DOCUMENT:Q110968 03-AUG-2000 [foxpro] TITLE :INFO: FoxPro Header Check to Determine if Table is Corrupt PRODUCT :Microsoft FoxPro PROD/VER:MACINTOSH:2.5b; MS-DOS:2.5,2.5a,2.5b,2.6; WINDOWS:2.5,2.5a,2.5b,2.6,3.0 OPER/SYS: KEYWORDS:kbHWMAC kbvfp kbvfp300 kbDSupport ====================================================================== ------------------------------------------------------------------------------- The information in this article applies to: - Microsoft Visual FoxPro for Windows, version 3.0 - Microsoft FoxPro for Windows, versions 2.5, 2.5a, 2.5b, 2.6 - Microsoft FoxPro for MS-DOS, versions 2.5, 2.5a, 2.5b, 2.6 - Microsoft FoxPro for Macintosh, version 2.5b ------------------------------------------------------------------------------- SUMMARY ======= When opening a database file (.DBF), FoxPro checks the header for the following five conditions that indicate corruption in a table: 1. Is the record length invalid? - Record length <= 1 - Record length > maximum record length 2. Are there no fields? 3. Are there more fields than permitted? 4. Is the number of records < 0? 5. Is the file size invalid? - (Start-of-data + the # of records) * rec. length > file size NOTE: Start-of-data is where the first byte of the first record begins. Additional query words: ====================================================================== Keywords : kbHWMAC kbvfp kbvfp300 kbDSupport Technology : kbHWMAC kbOSMAC kbVFPsearch kbAudDeveloper kbFoxproSearch kbZNotKeyword3 kbFoxPro250bMac kbFoxPro250DOS kbFoxPro250aDOS kbFoxPro250bDOS kbFoxPro260DOS kbFoxPro260 kbFoxPro250 kbFoxPro250a kbFoxPro250b kbVFP300 Version : MACINTOSH:2.5b; MS-DOS:2.5,2.5a,2.5b,2.6; WINDOWS:2.5,2.5a,2.5b,2.6,3.0 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. Copyright Microsoft Corporation 2000.