The keystrokes mapped to signals in line discipline can be viewed by
stty -e. The output is
ALT+Fn keystroke is not in the list. So, is the keystroke handled by TTY driver?
I read that line discipline is part of TTY driver. Is it true? If true, then why the keystroke is not handled by line discipline? What separates line discipline and TTY driver if line discipline is part of TTY driver?