_exit(2) [mojave man page]

EXIT(2) 						      BSD System Calls Manual							   EXIT(2)

NAME

     _exit -- terminate the calling process

SYNOPSIS

     #include <unistd.h>

     void
     _exit(int status);

DESCRIPTION

     The _exit() function terminates a process, with the following consequences:

     o	 All of the descriptors that were open in the calling process are closed.  This may entail delays; for example, waiting for output to
	 drain.  A process in this state may not be killed, as it is already dying.

     o	 If the parent process of the calling process has an outstanding wait call or catches the SIGCHLD signal, it is notified of the calling
	 process's termination; the status is set as defined by wait(2).

     o	 The parent process-ID of all of the calling process's existing child processes are set to 1; the initialization process (see the DEFINI-
	 TIONS section of intro(2)) inherits each of these processes.

     o	 If the termination of the process causes any process group to become orphaned (usually because the parents of all members of the group
	 have now exited; see ``orphaned process group'' in intro(2)), and if any member of the orphaned group is stopped, the SIGHUP signal and
	 the SIGCONT signal are sent to all members of the newly-orphaned process group.

     o	 If the process is a controlling process (see intro(2)), the SIGHUP signal is sent to the foreground process group of the controlling ter-
	 minal.  All current access to the controlling terminal is revoked.

     Most C programs call the library routine exit(3), which flushes buffers, closes streams, unlinks temporary files, etc., before calling
     _exit().

RETURN VALUE

     _exit() can never return.

SEE ALSO

     fork(2), sigaction(2), wait(2), exit(3)

STANDARDS

     The _exit function is defined by IEEE Std 1003.1-1988 (``POSIX.1'').

4th Berkeley Distribution					   June 4, 1993 					 4th Berkeley Distribution

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)