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

       exit - cause normal process termination

       #include	<stdlib.h>

       void exit(int status);

       The  exit() function causes normal process termination and the value of
       status _	0377 is	returned to the	parent (see wait(2)).

       All functions registered	with atexit(3) and on_exit(3) are  called,  in
       the  reverse  order  of their registration.  (It	is possible for	one of
       these functions to use atexit(3)	or on_exit(3)  to  register  an	 addi-
       tional  function	 to be executed	during exit processing;	the new	regis-
       tration is added	to the front of	the list of functions that  remain  to
       be  called.)  If	one of these functions does not	return (e.g., it calls
       _exit(2), or kills itself with a	signal), then none  of	the  remaining
       functions is called, and	further	exit processing	(in particular,	flush-
       ing of stdio(3) streams)	is abandoned.  If a function has  been	regis-
       tered  multiple	times using atexit(3) or on_exit(3), then it is	called
       as many times as	it was registered.

       All open	stdio(3) streams are flushed and  closed.   Files  created  by
       tmpfile(3) are removed.

       The  C standard specifies two constants,	EXIT_SUCCESS and EXIT_FAILURE,
       that may	be passed to exit() to	indicate  successful  or  unsuccessful
       termination, respectively.

       The exit() function does	not return.

   Multithreading (see pthreads(7))
       The exit() function uses	a global variable that is not protected, so it
       is not thread-safe.

       SVr4, 4.3BSD, POSIX.1-2001, C89,	C99.

       It is undefined what happens if one of the functions  registered	 using
       atexit(3)  and on_exit(3) calls either exit() or	longjmp(3).  Note that
       a call to execve(2) removes registrations created using	atexit(3)  and

       The  use	of EXIT_SUCCESS	and EXIT_FAILURE is slightly more portable (to
       non-UNIX	environments) than the use 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 _sysexits.h_.

       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(2) 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 is  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.  See setpgid(2) for an	explanation of
       orphaned	process	groups.

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

       This page is part of release 3.74 of the	Linux  man-pages  project.   A
       description  of	the project, information about reporting bugs, and the
       latest	 version    of	  this	  page,	   can	   be	  found	    at

Linux				  2014-03-25			       EXIT(3)


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