exit - cause normal program termination
void exit(int status));
The exit() function causes normal program termination and
the value of status is returned to the parent. All func-
tions registered with atexit() and on_exit() are called in
the reverse order of their registration, and all open
streams are flushed and closed.
The exit() function does not return.
SVID 3, POSIX, BSD 4.3, ISO 9899
_exit(2), atexit(3), on_exit(3)