_exit(2) [netbsd man page]

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

NAME

     _Exit, _exit -- terminate the calling process

LIBRARY

     Standard C Library (libc, -lc)

SYNOPSIS

     #include <stdlib.h>

     void
     _Exit(int status);

     #include <unistd.h>

     void
     _exit(int status);

DESCRIPTION

     The _Exit() and _exit() functions are equivalent.	They each terminate a process with the following consequences:

     o	 All of the descriptors 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(2) call or catches the SIGCHLD signal, it is notified of the calling
	 process's termination and 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, and 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 VALUES

     _Exit() and _exit() can never return.

SEE ALSO

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

STANDARDS

     The _exit() function conforms to ISO/IEC 9945-1:1990 (``POSIX.1'').  The _Exit() function conforms to ISO/IEC 9899:1999 (``ISO C99'').

BSD
								  April 23, 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)