#!/usr/bin/less

                        XTerm Control Sequences

                               Edward Moy
                   University of California, Berkeley

                               Revised by

                             Stephen Gildea
                          X Consortium (1994)

                             Thomas Dickey
                      XFree86 Project (1996-2006)
                    invisible-island.net (2006-2019)
               updated for XTerm Patch #347 (2019/05/28)

Definitions

c    The literal character c.

C    A single (required) character.

Ps   A single (usually optional) numeric parameter, composed of one or
     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.  Con-
    sequently there is no ambiguity in the way this document uses the
    term "character" to refer to bytes in a control sequence.

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 con-
    trol sequences because ECMA-48's rules are unambiguous.

    As a special case, ECMA-48 (section 9) mentions that the control
    functions 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).

    ECMA-48 describes only correct behavior, telling what types of char-
    acters are expected at each stage of the control sequences.  It says
    that the action taken in error recovery is implementation-dependent.
    XTerm decodes control sequences using a state machine.  It handles
    errors in decoding i.e., unexpected characters, by resetting to the
    initial (ground) state.  That is different from the treatment of
    unimplemented (but correctly formatted) features.

    If an application does not send the string terminator, that is also
    an error from the standpoint of a user.  To accommodate users of
    those applications, xterm has resource settings which allow work-
    arounds:

    o   The Linux console's palette sequences do not use a string termi-
        nator.  The brokenLinuxOSC resource setting tells xterm to
        ignore those particular sequences.

    o   The terminal should accept single-byte controls within the
        string.  But some applications omit a string terminator, like
        the Linux console.  The brokenStringTerm resource setting tells
        xterm to exit string mode if it decodes a common control charac-
        ter such as carriage return before the string terminator.

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:

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), VT220.
     This affects next character only.

ESC O
     Single Shift Select of G3 Character Set (SS3  is 0x8f), VT220.
     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

In this document, "VT100" refers not only to VT100/VT102, but also to
the succession of upward-compatible terminals produced by DEC (Digital
Equipment Corporation) from the mid-1970s for about twenty years.  For
brevity, the document refers to the related models:
  "VT200" as VT220/VT240,
  "VT300" as VT320/VT340,
  "VT400" as VT420, and
  "VT500" as VT510/VT520/VT525.

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 ECMA-48 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 ECMA-48, 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        Switch to Standard Character Set (Ctrl-O is Shift In or LS0).
          This invokes the G0 character set (the default) as GL.
          VT200 and up implement LS0.

SO        Switch to Alternate Character Set (Ctrl-N is Shift Out or
          LS1).  This invokes the G1 character set as GL.
          VT200 and up implement LS1.

SP        Space.

TAB       Horizontal Tab (HT) (Ctrl-I).

VT        Vertical Tab (Ctrl-K).  This is treated the same as LF.

Controls beginning with ESC

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), VT220.  This tells the terminal to
          send C1 control characters as 7-bit sequences, e.g., its
          responses to queries.  DEC VT200 and up always accept 8-bit
          control sequences except when configured for VT100 mode.

ESC SP G  8-bit controls (S8C1T), VT220.  This tells the terminal to
          send C1 control characters as 8-bit sequences, e.g., its
          responses to queries.  DEC VT200 and up always accept 8-bit
          control sequences except when configured for VT100 mode.

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), VT100.

ESC # 4   DEC double-height line, bottom half (DECDHL), VT100.

ESC # 5   DEC single-width line (DECSWL), VT100.

ESC # 6   DEC double-width line (DECDWL), VT100.

ESC # 8   DEC Screen Alignment Test (DECALN), VT100.

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, VT100, ISO 2022.
          Final character C for designating 94-character sets.  In this
          list,
          o   0 , A  and B  were introduced in the VT100,
          o   most were introduced in the VT200 series,
          o   a few were introduced in the VT300 series, and
          o   a few more were introduced in the VT500 series.
          The VT220 character sets, together with a few others (such as
          Portuguese) are activated by the National Replacement Charac-
          ter Set (NRCS) controls.  The term "replacement" says that the
          character set is formed by replacing some of the characters in
          a set (termed the Multinational Character Set) with more use-
          ful ones for a given language.  The ASCII and DEC Supplemental
          character sets make up the two halves of the Multinational
          Character set, initially mapped to GL and GR.
          The valid final characters C for this control are:
            C = A  -> United Kingdom (UK), VT100.
            C = B  -> United States (USASCII), VT100.
            C = 4  -> Dutch, VT200.
            C = C  or 5  -> Finnish, VT200.
            C = R  or f  -> French, VT200.
            C = Q  or 9  -> French Canadian, VT200.
            C = K  -> German, VT200.
            C = " >  -> Greek, VT500.
            C = % =  -> Hebrew, VT500.
            C = Y  -> Italian, VT200.
            C = ` , E  or 6  -> Norwegian/Danish, VT200.
            C = % 6  -> Portuguese, VT300.
            C = Z  -> Spanish, VT200.
            C = H  or 7  -> Swedish, VT200.
            C = =  -> Swiss, VT200.
            C = % 2  -> Turkish, VT500.
          The final character A  is a special case, since the same final
          character is used by the VT300-control for the 96-character
          British Latin-1.
          There are a few other 94-character sets:
            C = 0  -> DEC Special Character and Line Drawing Set, VT100.
            C = <  -> DEC Supplemental, VT200.
            C = >  -> DEC Technical, VT300.
          These are documented as NRCS:
            C = % 5  -> DEC Supplemental Graphics, VT300.
            C = & 4  -> DEC Cyrillic, VT500.
            C = " ?  -> DEC Greek, VT500.
            C = " 4  -> DEC Hebrew, VT500.
            C = % 0  -> DEC Turkish, VT500.
          The VT520 reference manual lists a few more, but no documenta-
          tion has been found for the mappings:
            C = & 5  -> DEC Russian, VT500.
            C = % 3  -> SCS NRCS, VT500.

