Page 1068
LINUX CONSOLE CONTROLS
This section describes all the control characters and escape sequences that invoke special functions (that is, 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 you have a control character, it is acted upon immediately and then discarded (even in the middle of an escape sequence) and the escape sequence 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 line).
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.
CR (0x0D, ^M) gives a carriage return.
SO (0x0E, ^N) activates the G1 character set, and if
LF/NL (new line mode) is set, also a carriage return.
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 SEQUENCES, 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, attributes, character sets). |
| ESC 8 | DECRC | Restore most recently saved state. |
| 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 Es. |
| ESC ( | Start sequence defining G0 character set. | |
| ESC ( B | Select default (ISO 8859-1 mapping). | |
| ESC ( 0 | Select vt100 graphics mapping. |
Page 1069
| 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 nrrggbb: set palette, with parameter given in 7 hexadecimal digits after the final P :-(. Here n is the color (0_16), and rrggbb indicates the red/green/blue values (0_255). ESC ] R: reset palette. |
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 key.)
The action of a CSI sequence is determined by its final character.
| Character | Function | Description |
| @ | 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. |
| 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 the current line. |
| X | ECH | Erase the indicated # of characters on the 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. |
continues