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ansi-escape-sequences.rst

ANSI Escape Sequences

Standard escape codes are prefixed with Escape:

  • Ctrl-Key: ^[
  • Octal: \033
  • Unicode: \u001b
  • Hexadecimal: \x1B
  • Decimal: 27

Followed by the command, somtimes delimited by opening square bracket ([), known as a Control Sequence Introducer (CSI), optionally followed by arguments and the command itself.

Arguments are delimeted by semicolon (;).

For example:

\x1b[1;31m  # Set style to bold, red foreground.

Sequences

  • ESC - sequence starting with ESC (\x1b)
  • CSI - Control Sequence Introducer: sequence starting with ESC [ or CSI (\x9b)
  • DCS - Device Control String: sequence starting with ESC P or DCS (\x90)
  • OSC - Operating System Command: sequence starting with ESC ] or OSC (\x9d)

Any whitespaces between sequences and arguments should be ignored. They are present for improved readability.

General ASCII Codes

Name decimal octal hex C-escape Ctrl-Key Description
BEL 7 007 0x07 \a ^G [1] Terminal bell
BS 8 010 0x08 \b ^H Backspace
HT 9 011 0x09 \t ^I Horizontal tab
LF 10 012 0x0A \n ^J Linefeed (also newline)
VT 11 013 0x0B \v ^K Vertical tab
FF 12 014 0x0C \f ^L Formfeed (also NP new page)
CR 13 015 0x0D \r ^M Carriage return
ESC 27 033 0x1B \e [2] ^[ Escape character
DEL 127 177 0x7F <none> <none> Delete character
[1]The Ctrl-Key representation is simply associating the non-printable characters from ASCII code 1 with the printable (letter) characters from ASCII code 65 ("A"). ASCII code 1 would be ^A (Ctrl-A), while ASCII code 7 (BEL) would be ^G (Ctrl-G). This is a common representation (and input method) and historically comes from one of the VT series of terminals.
[2]Some control escape sequences, like e for ESC, are not guaranteed to work in all languages and compilers. It is recommended to use the decimal, octal or hex representation as escape code.

Cursor Controls

ESC Code Sequence Description
ESC[H moves cursor to home position (0, 0)

ESC[{line};{column}H

ESC[{line};{column}f

 moves cursor to line #, column #
ESC[#A moves cursor up # lines
ESC[#B moves cursor down # lines
ESC[#C moves cursor right # columns
ESC[#D moves cursor left # columns
ESC[#E moves cursor to beginning of next line, # lines down
ESC[#F moves cursor to beginning of previous line, # lines up
ESC[#G moves cursor to column #
ESC[6n request cursor position (reports as ESC[#;#R)
ESC M moves cursor one line up, scrolling if needed
ESC 7 save cursor position [3] (DEC)
ESC 8 restores the cursor to the last saved position (DEC)
ESC[s save cursor position (SCO)
ESC[u restores the cursor to the last saved position (SCO)
[3]Some sequences, like saving and restoring cursors, are private sequences and are not standardized. While some terminal emulators (i.e. xterm and derived) support both SCO and DEC sequences, they are likely to have different functionality. It is therefore recommended to use DEC sequences.

Erase Functions

ESC Code Sequence Description
ESC[J erase in display (same as ESC[0J)
ESC[0J erase from cursor until end of screen
ESC[1J erase from cursor to beginning of screen
ESC[2J erase entire screen
ESC[3J erase saved lines
ESC[K erase in line [4] (same as ESC[0K)
ESC[0K erase from cursor to end of line
ESC[1K erase start of line to the cursor
ESC[2K erase the entire line
[4]Erasing the line won't move the cursor, meaning that the cursor will stay at the last position it was at before the line was erased. You can use \r after erasing the line, to return the cursor to the start of the current line.

