https://docs.oracle.com/cd/E86824_01/html/E54767/flushinp-3xcurses.html
flushinp - man pages section 3: Curses Library Functions
flushinp - discard type-ahead characters The flushinp () function discards (flushes) any characters in the input buffer associated with the current screen.
man pagessectioncurseslibraryfunctions