CONSOLE_CODES(4)           Linux Programmer's Manual          CONSOLE_CODES(4)

       console_codes - Linux console escape and control sequences

       The   Linux  console  implements  a  large  subset  of  the  VT102  and
       ECMA-48/ISO 6429/ANSI X3.64 terminal controls,  plus  certain  private-
       mode  sequences  for changing the color palette, character-set mapping,
       and so on.  In the tabular descriptions below, the second column  gives
       ECMA-48  or  DEC  mnemonics  (the  latter if prefixed with DEC) for the
       given function.  Sequences without a mnemonic are neither  ECMA-48  nor

       After  all  the normal output processing has been done, and a stream of
       characters arrives at the console driver for actual printing, the first
       thing  that  happens is a translation from the code used for processing
       to the code used for printing.

       If the console is in UTF-8 mode, then the incoming bytes are first  as-
       sembled into 16-bit Unicode codes.  Otherwise, each byte is transformed
       according to the current mapping table (which translates it to  a  Uni-
       code value).  See the Character Sets section below for discussion.

       In the normal case, the Unicode value is converted to a font index, and
       this is stored in video memory, so that  the  corresponding  glyph  (as
       found  in  video ROM) appears on the screen.  Note that the use of Uni-
       code (and the design of the PC hardware) allows us to use 512 different
       glyphs simultaneously.

       If  the  current  Unicode  value is a control character, or we are cur-
       rently processing an escape sequence, the value will treated specially.
       Instead  of  being turned into a font index and rendered as a glyph, it
       may trigger cursor movement or other control functions.  See the  Linux
       Console Controls section below for discussion.

       It  is  generally not good practice to hard-wire terminal controls into
       programs.  Linux supports a terminfo(5) database of terminal  capabili-
       ties.   Rather than emitting console escape sequences by hand, you will
       almost always want to use a terminfo-aware screen  library  or  utility
       such as ncurses(3), tput(1), or reset(1).

   Linux console controls
       This  section describes all the control characters and escape sequences
       that invoke special functions (i.e.,  anything  other  than  writing  a
       glyph at the current cursor location) on the Linux console.

       Control characters

       A  character is a control character if (before transformation according
       to the mapping table) it has one of the 14 codes 00 (NUL), 07 (BEL), 08
       (BS), 09 (HT), 0a (LF), 0b (VT), 0c (FF), 0d (CR), 0e (SO), 0f (SI), 18
       (CAN), 1a (SUB), 1b (ESC), 7f (DEL).  One can set  a  "display  control
       characters"  mode  (see  below), and allow 07, 09, 0b, 18, 1a, 7f to be
       displayed as glyphs.  On the other hand, in UTF-8 mode all codes  00-1f
       are  regarded as control characters, regardless of any "display control
       characters" mode.

       If we have a control character, it is acted upon immediately  and  then
       discarded (even in the middle of an escape sequence) and the escape se-
       quence continues with the next character.  (However, ESC starts  a  new
       escape  sequence,  possibly aborting a previous unfinished one, and CAN
       and SUB abort any escape sequence.)  The recognized control  characters
       are BEL, BS, HT, LF, VT, FF, CR, SO, SI, CAN, SUB, ESC, DEL, CSI.  They
       do what one would expect:

       BEL (0x07, ^G) beeps;

       BS (0x08, ^H) backspaces one column (but not past the beginning of  the

       HT  (0x09,  ^I)  goes to the next tab stop or to the end of the line if
              there is no earlier tab stop;

       LF (0x0A, ^J), VT (0x0B, ^K) and FF (0x0C, ^L) all give a linefeed, and
              if LF/NL (new-line mode) is set also a carriage return;

       CR (0x0D, ^M) gives a carriage return;

       SO (0x0E, ^N) activates the G1 character set;

       SI (0x0F, ^O) activates the G0 character set;

       CAN (0x18, ^X) and SUB (0x1A, ^Z) interrupt escape sequences;

       ESC (0x1B, ^[) starts an escape sequence;

       DEL (0x7F) is ignored;

       CSI (0x9B) is equivalent to ESC [.