Colors / Graphics Mode

ESC Code Sequence [5] Reset Sequence Description
ESC[1;34;{...}m   set graphics modes for cell, separated by semicolon (;)
ESC[0m   reset all modes (styles and colors)
ESC[1m ESC[22m [6] set bold mode
ESC[2m ESC[22m set dim/faint mode
ESC[3m ESC[23m set italic mode
ESC[4m ESC[24m set underline mode
ESC[5m ESC[25m set blinking mode
ESC[7m ESC[27m set inverse/reverse mode
ESC[8m ESC[28m set hidden/invisible mode
ESC[9m ESC[29m set strikethrough mode
[5]Some terminals may not support some of the graphic mode sequences listed above.
[6]Both dim and bold modes are reset with the ESC[22m sequence. The ESC[21m sequence is a non-specified sequence for double underline mode and only work in some terminals and is reset with ESC[24m.

Color codes

Most terminals support 8 and 16 colors, as well as 256 (8-bit) colors. These colors are set by the user, but have commonly defined meanings.

8-16 Colors

Color Name Foreground Color Code Background Color Code
Black 30 40
Red 31 41
Green 32 42
Yellow 33 43
Blue 34 44
Magenta 35 45
Cyan 36 46
White 37 47
Default 39 49
Reset [7] 0 0
[7]the Reset color is the reset code that resets all colors and text effects, Use Default color to reset colors only.

Most terminals, apart from the basic set of 8 colors, also support the "bright" or "bold" colors. These have their own set of codes, mirroring the normal colors, but with an additional ;1 in their codes:

# Set style to bold, red foreground.
\x1b[1;31mHello

# Set style to dimmed white foreground with red background.
\x1b[2;37;41mWorld

Terminals that support the aixterm specification provides bright versions of the ISO colors, without the need to use the bold modifier:

Color Name Foreground Color Code Background Color Code
Bright Black 90 100
Bright Red 91 101
Bright Green 92 102
Bright Yellow 93 103
Bright Blue 94 104
Bright Magenta 95 105
Bright Cyan 96 106
Bright White 97 107

256 Colors

The following escape codes tells the terminal to use the given color ID:

ESC Code Sequence Description
ESC[38;5;{ID}m set foreground color
ESC[48;5;{ID}m set background color

Where {ID} should be replaced with the color index from 0 to 255 of the following color table:

https://user-images.githubusercontent.com/50381946/234837504-82985b24-9e86-4492-97d6-2d8b1ee7578e.png

The table starts with the original 16 colors (0-15).

The proceeding 216 colors (16-231) or formed by a 3bpc RGB value offset by 16, packed into a single value.

The final 24 colors (232-255) are grayscale starting from a shade slighly lighter than black, ranging up to shade slightly darker than white.

Some emulators interpret these steps as linear increments (256 / 24) on all three channels, although some emulators may explicitly define these values.

RGB Colors

More modern terminals supports Truecolor (24-bit RGB), which allows you to set foreground and background colors using RGB.

These escape sequences are usually not well documented.

ESC Code Sequence Description
ESC[38;2;{r};{g};{b}m set foreground color as RGB
ESC[48;2;{r};{g};{b}m set background color as RGB
Note:
;38 and ;48 corresponds to the 16 color sequence and is interpreted by the terminal to set the foreground and background color respectively. Where as ;2 and ;5 sets the color format.

Common Private Modes

These are some examples of private modes, which are not defined by the specification, but are implemented in most terminals.

ESC Code Sequence Description
ESC[?25l make cursor invisible
ESC[?25h make cursor visible
ESC[?47l restore screen
ESC[?47h save screen
ESC[?1049h enables the alternative buffer
ESC[?1049l disables the alternative buffer

Refer to the XTerm Control Sequences for a more in-depth list of private modes defined by XTerm.

Note:
While these modes may be supported by the most terminals, some may not work in multiplexers like tmux.
ReST layout:Alexandr Shavykin
Contact:[email protected]
Date:25-May-25 18:53:53 PDT
Origin:https://gist.github.com/fnky/458719343aabd01cfb17a3a4f7296797
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