 1 ~
                   End      | CSI 4 ~  | CSI 4 ~
                   PageUp   | CSI 5 ~  | CSI 5 ~
                   PageDown | CSI 6 ~  | CSI 6 ~
                   ---------+----------+-------------

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

                       Key        Escape Sequence
                       ---------+-----------------
                       F13      | CSI 2 5 ~
                       F14      | CSI 2 6 ~
                       F15      | CSI 2 8 ~
                       F16      | CSI 2 9 ~
                       F17      | CSI 3 1 ~
                       F18      | CSI 3 2 ~
                       F19      | CSI 3 3 ~
                       F20      | CSI 3 4 ~
                       ---------+-----------------

VT52-Style Function Keys

VT52 modes are summarily not implemented in ESPTerm.
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:

                   Key            Normal/Application
                   -------------+--------------------
                   Cursor Up    | ESC A
                   Cursor Down  | ESC B
                   Cursor Right | ESC C
                   Cursor Left  | ESC D
                   -------------+--------------------

The keypad is similar:

                  Key            Numeric    Application
                  -------------+----------+-------------
                  Space        | SP       | ESC ? SP
                  Tab          | TAB      | ESC ? I
                  Enter        | CR       | ESC ? M
                  PF1          | ESC P    | ESC P
                  PF2          | ESC Q    | ESC Q
                  PF3          | ESC R    | ESC R
                  PF4          | ESC S    | ESC S
                  * (multiply) | *        | ESC ? j
                  + (add)      | +        | ESC ? k
                  , (comma)    | ,        | ESC ? l
                  - (minus)    | -        | ESC ? m
                  . (period)   | .        | ESC ? n
                  / (divide)   | /        | ESC ? o
                  0            | 0        | ESC ? p
                  1            | 1        | ESC ? q
                  2            | 2        | ESC ? r
                  3            | 3        | ESC ? s
                  4            | 4        | ESC ? t
                  5            | 5        | ESC ? u
                  6            | 6        | ESC ? v
                  7            | 7        | ESC ? w
                  8            | 8        | ESC ? x
                  9            | 9        | ESC ? y
                  = (equal)    | =        | ESC ? X
                  -------------+----------+-------------

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.

The Alternate Screen Buffer

ESPTerm implements this feature only partly due to RAM constraints. See CSI ? 1 0 4 7 h (above) for more details.
Xterm maintains two screen buffers.  The normal screen buffer allows you
to scroll back to view saved lines of output up to the maximum set by
the saveLines resource.  The alternate screen buffer is exactly as large
as the display, contains no additional saved lines.  When the alternate
screen buffer is active, you cannot scroll back to view saved lines.
Xterm provides control sequences and menu entries for switching between
the two.

Most full-screen applications use terminfo or termcap to obtain strings
used to start/stop full-screen mode, i.e., smcup and rmcup for terminfo,
or the corresponding ti and te for termcap.  The titeInhibit resource
removes the ti and te strings from the TERMCAP string which is set in
the environment for some platforms.  That is not done when xterm is
built with terminfo libraries because terminfo does not provide the
whole text of the termcap data in one piece.  It would not work for ter-
minfo anyway, since terminfo data is not passed in environment vari-
ables; setting an environment variable in this manner would have no
effect on the application's ability to switch between normal and alter-
nate screen buffers.  Instead, the newer private mode controls (such as
1 0 4 9 ) for switching between normal and alternate screen buffers sim-
ply disable the switching.  They add other features such as clearing the
display for the same reason: to make the details of switching indepen-
dent of the application that requests the switch.

Bracketed Paste Mode

When bracketed paste mode is set, pasted text is bracketed with control
sequences so that the program can differentiate pasted text from typed-
in text.  When bracketed paste mode is set, the program will receive:
   ESC [ 2 0 0 ~ ,
followed by the pasted text, followed by
   ESC [ 2 0 1 ~ .

Title Modes


The window- and icon-labels can be set or queried using control
sequences.  As a VT220-emulator, xterm "should" limit the character
encoding for the corresponding strings to ISO-8859-1.  Indeed, it used
to be the case (and was documented) that window titles had to be
ISO-8859-1.  This is no longer the case.  However, there are many appli-
cations which still assume that titles are set using ISO-8859-1.  So
that is the default behavior.

If xterm is running with UTF-8 encoding, it is possible to use window-
and icon-labels encoded using UTF-8.  That is because the underlying X
libraries (and many, but not all) window managers support this feature.

The utf8Title X resource setting tells xterm to disable a reconversion
of the title string back to ISO-8859-1, allowing the title strings to be
interpreted as UTF-8.  The same feature can be enabled using the title
mode control sequence described in this summary.

Separate from the ability to set the titles, xterm provides the ability
to query the titles, returning them either in ISO-8859-1 or UTF-8.  This
choice is available only while xterm is using UTF-8 encoding.