       ESC- but not CSI-sequences

       ESC c     RIS      Reset.
       ESC D     IND      Linefeed.
       ESC E     NEL      Newline.
       ESC H     HTS      Set tab stop at current column.
       ESC M     RI       Reverse linefeed.
       ESC Z     DECID    DEC private identification. The kernel returns the
                          string  ESC [ ? 6 c, claiming that it is a VT102.
       ESC 7     DECSC    Save  current  state  (cursor   coordinates,   at-
                          tributes, character sets pointed at by G0, G1).
       ESC 8     DECRC    Restore state most recently saved by ESC 7.
       ESC [     CSI      Control sequence introducer
       ESC %              Start sequence selecting character set
       ESC % @               Select default (ISO 646 / ISO 8859-1)
       ESC % G               Select UTF-8
       ESC % 8               Select UTF-8 (obsolete)
       ESC # 8   DECALN   DEC screen alignment test - fill screen with E's.
       ESC (              Start sequence defining G0 character set
       ESC ( B               Select default (ISO 8859-1 mapping)
       ESC ( 0               Select VT100 graphics mapping
       ESC ( U               Select null mapping - straight to character ROM
       ESC ( K               Select user mapping - the map that is loaded by
                             the utility mapscrn(8).
       ESC )              Start sequence defining G1
                          (followed by one of B, 0, U, K, as above).
       ESC >     DECPNM   Set numeric keypad mode
       ESC =     DECPAM   Set application keypad mode
       ESC ]     OSC      (Should  be: Operating system command) ESC ] P nr-
                          rggbb: set palette,  with  parameter  given  in  7
                          hexadecimal  digits after the final P :-(.  Here n
                          is the color  (0-15),  and  rrggbb  indicates  the
                          red/green/blue  values  (0-255).   ESC  ] R: reset

       ECMA-48 CSI sequences

       CSI (or ESC [) is followed by a sequence of parameters,  at  most  NPAR
       (16),  that  are  decimal numbers separated by semicolons.  An empty or
       absent parameter is taken to be 0.  The sequence of parameters  may  be
       preceded by a single question mark.

       However,  after  CSI [ (or ESC [ [) a single character is read and this
       entire sequence is ignored.  (The idea is to ignore an echoed  function

       The action of a CSI sequence is determined by its final character.

       @   ICH       Insert the indicated # of blank characters.
       A   CUU       Move cursor up the indicated # of rows.
       B   CUD       Move cursor down the indicated # of rows.
       C   CUF       Move cursor right the indicated # of columns.
       D   CUB       Move cursor left the indicated # of columns.
       E   CNL       Move cursor down the indicated # of rows, to column 1.
       F   CPL       Move cursor up the indicated # of rows, to column 1.
       G   CHA       Move cursor to indicated column in current row.
       H   CUP       Move cursor to the indicated row, column (origin at 1,1).
       J   ED        Erase display (default: from cursor to end of display).
                     ESC [ 1 J: erase from start to cursor.
                     ESC [ 2 J: erase whole display.
                     ESC [ 3 J: erase whole display including scroll-back
                                buffer (since Linux 3.0).
       K   EL        Erase line (default: from cursor to end of line).
                     ESC [ 1 K: erase from start of line to cursor.
                     ESC [ 2 K: erase whole line.
       L   IL        Insert the indicated # of blank lines.
       M   DL        Delete the indicated # of lines.
       P   DCH       Delete the indicated # of characters on current line.
       X   ECH       Erase the indicated # of characters on current line.
       a   HPR       Move cursor right the indicated # of columns.
       c   DA        Answer ESC [ ? 6 c: "I am a VT102".
       d   VPA       Move cursor to the indicated row, current column.
       e   VPR       Move cursor down the indicated # of rows.
       f   HVP       Move cursor to the indicated row, column.
       g   TBC       Without parameter: clear tab stop at current position.
                     ESC [ 3 g: delete all tab stops.
       h   SM        Set Mode (see below).
       l   RM        Reset Mode (see below).
       m   SGR       Set attributes (see below).
       n   DSR       Status report (see below).
       q   DECLL     Set keyboard LEDs.
                     ESC [ 0 q: clear all LEDs
                     ESC [ 1 q: set Scroll Lock LED
                     ESC [ 2 q: set Num Lock LED
                     ESC [ 3 q: set Caps Lock LED
       r   DECSTBM   Set scrolling region; parameters are top and bottom row.
       s   ?         Save cursor location.
       u   ?         Restore cursor location.
       `   HPA       Move cursor to indicated column in current row.

