INFO: AllocConsole() Necessary to Get Valid Handles

Last reviewed: May 7, 1997
Article ID: Q89750

The information in this article applies to:

Microsoft Win32 Application Programming Interface (API) included with: - Microsoft Windows NT versions 3.1, 3.5, 3.51, 4.0

If a graphical user interface (GUI) application redirects a standard handle, such as stderr or stdout, and then spawns a child process, the output of the child process will not be seen unless the AllocConsole() application programming interface (API) is called by the parent before spawning the child.

If an application spawns a child process without calling AllocConsole() first, then a new console output window is created for the child. The child's console window appears on the screen and the GUI application is not be able to control this window (for example, it cannot minimize the child window). In addition, users can terminate the child process by choosing Close from the console window's Control (system) menu. This causes users to think that only the window is closed, when in actuality, the entire application is terminated. This can cause the user to lose data in the console window.

Keywords : BseCon kbprg
Version : 3.1 3.5 3.51 4.0
Issue type : kbinfo

THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY.

Last reviewed: May 7, 1997
© 1998 Microsoft Corporation. All rights reserved. Terms of Use.