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.
          These controls apply only to 96-character sets.  Unlike the
          94-character sets, these can have different values than ASCII
          space and DEL for the mapping of 0x20 and 0x7f.  The valid
          final characters C for this control are:
            C = A  -> ISO Latin-1 Supplemental (VT300).
            C = F  -> ISO Greek Supplemental (VT500).
            C = H  -> ISO Hebrew Supplemental (VT500).
            C = L  -> ISO Latin-Cyrillic (VT500).
            C = M  -> ISO Latin-5 Supplemental (VT500).

ESC . C   Designate G2 Character Set, VT300.
          The same character sets apply as for ESC - C.

ESC / C   Designate G3 Character Set, VT300.
          The same character sets apply as for ESC - C.

ESC 6     Back Index (DECBI), VT420 and up.

ESC 7     Save Cursor (DECSC), VT100.

ESC 8     Restore Cursor (DECRC), VT100.

ESC 9     Forward Index (DECFI), VT420 and up.

ESC =     Application Keypad (DECKPAM).

ESC >     Normal Keypad (DECKPNM), VT100.

ESC F     Cursor to lower left corner of screen.  This is enabled by the
          hpLowerleftBugCompat resource.

ESC c     Full Reset (RIS), VT100.

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) as GL.

ESC o     Invoke the G3 Character Set as GL (LS3) as GL.

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), VT100.

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), VT220 and up.

          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), VT420 and up.
          The string following the "q" is one of the following:
            m       -> SGR
            " p     -> DECSCL
            SP q    -> DECSCUSR
            " q     -> DECSCA
            r       -> DECSTBM
            s       -> DECSLRM
            t       -> DECSLPP
            $ |     -> DECSCPP
            * |     -> DECSNLS
          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 Ps $ t Pt ST
          Restore presentation status (DECRSPS), VT320 and up.  The con-
          trol can be converted from a response from DECCIR or DECTABSR
          by changing the first "u" to a "t"
            Ps = 1  -> DECCIR
            Ps = 2  -> DECTABSR

DCS + p Pt ST
          Set Termcap/Terminfo Data (xterm).  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 con-
          figuration's function- and special-keys, as well as by the
          Request Termcap/Terminfo String control.

DCS + q Pt ST
          Request Termcap/Terminfo String (xterm).  The string following
          the "q" is a list of names encoded in hexadecimal (2 digits
          per character) separated by ; which correspond to termcap or
          terminfo key names.
          A few special features are also recognized, which are not key
          names:
          o   Co for termcap colors (or colors for terminfo colors), and
          o   TN for termcap name (or name for terminfo name).
          o   RGB for the ncurses direct-color extension.
              Only a terminfo name is provided, since termcap applica-
              tions cannot use this information.
          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 SP @
          Shift left Ps columns(s) (default = 1) (SL), ECMA-48.

CSI Ps A  Cursor Up Ps Times (default = 1) (CUU).

CSI Ps SP A
          Shift right Ps columns(s) (default = 1) (SR), ECMA-48.

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), VT100.
            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), VT220.
            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), VT100.
            Ps = 0  -> Erase to Right (default).
            Ps = 1  -> Erase to Left.
            Ps = 2  -> Erase All.

CSI ? Ps K
          Erase in Line (DECSEL), VT220.
            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), VT420, ECMA-48.

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
              compile 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
              graphics geometry does not affect the window size.

CSI Ps T  Scroll down Ps lines (default = 1) (SD), VT420.

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 Ps ^  Scroll down Ps lines (default = 1) (SD), ECMA-48.
          This is probably an error in ECMA-48, because the standard
          writes codes as pairs of decimal values, and this is "14" ver-
          sus the VT420 "4".

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).

CSI = Ps c
          Send Device Attributes (Tertiary DA).
            Ps = 0  -> report Terminal Unit ID (default), VT400.  XTerm
          uses zeros for the site code and serial number in its DECRPTUI
          response.

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).  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).

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).
            Ps = 2 0  -> Automatic Newline (LNM).

