EXIT(3) 		   Linux Programmers Manual		      EXIT(3)



NAME
       exit - cause normal process termination

SYNOPSIS
       #include 

       void exit(int status);

DESCRIPTION
       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.

RETURN VALUE
       The exit() function does not return.

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

NOTES
       It  is  undefined what happens if one of the functions registered using
       atexit(3) and on_exit(3) calls either exit() or longjmp(3).

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

       BSD has attempted to standardize exit codes; see the file .

       After  exit(),  the  exit status must be transmitted to the parent pro
       cess.  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  pro
       cess in this process group.

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

COLOPHON
       This  page  is  part of release 3.05 of the Linux man-pages project.  A
       description of the project, and information about reporting  bugs,  can
       be found at http://www.kernel.org/doc/man-pages/.



Linux				  2007-06-12			       EXIT(3)