ÿ@SUBJECT:RE: HOW TO KNOW IF IT'S A DBF                               N
Hi JTENDERS !
This is what you asked :
//------------------------------------------------------------------------
// --- Written by PHILL TERRY ---
FUNCTION IsDBF( File2Check )
   LOCAL ItsADBF    := .F.
   LOCAL nChkHdl    := 0
   LOCAL cChkBfr    := " "
   LOCAL cChkLEN    := 1
   LOCAL nByteRead  := 0
   nChkHdl    := FOPEN( File2Check )
   nByteRead  := FREAD( nChkHdl, @cChkBfr, cChkLEN )
   FCLOSE( nChkHdl )
   IF CHR(03) $ cChkBfr .OR.;
      CHR(131) $ cChkBfr
      ItsADBF := .T.
   ENDIF
RETURN ItsADBF
//-------------------------------------------------------------------------
  To check only the FIRST byte of the file.  This is only valid for
Clipper-made .DBF files, too.  That first byte's value could vary for
database files produces by other programs.  The "96" that was included
as "a byte to check" was actually the "year of last update".
Here is a portion of text that I snagged off CI$ that describes a .DBF's
header structure (again, this is specific to Clipper-produced .DBF
files)...
   Table: File description record
   ------------------------------------------------------------------
   Offset      Format         Contents
   ------------------------------------------------------------------
   0           03 or 083h     Signature Byte:
                              03h - (.dbf) with no memo (.dbt) file
                              083h- (.dbf) with memo (.dbt) file
   1           Year           Last update year without century
   2           01 to 12       Month of last update
   3           01 to 31       Day of last update
   4-7         Long           Number of records
   8-9         Word           Location in file where data begins
                              (START)
   10-11       Word           Record length (field sizes plus 1)
   12-31       N/A            Reserved
   ------------------------------------------------------------------
 ... given this, perhaps checking bytes 2-4 (offset 1-3) would be an
idea .. you could see if the date was "reasonable".
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