unixdev.net


Switch to SpeakEasy.net DSL

The Modular Manual Browser

Home Page
Manual: (OpenBSD-5.7)
Page:
Section:
Apropos / Subsearch:
optional field

_EXIT(2)                    BSD System Calls Manual                   _EXIT(2)

NAME
     _exit, _Exit -- terminate the calling process

SYNOPSIS
     #include <&lt;unistd.h>&gt;

     void
     _exit(int status);

     #include <&lt;stdlib.h>&gt;

     void
     _Exit(int status);

DESCRIPTION
     The _exit() and _Exit() functions terminate a process with the following
     consequences:

     o   All threads in the process are terminated.

     o   All open file descriptors 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 status is set as defined by
         wait(2).  (Note that typically only the lower 8 bits of status are
         passed on to the parent, thus negative values have less meaning.)

     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 and SIGCONT sig-
         nals 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
         terminal, 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., and then calls _exit().

RETURN VALUES
     _exit() and _Exit() can never return.

SEE ALSO
     fork(2), intro(2), sigaction(2), wait(2), exit(3), sysexits(3)

STANDARDS
     The _exit() function conform to IEEE Std 1003.1-2008 (``POSIX.1'').  The
     _Exit() function conforms to ISO/IEC 9899:1999 (``ISO C99'').

HISTORY
     An exit() system call first appeared in Version 1 AT&T UNIX.  It accepts
     the status argument since Version 2 AT&T UNIX.  An _exit() variant first
     appeared in Version 7 AT&T UNIX.  The _Exit() function appeared in
     OpenBSD 3.6.

BSD                             March 27, 2017                             BSD