CSI ? Pm h
          DEC Private Mode Set (DECSET).
            Ps = 1  -> Application Cursor Keys (DECCKM), VT100.
            Ps = 2  -> Designate USASCII for character sets G0-G3
          (DECANM), VT100, and set VT100 mode.
            Ps = 3  -> 132 Column Mode (DECCOLM), VT100.
            Ps = 4  -> Smooth (Slow) Scroll (DECSCLM), VT100.
            Ps = 5  -> Reverse Video (DECSCNM), VT100.
            Ps = 6  -> Origin Mode (DECOM), VT100.
            Ps = 7  -> Auto-wrap Mode (DECAWM), VT100.
            Ps = 8  -> Auto-repeat Keys (DECARM), VT100.
            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 (AT&T 610).
            Ps = 1 3  -> Start Blinking Cursor (set only via resource or
          menu).
            Ps = 1 4  -> Enable XOR of Blinking Cursor control sequence
          and menu.
            Ps = 1 8  -> Print form feed (DECPFF), VT220.
            Ps = 1 9  -> Set print extent to full screen (DECPEX),
          VT220.
            Ps = 2 5  -> Show Cursor (DECTCEM), VT220.
            Ps = 3 0  -> Show scrollbar (rxvt).
            Ps = 3 5  -> Enable font-shifting functions (rxvt).
            Ps = 3 8  -> Enter Tektronix Mode (DECTEK), VT240, xterm.
            Ps = 4 0  -> Allow 80 -> 132 Mode, xterm.
            Ps = 4 1  -> more(1) fix (see curses resource).
            Ps = 4 2  -> Enable National Replacement Character sets
          (DECNRCM), VT220.
            Ps = 4 4  -> Turn On Margin Bell, xterm.
            Ps = 4 5  -> Reverse-wraparound Mode, xterm.
            Ps = 4 6  -> Start Logging, xterm.  This is normally dis-
          abled by a compile-time option.
            Ps = 4 7  -> Use Alternate Screen Buffer, xterm.  This may
          be disabled by the titeInhibit resource.
            Ps = 6 6  -> Application keypad (DECNKM), VT320.
            Ps = 6 7  -> Backarrow key sends backspace (DECBKM), VT340,
          VT420.
            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 = 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, xterm.
            Ps = 1 0 0 2  -> Use Cell Motion Mouse Tracking, xterm.
            Ps = 1 0 0 3  -> Use All Motion Mouse Tracking, xterm.
            Ps = 1 0 0 4  -> Send FocusIn/FocusOut events, xterm.
            Ps = 1 0 0 5  -> Enable UTF-8 Mouse Mode, xterm.
            Ps = 1 0 0 6  -> Enable SGR Mouse Mode, xterm.
            Ps = 1 0 0 7  -> Enable Alternate Scroll Mode, xterm.  This
          corresponds to 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, xterm.  This sets
          eighth bit of keyboard input (and enables the eightBitInput
          resource).
            Ps = 1 0 3 5  -> Enable special modifiers for Alt and Num-
          Lock keys, xterm.  This enables the numLock resource.
            Ps = 1 0 3 6  -> Send ESC   when Meta modifies a key, xterm.
          This enables the metaSendsEscape resource.
            Ps = 1 0 3 7  -> Send DEL from the editing-keypad Delete
          key, xterm.
            Ps = 1 0 3 9  -> Send ESC  when Alt modifies a key, xterm.
          This enables the altSendsEscape resource, xterm.
            Ps = 1 0 4 0  -> Keep selection even if not highlighted,
          xterm.  This enables the keepSelection resource.
            Ps = 1 0 4 1  -> Use the CLIPBOARD selection, xterm.  This
          enables the selectToClipboard resource.
            Ps = 1 0 4 2  -> Enable Urgency window manager hint when
          Control-G is received, xterm.  This enables the bellIsUrgent
          resource.
            Ps = 1 0 4 3  -> Enable raising of the window when Control-G
          is received, xterm.  This enables the popOnBell resource.
            Ps = 1 0 4 4  -> Reuse the most recent data copied to CLIP-
          BOARD, xterm.  This enables the keepClipboard resource.
            Ps = 1 0 4 6  -> Enable switching to/from Alternate Screen
          Buffer, xterm.  This works for terminfo-based systems, updat-
          ing the titeInhibit resource.
            Ps = 1 0 4 7  -> Use Alternate Screen Buffer, xterm.  This
          may be disabled by the titeInhibit resource.
            Ps = 1 0 4 8  -> Save cursor as in DECSC, xterm.  This may
          be disabled by the titeInhibit resource.
            Ps = 1 0 4 9  -> Save cursor as in DECSC, xterm.  After sav-
          ing the cursor, switch to the Alternate Screen Buffer, clear-
          ing it first.  This may be disabled by the titeInhibit
          resource.  This control 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.
            Ps = 1 0 5 0  -> Set terminfo/termcap function-key mode,
          xterm.
            Ps = 1 0 5 1  -> Set Sun function-key mode, xterm.
            Ps = 1 0 5 2  -> Set HP function-key mode, xterm.
            Ps = 1 0 5 3  -> Set SCO function-key mode, xterm.
            Ps = 1 0 6 0  -> Set legacy keyboard emulation (i.e, X11R6),
          xterm.
            Ps = 1 0 6 1  -> Set VT220 keyboard emulation, xterm.
            Ps = 2 0 0 4  -> Set bracketed paste mode, xterm.

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, xterm.
            Ps = 1 1  -> SVG screen dump, xterm.

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).
            Ps = 2  -> Keyboard Action Mode (AM).
            Ps = 4  -> Replace Mode (IRM).
            Ps = 1 2  -> Send/receive (SRM).
            Ps = 2 0  -> Normal Linefeed (LNM).