       ECMA-48 Set Graphics Rendition

       The  ECMA-48  SGR  sequence ESC [ parameters m sets display attributes.
       Several attributes can be set in the same sequence, separated by  semi-
       colons.   An empty parameter (between semicolons or string initiator or
       terminator) is interpreted as a zero.

       param     result
       0         reset all attributes to their defaults
       1         set bold
       2         set half-bright (simulated with color on a color display)
       4         set underscore (simulated with color on a color  display)
                 (the colors used to simulate dim or underline are set us-
                 ing ESC ] ...)

       5         set blink
       7         set reverse video
       10        reset selected mapping, display control flag, and  toggle
                 meta flag (ECMA-48 says "primary font").
       11        select null mapping, set display control flag, reset tog-
                 gle meta flag (ECMA-48 says "first alternate font").
       12        select null mapping, set display control flag, set toggle
                 meta  flag  (ECMA-48  says "second alternate font").  The
                 toggle meta flag causes the high bit of a byte to be tog-
                 gled before the mapping table translation is done.
       21        set  underline;  before Linux 4.17, this value set normal
                 intensity (as is done in many other terminals)
       22        set normal intensity
       24        underline off
       25        blink off
       27        reverse video off
       30        set black foreground
       31        set red foreground
       32        set green foreground
       33        set brown foreground
       34        set blue foreground
       35        set magenta foreground
       36        set cyan foreground
       37        set white foreground
       38        256/24-bit foreground color follows, shoehorned  into  16
                 basic  colors  (before Linux 3.16: set underscore on, set
                 default foreground color)
       39        set default foreground color (before Linux 3.16: set  un-
                 derscore off, set default foreground color)
       40        set black background
       41        set red background
       42        set green background
       43        set brown background
       44        set blue background
       45        set magenta background
       46        set cyan background
       47        set white background
       48        256/24-bit  background  color  follows, shoehorned into 8
                 basic colors
       49        set default background color
       90..97    set foreground to bright versions of 30..37
       100.107   set background, same as 40..47 (bright not supported)

       Commands 38 and 48 require further arguments:

       ;5;x       256 color: values 0..15 are IBGR (black,  red,  green,
                  ...  white),  16..231  a  6x6x6 color cube, 232..255 a
                  grayscale ramp
       ;2;r;g;b   24-bit color, r/g/b components are in the range 0..255

       ECMA-48 Mode Switches

       ESC [ 3 h
              DECCRM (default off): Display control chars.

       ESC [ 4 h
              DECIM (default off): Set insert mode.

       ESC [ 20 h
              LF/NL (default off): Automatically follow echo of LF, VT  or  FF
              with CR.

       ECMA-48 Status Report Commands

       ESC [ 5 n
              Device status report (DSR): Answer is ESC [ 0 n (Terminal OK).

       ESC [ 6 n
              Cursor position report (CPR): Answer is ESC [ y ; x R, where x,y
              is the cursor location.

       DEC Private Mode (DECSET/DECRST) sequences

       These are not described in ECMA-48.  We list the  Set  Mode  sequences;
       the  Reset  Mode  sequences  are obtained by replacing the final 'h' by

       ESC [ ? 1 h
              DECCKM (default off): When set, the cursor keys send  an  ESC  O
              prefix, rather than ESC [.

       ESC [ ? 3 h
              DECCOLM (default off = 80 columns): 80/132 col mode switch.  The
              driver sources note that this alone does not suffice; some user-
              mode  utility  such  as resizecons(8) has to change the hardware
              registers on the console video card.

