QUESTION:
Hello,
I have a DBF file an I need to open it. I have VFP9.0 and when I try to open it I get a message suc as:
"Memo file C:\....\myfile.fpt is missing or is invalid."
Is there a way to open this file?
ANSWER:
You might also recover your memo file if problem is in next memo block pointer (get a backup and use at your own risk - yani sorumluluk kabul etmem:)
close data all
m.lcDBF = "c:\mypath\myTable.dbf"
RepairMemo(Forceext(m.lcDBF,'FPT'))
Function RepairMemo
* RepairMemo
* Simply fixes next block pointer, blocksize and filesize
Lparameters tcMemoFilename
Local handle, lnFileSize, lnNextBlockPointer, lnBlockSize, lnFirstBlock, lnCalculatedFileSize
handle=Fopen(tcMemoFilename,12) && Opened readwrite
lnFileSize = Fseek(handle,0,2) && Get file size
With This
* Read header info
lnNextBlockPointer = ReadBytes(handle, 0,4,.T.) && Stored in left-to-right format
lnBlockSize = ReadBytes(handle, 6,2,.T.) && Stored in left-to-right format
* Specific to me - no blocksize setting to something other than default 0x40
If lnBlockSize # 0x40
WriteBytes(handle, 6,2,0x40,.T.)
lnBlockSize=0x40
Endif
*
lnFirstBlock = Ceiling(512/lnBlockSize) && Possible min lnNextblockpointer
lnCalculatedFileSize = lnNextBlockPointer*lnBlockSize
* Fix if needs repair
If !(lnFileSize >= 512 ;
and lnNextBlockPointer >= lnFirstBlock ;
and lnCalculatedFileSize >= lnFileSize) && Memo needs repair
lnNextBlockPointer = Max(lnNextBlockPointer, lnFirstBlock)
lnFileSize = lnNextBlockPointer * lnBlockSize
WriteBytes(handle, 0,4,lnNextBlockPointer,.T.) && Fix next block pointer
=Fchsize(handle, lnFileSize) && Fix filesize
Endif
Endwith
=Fclose(handle)
Function WriteBytes
Lparameters tnHandle, tnPos, tnSize, tnNumber, tlLR
Local lcString, lnLowDword, lnHighDword,ix
lcString=''
If tlLR
For ix=tnSize-1 To 0 Step -1
lcString=lcString+Chr(tnNumber/256^ix%256)
Endfor
Else
For ix=0 To tnSize-1
lcString=lcString+Chr(tnNumber/256^ix%256)
Endfor
Endif
=Fseek(tnHandle, tnPos,0) && Go to pos
Return Fwrite(tnHandle,lcString)
Function ReadBytes
Lparameters tnHandle, tnPos, tnSize, tlLR
Local lcString, lnRetValue,ix
=Fseek(tnHandle, tnPos,0) && Go to pos
lcString = Fread(tnHandle, tnSize) && Read tnSize bytes
lnRetValue = 0
For ix=0 To tnSize-1 && Convert to a number
lnRetValue = lnRetValue + Asc(Substr(lcString,ix+1)) * ;
iif(tlLR,256^(tnSize-1-ix),256^ix)
Endfor
Return Int(lnRetValue)