CSI ? Pm l
          DEC Private Mode Reset (DECRST).
            Ps = 1  -> Normal Cursor Keys (DECCKM), VT100.
            Ps = 2  -> Designate VT52 mode (DECANM), VT100.
            Ps = 3  -> 80 Column Mode (DECCOLM), VT100.
            Ps = 4  -> Jump (Fast) Scroll (DECSCLM), VT100.
            Ps = 5  -> Normal Video (DECSCNM), VT100.
            Ps = 6  -> Normal Cursor Mode (DECOM), VT100.
            Ps = 7  -> No Auto-wrap Mode (DECAWM), VT100.
            Ps = 8  -> No Auto-repeat Keys (DECARM), VT100.
            Ps = 9  -> Don't send Mouse X & Y on button press, xterm.
            Ps = 1 0  -> Hide toolbar (rxvt).
            Ps = 1 2  -> Stop Blinking Cursor (AT&T 610).
            Ps = 1 3  -> Disable Blinking Cursor (reset only via
          resource or menu).
            Ps = 1 4  -> Disable XOR of Blinking Cursor control sequence
          and menu.
            Ps = 1 8  -> Don't print form feed (DECPFF).
            Ps = 1 9  -> Limit print to scrolling region (DECPEX).
            Ps = 2 5  -> Hide Cursor (DECTCEM), VT220.
            Ps = 3 0  -> Don't show scrollbar (rxvt).
            Ps = 3 5  -> Disable font-shifting functions (rxvt).
            Ps = 4 0  -> Disallow 80 -> 132 Mode, xterm.
            Ps = 4 1  -> No more(1) fix (see curses resource).
            Ps = 4 2  -> Disable National Replacement Character sets
          (DECNRCM), VT220.
            Ps = 4 4  -> Turn Off Margin Bell, xterm.
            Ps = 4 5  -> No Reverse-wraparound Mode, xterm.
            Ps = 4 6  -> Stop Logging, xterm.  This is normally disabled
          by a compile-time option.
            Ps = 4 7  -> Use Normal Screen Buffer, xterm.
            Ps = 6 6  -> Numeric keypad (DECNKM), VT320.
            Ps = 6 7  -> Backarrow key sends delete (DECBKM), VT340,
          VT420.
            Ps = 6 9  -> Disable left and right margin mode (DECLRMM),
          VT420 and up.
            Ps = 9 5  -> Clear screen when DECCOLM is set/reset (DEC-
          NCSM), VT510 and up.
            Ps = 1 0 0 0  -> Don't send Mouse X & Y on button press and
          release.  See the section Mouse Tracking.
            Ps = 1 0 0 1  -> Don't use Hilite Mouse Tracking, xterm.
            Ps = 1 0 0 2  -> Don't use Cell Motion Mouse Tracking,
          xterm.
            Ps = 1 0 0 3  -> Don't use All Motion Mouse Tracking, xterm.
            Ps = 1 0 0 4  -> Don't send FocusIn/FocusOut events, xterm.
            Ps = 1 0 0 5  -> Disable UTF-8 Mouse Mode, xterm.
            Ps = 1 0 0 6  -> Disable SGR Mouse Mode, xterm.
            Ps = 1 0 0 7  -> Disable Alternate Scroll Mode, xterm.  This
          corresponds to the alternateScroll resource.
            Ps = 1 0 1 0  -> Don't scroll to bottom on tty output
          (rxvt).
            Ps = 1 0 1 1  -> Don't scroll to bottom on key press (rxvt).
            Ps = 1 0 1 5  -> Disable urxvt Mouse Mode.
            Ps = 1 0 3 4  -> Don't interpret "meta" key, xterm.  This
          disables the eightBitInput resource.
            Ps = 1 0 3 5  -> Disable special modifiers for Alt and Num-
          Lock keys, xterm.  This disables the numLock resource.
            Ps = 1 0 3 6  -> Don't send ESC  when Meta modifies a key,
          xterm.  This disables the metaSendsEscape resource.
            Ps = 1 0 3 7  -> Send VT220 Remove from the editing-keypad
          Delete key, xterm.
            Ps = 1 0 3 9  -> Don't send ESC when Alt modifies a key,
          xterm.  This disables the altSendsEscape resource.
            Ps = 1 0 4 0  -> Do not keep selection when not highlighted,
          xterm.  This disables the keepSelection resource.
            Ps = 1 0 4 1  -> Use the PRIMARY selection, xterm.  This
          disables the selectToClipboard resource.
            Ps = 1 0 4 2  -> Disable Urgency window manager hint when
          Control-G is received, xterm.  This disables the bellIsUrgent
          resource.
            Ps = 1 0 4 3  -> Disable raising of the window when Control-
          G is received, xterm.  This disables the popOnBell resource.
            Ps = 1 0 4 6  -> Disable switching to/from Alternate Screen
          Buffer, xterm.  This works for terminfo-based systems, updat-
          ing the titeInhibit resource.  If currently using the Alter-
          nate Screen Buffer, xterm switches to the Normal Screen Buf-
          fer.
            Ps = 1 0 4 7  -> Use Normal Screen Buffer, xterm.  Clear the
          screen first if in the Alternate Screen Buffer.  This may be
          disabled by the titeInhibit resource.
            Ps = 1 0 4 8  -> Restore cursor as in DECRC, xterm.  This
          may be disabled by the titeInhibit resource.
            Ps = 1 0 4 9  -> Use Normal Screen Buffer and restore cursor
          as in DECRC, xterm.  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.
            Ps = 1 0 5 0  -> Reset terminfo/termcap function-key mode,
          xterm.
            Ps = 1 0 5 1  -> Reset Sun function-key mode, xterm.
            Ps = 1 0 5 2  -> Reset HP function-key mode, xterm.
            Ps = 1 0 5 3  -> Reset SCO function-key mode, xterm.
            Ps = 1 0 6 0  -> Reset legacy keyboard emulation (i.e,
          X11R6), xterm.
            Ps = 1 0 6 1  -> Reset keyboard emulation to Sun/PC style,
          xterm.
            Ps = 2 0 0 4  -> Reset bracketed paste mode, xterm.

CSI Pm m  Character Attributes (SGR).
            Ps = 0  -> Normal (default), VT100.
            Ps = 1  -> Bold, VT100.
            Ps = 2  -> Faint, decreased intensity, ECMA-48 2nd.
            Ps = 3  -> Italicized, ECMA-48 2nd.
            Ps = 4  -> Underlined, VT100.
            Ps = 5  -> Blink, VT100.
          This appears as Bold in X11R6 xterm.
            Ps = 7  -> Inverse, VT100.
            Ps = 8  -> Invisible, i.e., hidden, ECMA-48 2nd, VT300.
            Ps = 9  -> Crossed-out characters, ECMA-48 3rd.
            Ps = 2 1  -> Doubly-underlined, ECMA-48 3rd.
            Ps = 2 2  -> Normal (neither bold nor faint), ECMA-48 3rd.
            Ps = 2 3  -> Not italicized, ECMA-48 3rd.
            Ps = 2 4  -> Not underlined, ECMA-48 3rd.
            Ps = 2 5  -> Steady (not blinking), ECMA-48 3rd.
            Ps = 2 7  -> Positive (not inverse), ECMA-48 3rd.
            Ps = 2 8  -> Visible, i.e., not hidden, ECMA-48 3rd, VT300.
            Ps = 2 9  -> Not crossed-out, ECMA-48 3rd.
            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.
            Ps = 3 9  -> Set foreground color to default, ECMA-48 3rd.
            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, ECMA-48 3rd.