       ESC [ ? 5 h
              DECSCNM (default off): Set reverse-video mode.

       ESC [ ? 6 h
              DECOM (default off): When set, cursor addressing is relative  to
              the upper left corner of the scrolling region.

       ESC [ ? 7 h
              DECAWM  (default  on): Set autowrap on.  In this mode, a graphic
              character emitted after column 80 (or column 132 of  DECCOLM  is
              on) forces a wrap to the beginning of the following line first.

       ESC [ ? 8 h
              DECARM (default on): Set keyboard autorepeat on.

       ESC [ ? 9 h
              X10  Mouse  Reporting (default off): Set reporting mode to 1 (or
              reset to 0)--see below.

       ESC [ ? 25 h
              DECTECM (default on): Make cursor visible.

       ESC [ ? 1000 h
              X11 Mouse Reporting (default off): Set reporting mode to  2  (or
              reset to 0)--see below.

       Linux Console Private CSI Sequences

       The following sequences are neither ECMA-48 nor native VT102.  They are
       native to the Linux console driver.  Colors are in SGR parameters: 0  =
       black,  1 = red, 2 = green, 3 = brown, 4 = blue, 5 = magenta, 6 = cyan,
       7 = white; 8-15 = bright versions of 0-7.

       ESC [ 1 ; n ]       Set color n as the underline color.
       ESC [ 2 ; n ]       Set color n as the dim color.
       ESC [ 8 ]           Make the current color pair the default attributes.
       ESC [ 9 ; n ]       Set screen blank timeout to n minutes.
       ESC [ 10 ; n ]      Set bell frequency in Hz.
       ESC [ 11 ; n ]      Set bell duration in msec.
       ESC [ 12 ; n ]      Bring specified console to the front.
       ESC [ 13 ]          Unblank the screen.
       ESC [ 14 ; n ]      Set the VESA powerdown interval in minutes.
       ESC [ 15 ]          Bring the previous  console  to  the  front  (since
                           Linux 2.6.0).
       ESC [ 16 ; n ]      Set  the  cursor  blink  interval  in  milliseconds
                           (since Linux 4.2).

   Character sets
       The kernel knows about 4 translations of bytes into console-screen sym-
       bols.   The  four tables are: a) Latin1 -> PC, b) VT100 graphics -> PC,
       c) PC -> PC, d) user-defined.

       There are two character sets, called G0 and G1, and one of them is  the
       current  character set.  (Initially G0.)  Typing ^N causes G1 to become
       current, ^O causes G0 to become current.

       These variables G0 and G1 point at a  translation  table,  and  can  be
       changed by the user.  Initially they point at tables a) and b), respec-
       tively.  The sequences ESC ( B and ESC ( 0 and ESC (  U  and  ESC  (  K
       cause G0 to point at translation table a), b), c) and d), respectively.
       The sequences ESC ) B and ESC ) 0 and ESC ) U and ESC ) K cause  G1  to
       point at translation table a), b), c) and d), respectively.

       The  sequence  ESC c causes a terminal reset, which is what you want if
       the screen is all garbled.  The oft-advised "echo ^V^O" will make  only
       G0  current,  but there is no guarantee that G0 points at table a).  In
       some distributions there is a program reset(1)  that  just  does  "echo
       ^[c".   If  your  terminfo entry for the console is correct (and has an
       entry rs1=\Ec), then "tput reset" will also work.

       The user-defined mapping table can be set using mapscrn(8).  The result
       of  the mapping is that if a symbol c is printed, the symbol s = map[c]
       is sent to the video memory.  The bitmap that corresponds to s is found
       in the character ROM, and can be changed using setfont(8).

   Mouse tracking
       The  mouse  tracking facility is intended to return xterm(1)-compatible
       mouse status reports.  Because the console driver has no  way  to  know
       the device or type of the mouse, these reports are returned in the con-
       sole input stream only when the  virtual  terminal  driver  receives  a
       mouse  update  ioctl.   These ioctls must be generated by a mouse-aware
       user-mode application such as the gpm(8) daemon.

