More importantly, how do you know whether the keystrokes should be displayed at all? For example, take vi. When it starts up, it sets cc.c_lflag &= ~ECHO (bas

More importantly, how do you know whether the keystrokes should be displayed at all? For example, take vi. When it starts up, it sets cc.c_lflag &= ~ECHO (basically like “stty -echo”) so that normal mode commands aren’t printed onscreen. The kernel knows whether ECHO is set, which is why it handles echoing.