when i use ps -ef command,
there is some ? under TTY column,
what does it stand for??
And i want to disable user to access console application such as firewall-config, what should i do??
thank you.
the ? mark means exactly that. it is not associated with a terminal so tty is unknown.
if you dont want a user to run a program change the permissions/owner/group on it.
man chmod/chown/chgrp