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EXIT(3)			   Linux Programmer's Manual		       EXIT(3)

       exit - cause normal program termination

       #include	<stdlib.h>

       void exit(int status);

       The exit() function causes normal program termination and the the value
       of status _ 0377	is returned to the parent (see	wait(2)).   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.	Files created by tmpfile() are removed.

       The C standard specifies	two defines EXIT_SUCCESS and EXIT_FAILURE that
       may be passed to	exit() to indicate successful or unsuccessful termina-
       tion, respectively.

       The exit() function does	not return.

       SVID 3, POSIX, BSD 4.3, ISO 9899	(``ANSI	C'')

       During the exit processing, it is possible to register additional func-
       tions with atexit() and on_exit().  Always the last-registered function
       is  removed from	the chain of registered	functions, and invoked.	 It is
       undefined what happens if  during  this	processing  either  exit()  or
       longjmp() is called.

       The  use	of EXIT_SUCCESS	and EXIT_FAILURE is slightly more portable (to
       non-Unix	environments) than that	of 0 and some nonzero value like 1  or
       -1. In particular, VMS uses a different convention.

       BSD  has	 attempted  to	standardize  exit codes	- see the file _sysex-

       After exit(), the  exit	status	must  be  transmitted  to  the	parent
       process.	 There are three cases.	If the parent has set SA_NOCLDWAIT, or
       has set the SIGCHLD handler to SIG_IGN, the status is discarded.	If the
       parent  was  waiting on the child it is notified	of the exit status. In
       both cases the exiting process dies immediately.	If the parent has  not
       indicated  that	it  is	not  interested	in the exit status, but	is not
       waiting,	the exiting process turns into a "zombie"  process  (which  is
       nothing	but a container	for the	single byte representing the exit sta-
       tus) so that the	parent can learn the exit status when it  later	 calls
       one of the wait() functions.

       If  the implementation supports the SIGCHLD signal, this	signal is sent
       to the parent. If the parent has	 set  SA_NOCLDWAIT,  it	 is  undefined
       whether a SIGCHLD signal	is sent.

       If  the	process	 is  a session leader and its controlling terminal the
       controlling terminal of the session, then each  process	in  the	 fore-
       ground process group of this controlling	terminal is sent a SIGHUP sig-
       nal, and	the terminal is	disassociated from this	session,  allowing  it
       to be acquired by a new controlling process.

       If  the	exit of	the process causes a process group to become orphaned,
       and if any member of the	newly-orphaned process group is	stopped,  then
       a  SIGHUP  signal  followed  by	a  SIGCONT signal will be sent to each
       process in this process group.

       _exit(2), wait(2), atexit(3), on_exit(3), tmpfile(3)

				  2001-11-17			       EXIT(3)


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