DECARM — Auto-repeat keys mode (CSI ? 8 h / l)

Byte forms

Every common string-literal form so you can paste-and-search either direction.

Description

Auto-Repeat Mode. When set (`\x1b[?8h`, the default in nearly every terminal), holding down a key after the OS-defined repeat delay (typically 250 ms) causes the terminal to inject repeated key bytes at the OS-defined repeat rate (typically 30/sec) — the standard typewriter-style behaviour. When reset (`\x1b[?8l`), the terminal sends exactly one byte per physical keypress regardless of how long the key is held — so a roguelike that interprets `j` as 'move down once' won't see the player skipping across the map when they hold the key. The OS-defined delay/rate isn't tunable via DECARM (use `xset r rate` on X11, `defaults write -g KeyRepeat` on macOS, accessibility panel on Windows); DECARM only flips on/off. Critical for TUI games (curses-based roguelikes like nethack, brogue), action editors that interpret modal-style single-keystroke commands, and applications that want every keystroke debounced into a discrete event. Almost-universal support — only Linux console partial (depends on framebuffer driver). Restore to `?8h` on exit, always — leaving auto-repeat off pollutes the user's shell session.

Spec citation: DEC VT100 (DECARM) / xterm-ctlseqs

Parameters

Examples

printf '\033[?8l'   # turn OFF auto-repeat for the duration of this TUI\ntrap 'printf "\\033[?8h"' EXIT   # restore on any exit\n# … game loop …

import sys, atexit\nsys.stdout.write('\x1b[?8l')   # roguelike: one move per keypress\natexit.register(lambda: sys.stdout.write('\x1b[?8h'))

fmt.Print("\x1b[?8l")\ndefer fmt.Print("\x1b[?8h")   // always restore

process.stdout.write('\x1b[?8l')\nprocess.on('exit', () => process.stdout.write('\x1b[?8h'))

printf("\x1b[?8l");\natexit_set_restore("\x1b[?8h");   /* paired restore is non-optional */

Terminal support

xterm

yes

Linux console (fbcon)

partial

macOS Terminal.app

yes

iTerm2

yes

Windows Terminal

yes

cmd.exe / ConPTY

partial

kitty

yes

alacritty

yes

WezTerm

yes

Ghostty

yes

GNOME Terminal

yes

Konsole

yes

tmux

no

GNU screen

no

Related sequences

• XTMODKEYS — Modify keyboard reporting (CSI > Pp ; Pv m)
• DECKPAM / DECKPNM — Keypad application / numeric mode (ESC = / ESC >)
• DECSET ?2004 — Bracketed paste mode
• DECSTR — Soft terminal reset