_exit - terminate the current process
void _exit(int status);
_exit terminates the calling process immediately. Any
open file descriptors belonging to the process are closed;
any children of the process are inherited by process 1,
init, and the process's parent is sent a SIGCHLD
status is returned to the parent process as the
process's exit status, and can be collected using one of the
wait family of calls.
_exit never returns.
SVr4, SVID, POSIX, X/OPEN, BSD 4.3
_exit does not call any functions registered with the
ANSI C atexit function and does not flush standard
I/O buffers. To do these things, use
fork(2), execve(2), waitpid(2),
wait4(2), kill(2), wait(2),