20.1.2 Console I/O - kbhit () Return true if a keypress is
waiting to be read. - getch () Read a keypress and return the
resulting character. Nothing is echoed to the console. This call
will block if a keypress is not already available, but will not
wait for Enter to be pressed. If the pressed key was a special
function key, this will return '\xe0'; the next call will return
the keycode. The Control-C keypress cannot be read with this -
getche () Similar to getch(), but the keypress will be echoed if
it represents a printable character. - putch (char) Print the
character char to the console without buffering. - ungetch
(char) Cause the character char to be ``pushed back'' into the
console buffer; it will be the next character read by getch() or
getche(). See About this document... for information on
suggesting changes.