Microsoft KB Archive/22379

PRB: Windows Applications Cannot Share File Handles ID Number: Q22379

2.00 2.03 2.10 3.00 3.10 WINDOWS

Summary:

SYMPTOMS One application initializes a file, and receives the handle of x ‘0005’. The application then takes the handle and places it into global memory. The SetClipboardData function is then called using a format returned by the RegisterClipboard function. A second application then opens the Clipboard and retrieves the handle correctly; however, when the application tries to write to the handle, MS-DOS returns AX=0000, indicating that it did not write any information.

RESOLUTION Applications cannot share file handles. This is a feature of the MS-DOS filing system.

The file handle table is part of each application’s environment; the file handle itself is an offset into this table. Although an offset of 5 might be valid for two applications, the file information at that offset in the respective file handle tables will be very different.

Passing the filename to the second application is recommended.

Additional reference words: TAR60849 2.x 2.00 2.03 2.10 2.x 3.00 3.10 3.x