exit(3) [mojave man page]

EXIT(3) 						   BSD Library Functions Manual 						   EXIT(3)

NAME

     exit, _Exit -- perform normal program termination

LIBRARY

     Standard C Library (libc, -lc)

SYNOPSIS

     #include <stdlib.h>

     void
     exit(int status);

     void
     _Exit(int status);

DESCRIPTION

     The exit() and _Exit() functions terminate a process.

     Before termination, exit() performs the following functions in the order listed:

	   1.	Call the functions registered with the atexit(3) function, in the reverse order of their registration.

	   2.	Flush all open output streams.

	   3.	Close all open streams.

	   4.	Unlink all files created with the tmpfile(3) function.

     The _Exit() function terminates without calling the functions registered with the atexit(3) function, and may or may not perform the other
     actions listed.  Both functions make the low-order eight bits of the status argument available to a parent process which has called a
     wait(2)-family function.

     The C Standard (ISO/IEC 9899:1999 (``ISO C99'')) defines the values 0, EXIT_SUCCESS, and EXIT_FAILURE as possible values of status.  Cooper-
     ating processes may use other values; in a program which might be called by a mail transfer agent, the values described in sysexits(3) may be
     used to provide more information to the parent process.

     Note that exit() does nothing to prevent bottomless recursion should a function registered using atexit(3) itself call exit().  Such func-
     tions must call _Exit() instead (although this has other effects as well which may not be desired).

RETURN VALUES

     The exit() and _Exit() functions never return.

SEE ALSO

     _exit(2), wait(2), atexit(3), intro(3), sysexits(3), tmpfile(3)

STANDARDS

     The exit() and _Exit() functions conform to ISO/IEC 9899:1999 (``ISO C99'').

BSD
								 September 9, 2002							       BSD

_EXIT(2)						     Linux Programmer's Manual							  _EXIT(2)

NAME

       _exit, _Exit - terminate the calling process

SYNOPSIS

       #include <unistd.h>

       void _exit(int status);

       #include <stdlib.h>

       void _Exit(int status);

   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

       _Exit():
	   _XOPEN_SOURCE >= 600 || _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L;
	   or cc -std=c99

DESCRIPTION

       The  function  _exit()  terminates  the	calling process "immediately".	Any open file descriptors belonging to the process are closed; any
       children of the process are inherited by process 1, init, and the process's parent is sent a SIGCHLD signal.

       The value status is returned to the parent process as the process's exit status, and can be collected using one of the  wait(2)	family	of
       calls.

       The function _Exit() is equivalent to _exit().

RETURN VALUE

       These functions do not return.

CONFORMING TO

       SVr4, POSIX.1-2001, 4.3BSD.  The function _Exit() was introduced by C99.

NOTES

       For a discussion on the effects of an exit, the transmission of exit status, zombie processes, signals sent, etc., see exit(3).

       The function _exit() is like exit(3), but does not call any functions registered with atexit(3) or on_exit(3).  Whether it flushes standard
       I/O buffers and removes temporary files created with tmpfile(3) is implementation-dependent.  On the other hand, _exit()  does  close  open
       file  descriptors,  and this may cause an unknown delay, waiting for pending output to finish.  If the delay is undesired, it may be useful
       to call functions like tcflush(3) before calling _exit().  Whether any pending I/O is canceled, and which pending I/O may be canceled  upon
       _exit(), is implementation-dependent.

       In  glibc  up  to  version 2.3, the _exit() wrapper function invoked the kernel system call of the same name.  Since glibc 2.3, the wrapper
       function invokes exit_group(2), in order to terminate all of the threads in a process.

SEE ALSO

       execve(2), exit_group(2), fork(2), kill(2), wait(2), wait4(2), waitpid(2), atexit(3), exit(3), on_exit(3), termios(3)

COLOPHON

       This page is part of release 3.27 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								    2010-09-20								  _EXIT(2)