          Some of the above note the edition of ECMA-48 which first
          describes a feature.  In its successive editions from 1979 to
          1991 (2nd 1979, 3rd 1984, 4th 1986, and 5th 1991), ECMA-48
          listed codes through 6 5 (skipping several toward the end of
          the range).  Most of the ECMA-48 codes not implemented in
          xterm were never implemented in a hardware terminal.  Several
          (such as 3 9  and 4 9 ) are either noted in ECMA-48 as imple-
          mentation defined, or described in vague terms.

          The successive editions of ECMA-48 give little attention to
          changes from one edition to the next, except to comment on
          features which have become obsolete.  ECMA-48 1st (1976) is
          unavailable; there is no reliable source of information which
          states whether "ANSI" color was defined in that edition, or
          later (1979).  The VT100 (1978) implemented the most commonly
          used non-color video attributes which are given in the 2nd
          edition.

          While 8-color support is described in ECMA-48 2nd edition, the
          VT500 series (introduced in 1993) were the first DEC terminals
          implementing "ANSI" color.  The DEC terminal's use of color is
          known to differ from xterm; useful documentation on this
          series became available too late to influence xterm.

          If 16-color support is compiled, the following aixterm con-
          trols 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:

            Ps = 9 0  -> Set foreground color to Black.
            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.

          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-8613-6 has been interpreted in more than one way;
              xterm allows the semicolons separating the subparameters
              in this control to be replaced by colons (but after the
              first colon, colons must be used).

          These ISO-8613-6 controls (marked in ECMA-48 5th edition as
          "reserved for future standardization") are supported by xterm:
            Pm = 3 8 ; 2 ; Pi ; Pr ; Pg ; Pb -> Set foreground color to
          the closest match in xterm's palette for the given RGB
          Pr/Pg/Pb.  The color space identifier Pi is ignored.
            Pm = 3 8 ; 5 ; Ps -> Set foreground color to Ps.
            Pm = 4 8 ; 2 ; Pi ; Pr ; Pg ; Pb -> Set background color to
          the closest match in xterm's palette for the given RGB
          Pr/Pg/Pb.  The color space identifier Pi is ignored.
            Pm = 4 8 ; 5 ; Ps -> Set background color to Ps.

          This variation on ISO-8613-6 is supported for compatibility
          with KDE konsole:
            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 = 4 8 ; 2 ; Pr ; Pg ; Pb -> Set background color to the
          closest match in xterm's palette for the given RGB Pr/Pg/Pb.

          If xterm is compiled with direct-color support, and the
          resource directColor is true, then rather than choosing the
          closest match, xterm asks the X server to directly render a
          given color.

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 identifies 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 identifies 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 VT300 & up (keyboard ready)
          and VT400 & up (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), VT220 and up.

CSI Ps ; Ps " p
          Set conformance level (DECSCL), VT220 and up.

          The first parameter selects the conformance level.  Valid val-
          ues are:
            Ps = 6 1  -> level 1, e.g., VT100.
            Ps = 6 2  -> level 2, e.g., VT200.
            Ps = 6 3  -> level 3, e.g., VT300.
            Ps = 6 4  -> level 4, e.g., VT400.
            Ps = 6 5  -> level 5, e.g., VT500.

          The second parameter selects the C1 control transmission mode.
          This is an optional parameter, ignored in conformance level 1.
          Valid values are:
            Ps = 0  -> 8-bit controls.
            Ps = 1  -> 7-bit controls (DEC factory default).
            Ps = 2  -> 8-bit controls.

          The 7-bit and 8-bit control modes can also be set by S7C1T and
          S8C1T, but DECSCL is preferred.

CSI Ps $ p
          Request ANSI mode (DECRQM).  For VT300 and up, reply DECRPM is
            CSI Ps; Pm$ y
          where Ps is the mode number as in SM/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
          DECRPM is
            CSI ? Ps; Pm$ y
          where Ps is the mode number as in DECSET/DECSET, Pm is the
          mode value as in the ANSI DECRQM.
          Two private modes are read-only (i.e., 1 3  and 1 4 ), pro-
          vided only for reporting their values using this control
          sequence.  They correspond to the resources cursorBlink and
          cursorBlinkXOR.
CSI # p
CSI Ps ; Ps # p
          Push video attributes onto stack (XTPUSHSGR), xterm.  This is
          an alias for CSI # { , used to work around language limita-
          tions of C#.

CSI Ps q  Load LEDs (DECLL), VT100.
            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 # q   Pop video attributes from stack (XTPOPSGR), xterm.  This is an
          alias for CSI # } , used to work around language limitations
          of C#.

CSI Ps ; Ps r
          Set Scrolling Region [top;bottom] (default = full size of win-
          dow) (DECSTBM), VT100.

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, available only when DECLRMM is disabled (SCOSC,
          also ANSI.SYS).

CSI Pl ; Pr s
          Set left and right margins (DECSLRM), VT420 and up.  This is
          available only when DECLRMM is enabled.

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 by
          xterm).  These controls may be disabled using the allowWin-
          dowOps resource.

          xterm uses Extended Window Manager Hints (EWMH) to maximize
          the window.  Some window managers have incomplete support for
          EWMH.  For instance, fvwm, flwm and quartz-wm advertise sup-
          port for maximizing windows horizontally or vertically, but in
          fact equate those to the maximize operation.

          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 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.
          Note: X Toolkit positions can be negative, but the reported
          values are unsigned, in the range 0-65535.  Negative values
          correspond to 32768-65535.
          Result is CSI 3 ; x ; y t
            Ps = 1 3 ;  2  -> Report xterm text-area position.
          Result is CSI 3 ; x ; y t
            Ps = 1 4  -> Report xterm text area size in pixels.
          Result is CSI  4 ;  height ;  width t
            Ps = 1 4 ;  2  -> Report xterm window size in pixels.
          Normally xterm's window is larger than its text area, since it
          includes the frame (or decoration) applied by the window man-
          ager, as well as the area used by a scroll-bar.
          Result is CSI  4 ;  height ;  width t
            Ps = 1 5  -> Report size of the screen in pixels.
          Result is CSI  5 ;  height ;  width t
            Ps = 1 6  -> Report xterm character size in pixels.
          Result is CSI  6 ;  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), VT340 and VT420.
          xterm adapts this by resizing its window.

