How to reset a broken TTY?

Usually, running reset resets the terminal. Some key bindings from .inputrc might be lost, though.

Run echo ^v^o, that is echo and then Ctrl-v and then Ctrl-o, Enter. You will not see the Ctrl-v. It will display as echo ^O. Ctrl-v sets it into verbose mode, passing through control characters, and the Ctrl-o will reset the terminal.

You can try the ANSI reset command:

printf "\033c"