showkey

View keycodes in decimal

$ sudo showkey

$ sudo showkey -s

$ sudo showkey -k

$ sudo showkey -a

showkey [options]

showkey displays the keycode of pressed keys on the keyboard. This is useful for debugging keyboard-related issues, key remapping, and understanding keyboard input at a low level.
The program runs until 10 seconds pass without any key press, or until Ctrl+D is pressed (in ASCII mode).

-s, --scancodes

Display scancodes in hexadecimal

Display keycodes in decimal (default)

Display keycodes in ASCII, decimal, and hexadecimal

Display help message

Must be run as root or with sudo. Only works on the Linux console, not in terminal emulators under X11 or Wayland. The keyboard becomes unusable for normal input while running.

loadkeys(1), dumpkeys(1), xmodmap(1)