       The mouse tracking escape sequences generated by  xterm(1)  encode  nu-
       meric  parameters in a single character as value+040.  For example, '!'
       is 1.  The screen coordinate system is 1-based.

       The X10 compatibility mode sends an escape sequence on button press en-
       coding  the  location  and  the mouse button pressed.  It is enabled by
       sending ESC [ ? 9 h and disabled with ESC [ ? 9 l.   On  button  press,
       xterm(1)  sends  ESC [ M bxy (6 characters).  Here b is button-1, and x
       and y are the x and y coordinates of the  mouse  when  the  button  was
       pressed.  This is the same code the kernel also produces.

       Normal  tracking mode (not implemented in Linux 2.0.24) sends an escape
       sequence on both button press and  release.   Modifier  information  is
       also  sent.   It is enabled by sending ESC [ ? 1000 h and disabled with
       ESC [ ? 1000 l.  On button press or release, xterm(1)  sends  ESC  [  M
       bxy.   The  low two bits of b encode button information: 0=MB1 pressed,
       1=MB2 pressed, 2=MB3 pressed, 3=release.  The upper  bits  encode  what
       modifiers were down when the button was pressed and are added together:
       4=Shift, 8=Meta, 16=Control.  Again x and y are the x and y coordinates
       of the mouse event.  The upper left corner is (1,1).

   Comparisons with other terminals
       Many different terminal types are described, like the Linux console, as
       being "VT100-compatible".  Here  we  discuss  differences  between  the
       Linux  console  and  the  two  most important others, the DEC VT102 and

       Control-character handling

       The VT102 also recognized the following control characters:

       NUL (0x00) was ignored;

       ENQ (0x05) triggered an answerback message;

       DC1 (0x11, ^Q, XON) resumed transmission;

       DC3 (0x13, ^S, XOFF) caused VT100 to ignore (and stop transmitting) all
              codes except XOFF and XON.

       VT100-like DC1/DC3 processing may be enabled by the terminal driver.

       The  xterm(1) program (in VT100 mode) recognizes the control characters
       BEL, BS, HT, LF, VT, FF, CR, SO, SI, ESC.

       Escape sequences

       VT100 console sequences not implemented on the Linux console:

       ESC N       SS2   Single shift 2. (Select G2 character set for the next
                         character only.)
       ESC O       SS3   Single shift 3. (Select G3 character set for the next
                         character only.)
       ESC P       DCS   Device control string (ended by ESC \)
       ESC X       SOS   Start of string.
       ESC ^       PM    Privacy message (ended by ESC \)
       ESC \       ST    String terminator
       ESC * ...         Designate G2 character set
       ESC + ...         Designate G3 character set

       The program xterm(1) (in VT100 mode) recognizes ESC c, ESC # 8, ESC  >,
       ESC =, ESC D, ESC E, ESC H, ESC M, ESC N, ESC O, ESC P ... ESC \, ESC Z
       (it answers ESC [ ? 1 ; 2 c, "I am a VT100 with advanced video option")
       and  ESC ^ ... ESC \ with the same meanings as indicated above.  It ac-
       cepts ESC (, ESC ), ESC *,  ESC + followed by 0, A, B for the DEC  spe-
       cial character and line drawing set, UK, and US-ASCII, respectively.

       The  user  can  configure xterm(1) to respond to VT220-specific control
       sequences, and it will identify itself as a VT52, VT100, and up depend-
       ing on the way it is configured and initialized.

       It  accepts ESC ] (OSC) for the setting of certain resources.  In addi-
       tion to the ECMA-48 string terminator (ST), xterm(1) accepts a  BEL  to
       terminate  an OSC string.  These are a few of the OSC control sequences
       recognized by xterm(1):

       ESC ] 0 ; txt ST        Set icon name and window title to txt.
       ESC ] 1 ; txt ST        Set icon name to txt.
       ESC ] 2 ; txt ST        Set window title to txt.
       ESC ] 4 ; num; txt ST   Set ANSI color num to txt.
       ESC ] 10 ; txt ST       Set dynamic text color to txt.
       ESC ] 4 6 ; name ST     Change log file to name (normally disabled
                               by a compile-time option)
       ESC ] 5 0 ; fn ST       Set font to fn.

