FoxPro Header Check to Determine if Database Is Corrupt

 Last reviewed: April 30, 1996
Article ID: Q110968
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

When opening a database file (.DBF), FoxPro checks the header for the following five conditions that indicate corruption:

  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 reference words: VFoxWin 3.00 FoxMac FoxDos FoxWin 2.50 2.50a
2.50b table
2.60
KBCategory: kbprg
KBSubcategory: FxprgGeneral

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Last reviewed: April 30, 1996
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