At least for volume control this would be nice. But it's not really in the spirit of rio, is it...
In Plan 9 keybindings are set via /dev/kbmap (a device!), /sys/lib/kbmap/ has files to map key presses to UTF characters, furthermore it has 2 special files useful for laptops (xkeyboard-config(7) doesn't have equivalent for this!!!):
- mouse-csa maps Ctrl, Start and Alt to 3 mouse buttons;
- mouse-fn maps F1, F2, F3, F4 and F5 to 3 mouse buttons and mouse wheel.
But POSIX systems can't be that simple, first to make UTF characters printable you must install fonts because base systems usually don't have sane fonts (FreeBSD is the only place where I can read russian characters in console), then you must set LANG or LC_ALL environment variable to something.UTF-8 because otherwise it will refuse to print UTF characters, in GNU and BSD world you must also set encoding variable to UTF-8, then you must use X keyboard extension to map key presses to UTF characters, but you still can't map key presses to mouse buttons and volume control, insane!