       It recognizes the following with slightly modified meaning (saving more
       state, behaving closer to VT100/VT220):

       ESC 7  DECSC   Save cursor
       ESC 8  DECRC   Restore cursor

       It also recognizes

       ESC F          Cursor to lower left corner of screen (if enabled by
                      xterm(1)'s hpLowerleftBugCompat resource)
       ESC l          Memory lock (per HP terminals).
                      Locks memory above the cursor.

       ESC m          Memory unlock (per HP terminals).
       ESC n   LS2    Invoke the G2 character set.
       ESC o   LS3    Invoke the G3 character set.
       ESC |   LS3R   Invoke the G3 character set as GR.
                      Has no visible effect in xterm.
       ESC }   LS2R   Invoke the G2 character set as GR.
                      Has no visible effect in xterm.
       ESC ~   LS1R   Invoke the G1 character set as GR.
                      Has no visible effect in xterm.

       It also recognizes ESC % and provides a more complete UTF-8 implementa-
       tion than Linux console.

       CSI Sequences

       Old versions of xterm(1), for example, from X11R5, interpret the  blink
       SGR  as  a bold SGR.  Later versions which implemented ANSI colors, for
       example, XFree86 3.1.2A in 1995, improved this by  allowing  the  blink
       attribute  to be displayed as a color.  Modern versions of xterm imple-
       ment blink SGR as blinking text and still allow colored text as an  al-
       ternate  rendering of SGRs.  Stock X11R6 versions did not recognize the
       color-setting  SGRs  until  the  X11R6.8  release,  which  incorporated
       XFree86  xterm.  All ECMA-48 CSI sequences recognized by Linux are also
       recognized by xterm, however xterm(1) implements  several  ECMA-48  and
       DEC control sequences not recognized by Linux.

       The  xterm(1)  program recognizes all of the DEC Private Mode sequences
       listed above, but none of the Linux private-mode sequences.   For  dis-
       cussion  of  xterm(1)'s  own private-mode sequences, refer to the Xterm
       Control Sequences document by Edward Moy, Stephen Gildea, and Thomas E.
       Dickey available with the X distribution.  That document, though terse,
       is much longer than this manual page.  For a chronological overview,


       details changes to xterm.

       The vttest program


       demonstrates many of these control sequences.  The xterm(1) source dis-
       tribution also contains sample scripts which exercise other features.

       ESC 8 (DECRC) is not able to restore the character set changed with ESC

       In 2.0.23, CSI is broken, and NUL is  not  ignored  inside  escape  se-

       Some  older  kernel  versions  (after  2.0) interpret 8-bit control se-
       quences.  These "C1 controls" use codes between 128 and 159 to  replace
       ESC  [,  ESC ] and similar two-byte control sequence initiators.  There
       are fragments of that in modern kernels (either overlooked or broken by
       changes  to  support  UTF-8),  but the implementation is incomplete and
       should be regarded as unreliable.

       Linux "private mode" sequences do not follow the rules in  ECMA-48  for
       private  mode control sequences.  In particular, those ending with ] do
       not use a standard terminating character.  The OSC  (set  palette)  se-
       quence  is  a  greater  problem, since xterm(1) may interpret this as a
       control sequence which requires a string terminator (ST).   Unlike  the
       setterm(1) sequences which will be ignored (since they are invalid con-
       trol sequences), the palette sequence will make xterm(1) appear to hang
       (though  pressing the return-key will fix that).  To accommodate appli-
       cations which have been hardcoded to use Linux control  sequences,  set
       the xterm(1) resource brokenLinuxOSC to true.

       An  older  version  of  this document implied that Linux recognizes the
       ECMA-48 control sequence for invisible text.  It is ignored.

       ioctl_console(2), charsets(7)

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       description  of  the project, information about reporting bugs, and the
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