CSI > Ps ; Ps t
          This xterm control sets 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 (SCORC, also ANSI.SYS).

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 Ps $ w
          Request presentation state report (DECRQPSR), VT320 and up.
            Ps = 0  -> error.
            Ps = 1  -> cursor information report (DECCIR).
          Response is
            DCS 1 $ u Pt ST
          Refer to the VT420 programming manual, which requires six
          pages to document the data string Pt,
            Ps = 2  -> tab stop report (DECTABSR).
          Response is
            DCS 2 $ u Pt ST
          The data string Pt is a list of the tab-stops, separated by
          "/" characters.

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.
            Pn = 1  <- 2 8  receive 38.4k baud.
            Pn = 1  <- clock multiplier.
            Pn = 0  <- STP flags.

CSI Ps * x
          Select Attribute Change Extent (DECSACE), VT420 and up.
            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 Ps # y
          Select checksum extension (XTCHECKSUM), xterm.  The bits of Ps
          modify the calculation of the checksum returned by DECRQCRA:
            0  -> do not negate the result.
            1  -> do not report the VT100 video attributes.
            2  -> do not omit checksum for blanks.
            3  -> omit checksum for cells not explicitly initialized.
            4  -> do not mask cell value to 8 bits or ignore combining
          characters.
            5  -> do not mask cell value to 7 bits.

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 # {
CSI Ps ; Ps # {
          Push video attributes onto stack (XTPUSHSGR), xterm.  The
          optional parameters correspond to the SGR encoding for video
          attributes, except for colors (which do not have a unique SGR
          code):
            Ps = 1  -> Bold.
            Ps = 2  -> Faint.
            Ps = 3  -> Italicized.
            Ps = 4  -> Underlined.
            Ps = 5  -> Blink.
            Ps = 7  -> Inverse.
            Ps = 8  -> Invisible.
            Ps = 9  -> Crossed-out characters.
            Ps = 1 0  -> Foreground color.
            Ps = 1 1  -> Background color.
            Ps = 2 1  -> Doubly-underlined.

          If no parameters are given, all of the video attributes are
          saved.  The stack is limited to 10 levels.

CSI Pt ; Pl ; Pb ; Pr $ {
          Selective Erase Rectangular Area (DECSERA), VT400 and up.
            Pt ; Pl ; Pb ; Pr denotes the rectangle.

CSI Pt ; Pl ; Pb ; Pr # |
          Report selected graphic rendition (XTREPORTSGR), xterm.  The
          response is an SGR sequence which contains the attributes
          which are common to all cells in a rectangle.
            Pt ; Pl ; Pb ; Pr denotes the rectangle.

CSI Ps $ |
          Select columns per page (DECSCPP), VT340.
            Ps = 0  -> 80 columns, default if Ps omitted.
            Ps = 8 0  -> 80 columns.
            Ps = 1 3 2  -> 132 columns.

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 Ps * |
          Select number of lines per screen (DECSNLS), VT420 and up.

CSI # }   Pop video attributes from stack (XTPOPSGR), xterm.  Popping
          restores the video-attributes which were saved using XTPUSHSGR
          to their previous state.

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.
            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 = 4 ; c ; spec -> Change Color Number c to the color
          specified 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 (however, the dynamic text fore-
          ground and background colors are used when ANSI colors are
          reset using SGR 3 9  and 4 9 , respectively).  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 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.

            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 , q , s , 0 , 1 , 2 , 3 , 4 , 5 , 6 , and 7 .  It is
          used to construct a list of selection parameters for clip-
          board, primary, secondary, 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 (RFC-4648).  The data
          becomes the new selection, which is then available for pasting
          by other applications.

          If the second parameter is a ? , xterm replies to the host
          with the selection data encoded using the same protocol.  It
          uses the first selection found by asking successively for each
          item from the list of selection parameters.

          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.

            Ps = I  ; c -> Set icon to file.  Sun shelltool, CDE dtterm.
          The file is expected to be XPM format, and uses the same
          search logic as the iconHint resource.

            Ps = l  ; c -> Set window title.  Sun shelltool, CDE dtterm.

            Ps = L  ; c -> Set icon label.  Sun shelltool, CDE dtterm.

Privacy Message

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

Alt and Meta Keys

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:

o   prefix a key with the ESC  character.

o   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

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.

                    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.

The codes used for the PC-style function keys were inspired by a feature
of the VT510, referred to in its reference manual as DECFNK.  In the
DECFNK scheme, codes 2-8 identify modifiers for function-keys and cur-
sor-, editing-keypad keys.  Unlike xterm, the VT510 limits the modifiers
which can be used with cursor- and editing-keypad keys.  Although the
name "DECFNK" implies that it is a mode, the VT510 manual mentions it
only as a feature, which (like xterm) interacts with the DECUDK feature.
Unlike xterm, VT510/VT520 provide an extension to DECUDK (DECPFK and
DECPAK) which apparently was the reason for the feature in those termi-
nals, i.e., for identifying a programmable key rather than making it
simple for applications to obtain modifier information.  It is not
described in the related VT520 manual.  Neither manual was readily
available at the time the feature was added to xterm.

On the other hand, the VT510 and VT520 reference manuals do document a
related feature.  That is its emulation of the SCO console, which is
similar to the "xterm-sco" terminal description.  The SCO console func-
tion-keys are less useful to applications developers than the approach
used by xterm because

o   the relationship between modifiers and the characters sent by func-
    tion-keys is not readily apparent, and

o   the scheme is not extensible, i.e., it is an ad hoc asssignment lim-
    ited to two modifiers (shift and control).

