- input-mode #!optional modeprocedure
Sets the termbox input mode. Termbox has two input modes:<br/>
- esc input mode: When ESC sequence is in the buffer and it doesn't match any known ESC sequence.
- alt input mode: When ESC sequence is in the buffer and it doesn't match any known sequence => ESC enables mod-alt modifier for the next keyboard event.
Returns the current mode if node mode is given.