To establish a session under the X Window System, execute ttsession either without arguments (which takes the display from the $DISPLAY
environment variable) or specify the display with the -d parameter as follows:
ttsession -d :0
When ttsession is invoked, it immediately forks and the parent copy exits; the process managing the session executes in the background. The session is registered as a property, named by TT_SESSION
on the root window of screen 0; the host and port number is given for communication with the process managing the session.