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 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

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

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 compatibility 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, where button is 1, 2 or 3.

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
    button was pressed and are added together:  4=Shift, 8=Meta, 16=Con-
    trol.  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 transla-
    tions for button events.  The Meta modifier recognized by xterm is
    the mod1 mask, and is not necessarily the "Meta" key (see
    xmodmap(1)).

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 Buffer.  The initial state of Alternate
Scroll mode is set using the alternateScroll resource.

Other buttons

Additional buttons are encoded like the wheel mice,

o   by adding 64 (for buttons 6 and 7), or

o   by adding 128 (for buttons 8 through 11).

Past button 11, the encoding is ambiguous because the same code may cor-
respond to different button/modifier combinations.  It is not possible
to use these buttons (6-11) in xterm's translation resource because
their names are not in the X Toolkit's symbol table.

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.

o   func is non-zero to initiate highlight tracking and zero to abort.

o   startx and starty give the starting x and y location for the high-
    lighted region.

o   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.

    o   startx, starty, endx, and endy give the starting and ending
        character positions of the region.

    o   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

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.

Some of the sequences are specific to xterm.  The Tektronix emulation
was added in X10R4 (1986).  The VT240, introduced two years earlier,
also supported Tektronix 4010/4014.  Unlike xterm, the VT240 documenta-
tion implies (there is an obvious error in section 6.9 "Entering and
Exiting 4010/4014 Mode") that exiting back to ANSI mode is done by
resetting private mode 3 8  (DECTEK) rather than ESC ETX .  A real Tek-
tronix 4014 would not respond to either.

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.").

Further reading
Technical manuals

Manuals for hardware terminals are more readily available than simi-
larly-detailed documentation for terminal emulators such as aixterm,
shelltool, dtterm.

However long, the technical manuals have problems:

o   DEC's manuals did not provide a comprehensive comparison of the fea-
    tures in different model.

    Peter Sichel's Host Interface Functions Checklist spreadsheet is
    useful for noting which model introduced a given feature (although
    there are a few apparent errors such as the DECRQSS feature cited
    for VT320 whereas the technical manual omits it).

o   Sometimes the manuals disagree.  For example, DEC's standard docu-
    ment (DEC STD 070) for terminals says that DECSCL performs a soft
    reset (DECSTR), while the VT420 manual says it does a hard reset
    (RIS).

o   Sometimes the manuals are simply incorrect.  For example, testing a
    DEC VT420 in 1996 showed that the documented code for a valid or
    invalid response to DECRQSS was reversed.

    The VT420 test results were incorporated into vttest program.  At
    the time, DEC STD 070 was not available, but it also agrees with
    vttest.  Later, documentation for the DEC VT525 was shown to have
    the same flaw.

o   Not all details are clear even in DEC STD 070 (which is more than
    twice the length of the VT520 programmer's reference manual, and
    almost three times longer than the VT420 reference manual).  How-
    ever, as an internal standards document, DEC STD 070 is more likely
    to describe the actual behavior of DEC's terminals than the more
    polished user's guides.

That said, here are technical manuals which have been used in developing
xterm.  Not all were available initially.  In August 1996 for instance,
the technical references were limited to EK-VT220-HR-002 and EK-
VT420-UG.002.  Shortly after, Richard Shuford sent a copy of EK-VT3XX-
TP-001.  Still later (beginning in 2003), Paul Williams' vt100.net site
provided EK-VT102-UG-003, EK-VT220-RM-002, EK-VT420-RM-002, EK-VT520-RM
A01, EK-VT100-TM-003, and EK-VT102-UG-003.  The remaining documents were
found on the bitsavers site.

o   DECscope User's Manual.
    Digital Equipment Corporation (EK-VT5X-OP-001 1975).

o   VT100 Series Video Terminal Technical Manual.
    Digital Equipment Corporation (EK-VT100-TM-003, July 1982).

o   VT100 User Guide.
    Digital Equipment Corporation (EK-VT100-UG-003, June 1981).

o   VT102 User Guide.
    Digital Equipment Corporation (EK-VT102-UG-003, February 1982).

o   VT220 Programmer Pocket Guide.
    Digital Equipment Corporation (EK-VT220-HR-002, July 1984).

o   VT220 Programmer Reference Manual.
    Digital Equipment Corporation (EK-VT220-RM-002, August 1984).

o   VT240 Programmer Reference Manual.
    Digital Equipment Corporation (EK-VT240-RM-002, October 1984).

o   VT330/VT340 Programmer Reference Manual
    Volume 1: Text Programming.
    Digital Equipment Corporation (EK-VT3XX-TP-001, March 1987).

o   VT330/VT340 Programmer Reference Manual
    Volume 2: Graphics Programming.
    Digital Equipment Corporation (EK-VT3XX-GP-001, March 1987).

o   Installing and Using
    The VT420 Video Terminal
    (North American Model).
    Digital Equipment Corporation (EK-VT420-UG.002, February 1990).

o   VT420 Programmer Reference Manual.
    Digital Equipment Corporation (EK-VT420-RM-002, February 1992).

o   VT510 Video Terminal
    Programmer Information.
    Digital Equipment Corporation (EK-VT510-RM B01, November 1993).

o   VT520/VT525 Video Terminal
    Programmer Information.
    Digital Equipment Corporation (EK-VT520-RM A01, July 1994).

o   Digital ANSI-Compliant Printing Protocol
    Level 2 Programming Reference Manual
    Digital Equipment Corporation (EK-PPLV2-PM B01, August 1994).

o   4014 and 4014-1 Computer Display Terminal
    User's Manual.
    Tektronix, Inc.  (070-1647-00, November 1979).

