Q46720: VARPTR(#filenumber) Not Supported in QB 4.x or BC 6.00, 7.00

Article: Q46720
Product(s): See article
Version(s): 4.00 4.00b 4.50
Operating System(s): MS-DOS
Keyword(s): ENDUSER | B_BasicCom | mspl13_basic
Last Modified: 14-DEC-1989

Instead of passing the file number (#n) to the VARPTR function for a
random access file, you may use VARPTR to take the address of the
first variable defined in the FIELD statement to return the address of
the FIELD buffer.

This information applies to Microsoft QuickBASIC Versions 4.00, 4.00b,
and 4.50 for MS-DOS, to Microsoft BASIC Compiler Versions 6.00 and
6.00b for MS-DOS, and to Microsoft BASIC PDS Version 7.00 for MS-DOS.

In QuickBASIC Versions 2.00, 2.01, and 3.00, the VARPTR function can
be passed the file number (#n) of a previously OPENed file. For
sequential access files, VARPTR(#n) then returns the starting address
of the disk I/O buffer assigned to that file number. For random access
files, VARPTR(#n) returns the address of the FIELD buffer assigned to
that file number.

In QuickBASIC Versions 4.00, 4.00b, and 4.50 (and in the BASIC
compiler Versions 6.00 and 6.00b and BASIC PDS 7.00), you cannot use
VARPTR with a file number (#n) as an argument. This feature has been
eliminated. You can now use the FILEATTR function, which returns the
BASIC access mode and the DOS file handle, which may be useful for DOS
file interrupts.

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.

Copyright Microsoft Corporation 1986-2002.