A fair amount of work is required to configure a serial port for use. Much more work would be required to set up a psuedo terminal and that work needs to be done on the other end of the connection. The fact that you seem to be getting output would suggest that you are attempting to use a serial port that is already in use. You can output on serial device already in use... programs like wall do that. But you probably have a shell already trying to read from the terminal. Your whole design seems completely backwards. Deamons cannot suddenly decide that they want to acquire a user. A user needs to decide to converse with a daemon. To do this, a user would run an interactive program that would use IPC to communicate with the daemon.