_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 descrip‐
       tors 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  pro‐
       cesses, signals sent, and so on, 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 3.74 of the Linux man-pages project.  A  description  of  the
       project,  information  about  reporting  bugs, and the latest version of this page, can be
       found at http://www.kernel.org/doc/man-pages/.



Linux                                       2010-09-20                                   _EXIT(2)