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exit(2)			      System Calls Manual		       exit(2)

NAME
       exit, _exit - terminate process

SYNOPSIS
       #include	<unistd.h>

       void _exit(int status);

MT-LEVEL
       _exit() is Async-Signal-Safe

DESCRIPTION
       _exit() terminates the calling process with the following consequences:

	      All  of  the  file  descriptors  open in the calling process are
	      closed.

	      A	SIGCHLD	 signal	 is  sent  to  the  calling  process's	parent
	      process.

	      If the parent process of the calling process has "not" specified
	      the SA_NOCLDWAIT flag (see sigaction(2)),

		 the calling process is	transformed into a  "zombie  process."
		 A  zombie  process  is	a process that only occupies a slot in
		 the process table.  It	has no other space allocated either in
		 user  or  kernel space.  The process table slot that it occu-
		 pies is partially overlaid with time  accounting  information
		 (see <sys/proc.h>) to be used by the times function.

		 If  the  parent  process  of the calling process is executing
		 wait(2) or waitpid(2),	then it	is  notified  of  the  calling
		 process's  termination	and the	low-order eight	bits of	status
		 are made available to it.

		 If the	parent process of the calling process is not executing
		 a  wait(2)  or	 waitpid(2), status is saved for return	to the
		 parent	process	whenever the parent process executes an	appro-
		 priate	subsequent wait(2) or

		 waitpid(2).

	    Otherwise, if the parent process of	the calling process has	speci-
	    fied the SA_NOCLDWAIT flag,

		 status	is unavailable to the parent.

	    The	parent process ID of all of  the  calling  process's  existing
	    child  processes and zombie	processes is set to 1.	This means the
	    initialization process (see	intro(2)) inherits each	of these  pro-
	    cesses.

	    Each  attached  shared memory segment is detached and the value of
	    shm_nattach	in the data structure associated with its shared  mem-
	    ory	 identifier  is	 decremented by	1.  Memory mappings created in
	    the	process	are unmapped.

	    For	each semaphore for which the calling process has set a	semadj
	    value  (see	semop(2)), that	semadj value is	added to the semval of
	    the	specified semaphore.

	    If the process has process,	text or	data locks, an unlock is  per-
	    formed (see	plock(3C) and memcntl(2)).

	    All	 open  named semaphores	in the process are closed as if	by ap-
	    propriate calls to sem_close(3R).  All open	message	queues in  the
	    process  are  closed  as  if by appropriate	calls to mq_close(3R).
	    Any	outstanding asynchronous I/O operations	may be cancelled.

	    An accounting record is written on the accounting file if the sys-
	    tem's accounting routine is	enabled	(see acct(2)).

	    If	the  process  is  a controlling	process, SIGHUP	is sent	to the
	    foreground process group of	its controlling	terminal and its  con-
	    trolling terminal is deallocated.

	    If	the  calling  process  has  any	stopped	children whose process
	    group will be orphaned when	the calling process exits, or  if  the
	    calling  process  is  a member of a	process	group that will	be or-
	    phaned when	the calling process exits, that	process	group will  be
	    sent SIGHUP	and SIGCONT signals.

SEE ALSO
       acct(2),	  intro(2),   memcntl(2),  semop(2),  sigaction(2),  times(2),
       wait(2),	waitpid(2), exit(3C), plock(3C), mq_close(3R),	sem_close(3R),
       signal(5)

				  9 Jul	1994			       exit(2)

NAME | SYNOPSIS | MT-LEVEL | DESCRIPTION | SEE ALSO

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