The function
_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 signal.
The value
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.
The function
_Exit is equivalent to
_exit .
RETURN VALUE
These functions do not return.
CONFORMING TO
SVr4, SVID, POSIX, X/OPEN, BSD 4.3.
The function _Exit() was introduced by C99.
NOTES
For a discussion on the effects of an exit, the transmission of
exit status, zombie processes, signals sent, etc., see
exit(3) . The function
_exit is like exit(), but does not call any functions registered
with the ANSI C
atexit function, nor any registered signal handlers. Whether it flushes
standard I/O buffers and removes temporary files created with
tmpfile(3) is implementation-dependent.
On the other hand,
_exit does close open file descriptors, and this may cause an unknown delay,
waiting for pending output to finish. If the delay is undesired,
it may be useful to call functions like tcflush() before
calling _exit().
Whether any pending I/O is cancelled, and which pending I/O may be
cancelled upon _exit(), is implementation-dependent.
