showkey(1) on Linux
The text 01ad2da212f6, as Debian 9 (Stretch), Debian 8 (Jessie), Debian 7 (Wheezy), Debian 6.0 (Squeeze) shipped it.
examine the codes sent by the keyboard
Flags it lists
-
--ascii -
--help -
--keycodes -
--scancodes -
-a -
-h -
-k -
-s