Set the terminal so that characters may or may not be echoed on
    the terminal screen. This mode of single-character input is only
    supported with Curses.
    Format
      #include  <curses.h>
      void echo  (void);
      void noecho  (void);
1 – Description
    The noecho function may be helpful when accepting input from the
    terminal screen with wgetch and wgetstr; it prevents the input
    characters from being written onto the screen.