Standards

The DEC terminal family (VT100 through VT525) is upward-compatible,
using standards plus extensions, e.g., "private modes".  Not all com-
monly-used features are standard.  For example, scrolling regions are
not found in ECMA-48.

o   ECMA-35: Character Code Structure and Extension Techniques
    (6th Edition, December 1994).

o   ECMA-48: Control Functions for Coded Character Sets
    (5th Edition, June 1991).

o   DEC STD 070 Video Systems Reference Manual.
    Digital Equipment Corporation (A-MN-ELSM070-00-0000 Rev H, December
    3, 1991).

Miscellaneous

A few hardware terminals survived into the 1990s only as terminal emula-
tors.  Documentation for these and other terminal emulators which have
influenced xterm are generally available only in less-accessible and
less-detailed manual pages.

o   XTerm supports control sequences for manipulating its window which
    were implemented by Sun's shelltool program.  This was part of Sun-
    View (SunOS 3.0, 1986).  The change-notes for xterm's resize program
    in X10.4 (1986) mention its use of these "Sun tty emulation escape
    sequences" for resizing the window.  The X10.4 xterm program recog-
    nized these sequences for resizing the terminal, except for the
    iconfig/deiconfy pair.  SunView also introduced the SIGWINCH signal,
    used by the X10.4 xterm and mentioned in its CHANGES file:

        The window size is passed to the operating system via TIOCSWINSZ
        (4.3) or TIOCSSIZE (sun).  A SIGWINCH signal is sent if the
        vtXXX window is resized.

    While support for the Sun control-sequences remained in resize, the
    next release of xterm (X11R1 in 1987) omitted the code for inter-
    preting them.

    Later, the SunView program was adapted for the OPEN LOOK environment
    introduced 1988-1990.

    Still later, in 1995, OPEN LOOK was abandoned in favor of CDE.  The
    CDE terminal emulator dtterm implemented those controls, with a cou-
    ple of additions.

    Starting in July 1996, xterm re-implemented those control sequences
    (based on the dtterm manual pages) and further extended the group of
    window controls.

    There were two sets of controls (CSI Ps[ ; Pm ; Pm]t , and OSC
    PstextST ) implemented by shelltool, documented in appendix E of
    both PHIGS Programming Manual (1992), and the unpublished X Window
    System User's Guide (OPEN LOOK Edition) (1995).  The CDE program
    kept those, and added a few new ones.

    Code         Sun   CDE   xterm   Description
    -----------------------------------------------------------------
    CSI 1 t      yes   yes    yes    de-iconify
    CSI 2 t      yes   yes    yes    iconify
    CSI 3 t      yes   yes    yes    move window to pixel-position
    CSI 4 t      yes   yes    yes    resize window in pixels
    CSI 5 t      yes   yes    yes    raise window to front of stack
    CSI 6 t      yes   yes    yes    raise window to back of stack
    CSI 7 t      yes   yes    yes    refresh window
    CSI 8 t      yes   yes    yes    resize window in chars
    CSI 9 t       -     -     yes    maximize/unmaximize window
    CSI 1 0 t     -     -     yes    to/from full-screen
    CSI 1 1 t    yes   yes    yes    report if window is iconified
    CSI 1 2 t     -     -      -     -
    CSI 1 3 t    yes   yes    yes    report window position
    CSI 1 4 t    yes   yes    yes    report window size in pixels
    CSI 1 5 t     -     -     yes    report screen size in pixels
    CSI 1 6 t     -     -     yes    report character cell in pixels
    CSI 1 7 t     -     -      -     -
    CSI 1 8 t    yes   yes    yes    report window size in chars
    CSI 1 9 t     -     -     yes    report screen size in chars
    CSI 2 0 t     -    yes    yes    report icon label
    CSI 2 1 t     -    yes    yes    report window title
    CSI 2 2 t     -     -     yes    save window/icon title
    CSI 2 3 t     -     -     yes    restore window/icon title
    CSI 2 4 t     -     -     yes    resize window (DECSLPP)
    OSC 0 ST      -    yes    yes    set window and icon title
    OSC 1 ST      -    yes    yes    set icon label
    OSC 2 ST      -    yes    yes    set window title
    OSC 3 ST      -    n/a    yes    set X server property
    OSC I ST     yes   yes    yes    set icon to file
    OSC l ST     yes   yes    yes    set window title
    OSC L ST     yes   yes    yes    set icon label

    Besides the Sun-derived OSC controls for setting window title and
    icon label, dtterm also supported the xterm controls for the same
    feature.

    The CDE source was unavailable for inspection until 2012, so that
    clarification of the details of the window operations relied upon
    vttest.

o   The control sequences for saving/restoring the cursor and for sav-
    ing/restoring "DEC Private Mode Values" may appear to be related
    (since the "save" controls both end with s ), but that is coinciden-
    tal.  The latter was introduced in X10.4:

        Most Dec Private mode settings can be save away internally using
        \E[?ns, where n is the same number to set or reset the Dec
        Private mode.  The mode can be restored using \E[?nr.  This can
        be used in termcap for vi, for example, to turn off saving of
        lines, but restore whatever the original state was on exit.

    while  the  SCOSC/SCORC pair was added in 1995 by XFree86 (and docu-
    mented long afterwards).

o   The aixterm manual page gives the format of the control sequence for
    foreground  and  background  colors  8-15, but does not specify what
    those colors are.  That is implied by the description's  mention  of
    HFT:

        The aixterm command provides a standard terminal type for
        programs that do not interact directly with Enhanced X-Windows.
        This command provides an emulation for a VT102 terminal or a
        high function terminal (HFT).  The VT102 mode is activated by
        the -v flag.

    Unlike xterm, there are no resource names for the 16 colors, leaving
    the reader to assume that the mapping is  hard-coded.   The  control
    sequences  for  colors 8-15 are not specified by ECMA-48, but rather
    (as done in other instances by xterm) chosen to  not  conflict  with
    current or future standards.