Finally, the characters sent to, or returned by a title control are less
constrained than the rest of the control sequences.  To make them more
manageable (and constrained), for use in shell scripts, xterm has an
optional feature which decodes the string from hexadecimal (for setting
titles) or for encoding the title into hexadecimal when querying the
value.

Mouse Tracking

The VT widget can be set to send the mouse position and other informa-
tion 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 two sets of mutually exclusive modes:
o mouse protocol
o protocol encoding

The mouse protocols include DEC Locator mode, enabled by the DECELR CSI
Ps ; Ps  '  z control sequence, and is not described here (control
sequences are summarized above).  The remaining five modes of the mouse
protocols are each enabled (or disabled) by a different parameter in the
"DECSET CSI ? Pm h " or "DECRST CSI ? Pm 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

     #define SET_FOCUS_EVENT_MOUSE       1004

     #define SET_EXT_MODE_MOUSE          1005
     #define SET_SGR_EXT_MODE_MOUSE      1006
     #define SET_URXVT_EXT_MODE_MOUSE    1015

     #define SET_ALTERNATE_SCROLL        1007

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.

Normally, 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.  This scheme dates back to X10, though the normal mouse-
tracking (from X11) is more elaborate.

X10 compatbility mode

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
CbCxCy (6 characters).
o Cb is button-1.
o Cx and Cy are the x and y coordinates of the mouse when the button was
  pressed.

Normal tracking mode

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 CbCxCy.
o The low two bits of Cb encode button information: 0=MB1 pressed, 1=MB2
  pressed, 2=MB3 pressed, 3=release.
o The next three bits encode the modifiers which were down when the but-
  ton 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).
o Cx and Cy are the x and y coordinates of the mouse event, encoded as
  in X10 mode.

Wheel mice

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.  By default, the wheel mouse events are translated to scroll-
back and scroll-forw actions.  Those actions normally scroll the whole
window, as if the scrollbar was used.  However if Alternate Scroll mode
is set, then cursor up/down controls are sent when the terminal is dis-
playing the alternate screen.  The initial state of Alternate Scroll
mode is set using the alternateScroll resource.

Highlight tracking


Mouse highlight 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 but-
ton 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 gener-
ated; xterm then waits for the program to send mouse tracking informa-
tion.  All X events are ignored until the proper escape sequence is
received from the pty: CSI Ps ; Ps ; Ps ; Ps ; Ps T .  The parameters
are func, startx, starty, firstrow, and lastrow.  func is non-zero to
initiate highlight 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:
o if the start and end coordinates are the same locations:
  CSI t CxCy.
o otherwise:
  CSI T CxCyCxCyCxCy.
  The parameters are startx, starty, endx, endy, mousex, and mousey.
  - startx, starty, endx, and endy give the starting and ending charac-
    ter 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

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.
o On button-motion events, xterm adds 32 to the event code (the third
  character, Cb).
o 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 @ CxCy.  ( @  = 32 + 0 (button 1) + 32 (motion
  indicator) ).  Similarly, motion with button 3 down is reported as CSI
  M B CxCy.  ( B  = 32 + 2 (button 3) + 32 (motion indicator) ).

Any-event tracking

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.

FocusIn/FocusOut

This feature is planned for reporting when any clients are connected to the web interface

FocusIn/FocusOut can be combined with any of the mouse events since it
uses a different protocol.  When set, it causes xterm to send CSI I
when the terminal gains focus, and CSI O  when it loses focus.

Extended coordinates

The original X10 mouse protocol limits the Cx and Cy ordinates to 223
(=255 - 32).  Xterm supports more than one scheme for extending this
range, by changing the protocol encoding:
UTF-8 (1005)
          This enables UTF-8 encoding for Cx and Cy under all tracking
          modes, expanding the maximum encodable position from 223 to
          2015.  For positions less than 95, the resulting output is
          identical under both modes.  Under extended mouse mode, posi-
          tions greater than 95 generate "extra" bytes which will con-
          fuse applications which do not treat their input as a UTF-8
          stream.  Likewise, Cb will be UTF-8 encoded, to reduce confu-
          sion with wheel mouse events.
          Under normal mouse mode, positions outside (160,94) result in
          byte pairs which can be interpreted as a single UTF-8 charac-
          ter; applications which do treat their input as UTF-8 will
          almost certainly be confused unless extended mouse mode is
          active.
          This scheme has the drawback that the encoded coordinates will
          not pass through luit unchanged, e.g., for locales using non-
          UTF-8 encoding.
SGR (1006)
          The normal mouse response is altered to use CSI < followed by
          semicolon-separated encoded button value, the Cx and Cy ordi-
          nates and a final character which is M  for button press and m
          for button release.
          o The encoded button value in this case does not add 32 since
            that was useful only in the X10 scheme for ensuring that the
            byte containing the button value is a printable code.
          o The modifiers are encoded in the same way.
          o A different final character is used for button release to
            resolve the X10 ambiguity regarding which button was
            released.
          The highlight tracking responses are also modified to an SGR-
          like format, using the same SGR-style scheme and button-encod-
          ings.
URXVT (1015)
          The normal mouse response is altered to use CSI followed by
          semicolon-separated encoded button value, the Cx and Cy ordi-
          nates and final character M .
          This uses the same button encoding as X10, but printing it as
          a decimal integer rather than as a single byte.
          However, CSI M  can be mistaken for DL (delete lines), while
          the highlight tracking CSI T  can be mistaken for SD (scroll
          down), and the Window manipulation controls.  For these rea-
          sons, the 1015 control is not recommended; it is not an
          improvement over 1005.

