What happens with process when it is run without a controlling terminal? How is that process different from a standard processes? What features does it lose and what does it acquire?
UPDATE #1
The question listed as a possible duplicate: Concept of controlling terminal in Unix doesn't contain the answer. Also that other question is too broad and doesn't mention process qualities at all.
Best Answer
Not much.
Mostly a process without a controlling terminal is not subject to receiving (mostly job control related) signals from terminal events.
These would include
SIGINT
, interrupting the foreground process (group) if the interrupt character is received (usually ^C);SIGTTIN
/SIGTTOU
stopping the process if it tries I/O to the terminal from the background, and;SIGHUP
telling the controlling process (the shell) to terminate, in when the terminal sees a disconnection. (Originally a modem hangup.)The standard has the details if you like.