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

NAME

       exit - cause normal program termination

SYNOPSIS

       #include <stdlib.h>

       void exit(int status);

DESCRIPTION

       The  exit()  function  causes  normal  program termination and the the value of status & 0377 is returned to the parent (see wait(2)).  All
       functions 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 ter-
       mination, respectively.

RETURN VALUE

       The exit() function does not return.

CONFORMING TO

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

NOTES

       During the exit processing, it is possible to register additional functions with atexit() and on_exit().  Always the last-registered  func-
       tion  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 <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() 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 signal, 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 ALSO

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

								    2001-11-17								   EXIT(3)