Sixel Graphics


If xterm is configured as VT240, VT241, VT330, VT340 or VT382 using the
decTerminalID resource, it supports Sixel Graphics controls, a palleted
bitmap graphics system using sets of six vertical pixels as the basic
element.

CSI Ps c  xterm responds to Send Device Attributes (Primary DA) with
          these additional codes:
            Ps = 4  -> Sixel graphics.
CSI ? Pm h
          xterm has these additional private Set Mode values:
            Ps = 8 0  -> Sixel scrolling.
            Ps = 1 0 7 0  -> use private color registers for each
          graphic.
            Ps = 8 4 5 2  -> Sixel scrolling leaves cursor to right of
          graphic.
DCS Pa; Pb; Ph q  Ps..Ps ST
          See:

               http://vt100.net/docs/vt3xx-gp/chapter14.html

          The sixel data device control string has three positional
          parameters, following the q  with sixel data.
            Pa -> pixel aspect ratio
            Pb -> background color option
            Ph -> horizontal grid size (ignored).
            Ps -> sixel data

ReGIS Graphics


If xterm is configured as VT125, VT240, VT241, VT330 or VT340 using the
decTerminalID resource, it supports Remote Graphic Instruction Set, a
graphics description language.

CSI Ps c  xterm responds to Send Device Attributes (Primary DA) with
          these additional codes:
            Ps = 3  -> ReGIS graphics.
CSI ? Pm h
          xterm has these additional private Set Mode values:
            Ps = 1 0 7 0  -> use private color registers for each
          graphic.
DCS Pm p Pr..Pr ST
          See:

               http://vt100.net/docs/vt3xx-gp/chapter1.html

          The ReGIS data device control string has one positional param-
          eter with four possible values:
            Pm = 0 -> resume command, use fullscreen mode.
            Pm = 1 -> start new command, use fullscreen mode.
            Pm = 2 -> resume command, use command display mode.
            Pm = 3 -> start new command, use command display mode.

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 (ESC  Ctrl-N).  (This is ignored by
          xterm).
ESC SI    End 4015 APL mode (ESC  Ctrl-O).  (This is ignored by xterm).
ESC ETB   COPY (Save Tektronix Codes to file COPYyyyy-mm-dd.hh:mm:ss).
            ETB  (end transmission block) is the same as 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 Ps ; Pt BEL
          Set Text Parameters of VT window.
            Ps = 0  -> Change Icon Name and Window Title to Pt.
            Ps = 1  -> Change Icon Name to Pt.
            Ps = 2  -> Change Window Title to Pt.
            Ps = 4 6  -> Change Log File to Pt.  (This is normally dis-
          abled by a compile-time option).
ESC `     Normal Z Axis and Normal (solid) Vectors.
ESC a     Normal Z Axis and Dotted Line Vectors.
ESC b     Normal Z Axis and Dot-Dashed Vectors.
ESC c     Normal Z Axis and Short-Dashed Vectors.
ESC d     Normal Z Axis and Long-Dashed Vectors.
ESC h     Defocused Z Axis and Normal (solid) Vectors.
ESC i     Defocused Z Axis and Dotted Line Vectors.
ESC j     Defocused Z Axis and Dot-Dashed Vectors.
ESC k     Defocused Z Axis and Short-Dashed Vectors.
ESC l     Defocused Z Axis and Long-Dashed Vectors.
ESC p     Write-Thru Mode and Normal (solid) Vectors.
ESC q     Write-Thru Mode and Dotted Line Vectors.
ESC r     Write-Thru Mode and Dot-Dashed Vectors.
ESC s     Write-Thru Mode and Short-Dashed Vectors.
ESC t     Write-Thru Mode and Long-Dashed Vectors.
FS        Point Plot Mode (Ctrl-\).
GS        Graph Mode (Ctrl-]).
RS        Incremental Plot Mode (Ctrl-^).
US        Alpha Mode (Ctrl-_).

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 coordinate system is 0-based.

ESC <     Exit VT52 mode (Enter VT100 mode).
ESC =     Enter alternate keypad mode.
ESC >     Exit alternate keypad mode.
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 Ps Ps
          Move the cursor to given row and column.
ESC Z     Identify.
            -> ESC  /  Z  ("I am a VT52.").