redhat man page for _exit

_EXIT(2)						     Linux Programmer's Manual							  _EXIT(2)

NAME
       _exit, _Exit - terminate the current process

SYNOPSIS
       #include <unistd.h>

       void _exit(int status);

       #include <stdlib.h>

       void _Exit(int status);

DESCRIPTION
       The  function  _exit terminates the calling process "immediately". Any open file descriptors belonging to the process are closed; any chil-
       dren 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.

SEE ALSO
       fork(2), execve(2), waitpid(2), wait4(2), kill(2), wait(2), exit(3), termios(3)

Linux								    2001-11-17								  _EXIT(2)