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Thread: Problems reading a file API

  1. #1

    Thread Starter
    Don't Panic! Ecniv's Avatar
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    Problems reading a file API

    Hi,

    I always seem to get errors with the APIs... sigh.

    Right, yesterday code like this worked fine. Then I got a corrupted mdb with the code in and had to re-write it to the below.

    The code below doesn't read the file. It's erroring with last dll error 5 (access denied) which is very weird as I have a segment of test code that I copied this from and that works.

    So I must have missed something that is holding that file open.
    Any ideas?


    Code is to read byte by byte, find the vblf that doesn't have a vbcr before it and insert the vbcr, then output to a new file with the original name. Due to my vba code later to read the file and it failing due to no vbcrlf - original text file from a linux system I think...


    Code:
                strFNSrc = strFN & "_Orig.txt"
                Name strFN As strFNSrc
                
                lngFH_Dest = apiFileCreate(strFN, FileDA_Generic_Read, FileSM_Read Or FileSM_Write, ByVal 0&, FileCD_OpenAlways, FileAtt_Normal, 0)
                lngFH_Src = apiFileCreate(strFNSrc, FileDA_Generic_Write, FileSM_Read Or FileSM_Write, ByVal 0&, FileCD_OpenAlways, FileAtt_Normal, 0)
                
                If lngFH_Src <> -1 And lngFH_Dest <> -1 Then
            
                    lngBytesToRead = 4096
                    lngBytesRed = lngBytesToRead
                    
                    'dblFileSize = GetTheFileSizeAPI(lngFH_Src)
                    
                    Do Until lngBytesRed < lngBytesToRead
                        ReDim aryBuffer(lngBytesToRead)
                        ReDim aryNewBuffer(lngBytesToRead + 512)
                    
                        lngRes = apiFileRead(lngFH_Src, aryBuffer(0), lngBytesToRead, lngBytesRed, 0)
                        If lngRes = 0 Then Debug.Print Err.LastDllError
                        lngBytesToWrite = 0
                        
                        If lngBytesRed > 0 Then
                            For lngL = 0 To lngBytesRed - 1
                            
                                If aryBuffer(lngL) = 10 And Not blnPrevCR Then
                                    aryNewBuffer(lngBytesToWrite) = 13
                                    lngBytesToWrite = lngBytesToWrite + 1
                                    aryNewBuffer(lngBytesToWrite) = aryBuffer(lngL)
                                Else
                                    aryNewBuffer(lngBytesToWrite) = aryBuffer(lngL)
                                End If
                                lngBytesToWrite = lngBytesToWrite + 1
                            Next
                        Else
                            txtProgress = Format(Now, "hh:nn:ss") & " - Failed to copy data file" & vbCrLf & txtProgress
                        End If
                        
                        lngRes = apiFileWrite(lngFH_Dest, aryNewBuffer(0), lngBytesToWrite, lngBytesWritten, 0)
    
    '---- store how much has been processed
                        dblFileDone = dblFileDone + lngBytesRed
                        
                        PercBar boxPerc, txtProgress, dblFileDone, dblFileSize
                    Loop
                    
                    lngRes = apiCloseHandle(lngFH_Src)
                    lngRes = apiCloseHandle(lngFH_Dest)
                End If
            End If

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  2. #2

    Thread Starter
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    Re: Problems reading a file API

    Just to add, the file I am copying and the code that I copied this from will read the file when asked to. It just doesn't here in this code.


    What am I missing?


    BOFH Now, BOFH Past, Information on duplicates

    Feeling like a fly on the inside of a closed window (Thunk!)
    If I post a lot, it is because I am bored at work! ;D Or stuck...
    * Anything I post can be only my opinion. Advice etc is up to you to persue...

  3. #3

    Thread Starter
    Don't Panic! Ecniv's Avatar
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    Re: Problems reading a file API

    This works... when in a module and called via immediates window.


    Code:
    Public Sub PreScanFile(ByVal strFileName As String, ByVal blnEraseCopy As Boolean)
        
        Dim strFN As String
        Dim strFNOrig As String
        
        Dim lngRes As Long
        
        Dim lngFHSrc As Long
        Dim lngBytesToRead As Long
        Dim lngBytesRed As Long
        Dim aryBuffer() As Byte
        
        Dim lngFHDest As Long
        Dim lngBytesToWrite As Long
        Dim lngBytesWritten As Long
        Dim aryNewBuffer() As Byte
        
        Dim lngL As Long
        Dim blnPrevCR As Boolean
    
        
        strFN = strFileName
        strFNOrig = strFileName & "Orig.txt"
        
        Name strFN As strFNOrig
        
        
        lngFHSrc = apiFileCreate(strFNOrig, FileDA_Generic_Read, FileSM_Read Or FileSM_Write, ByVal 0&, FileCD_OpenAlways, FileAtt_Normal, 0)
        lngFHDest = apiFileCreate(strFN, FileDA_Generic_Write, FileSM_Read Or FileSM_Write, ByVal 0&, FileCD_OpenAlways, FileAtt_Normal, 0)
    
        If (lngFHSrc <> -1) And (lngFHDest <> -1) Then
            Debug.Print "Source : " & lngFHSrc
            Debug.Print "Dest : " & lngFHDest
            
            lngBytesToRead = 4096
            
            ReDim aryBuffer(lngBytesToRead)
            ReDim aryNewBuffer(lngBytesToRead + 512)
            lngBytesRed = lngBytesToRead
            blnPrevCR = False
            
            Do Until lngBytesRed < lngBytesToRead
                lngRes = apiFileRead(lngFHSrc, aryBuffer(0), lngBytesToRead, lngBytesRed, 0)
            
                If lngBytesRed > 0 Then
                    lngBytesToWrite = 0
                    
                    For lngL = 0 To lngBytesRed - 1
                        
                        If aryBuffer(lngL) = 10 And Not blnPrevCR Then
                            aryNewBuffer(lngBytesToWrite) = 13
                            lngBytesToWrite = lngBytesToWrite + 1
                        End If
                        aryNewBuffer(lngBytesToWrite) = aryBuffer(lngL)
                        lngBytesToWrite = lngBytesToWrite + 1
                        blnPrevCR = aryBuffer(lngL) = 13 'vbcr
                    Next
                    
                    
                    lngRes = apiFileWrite(lngFHDest, aryNewBuffer(0), lngBytesToWrite, lngBytesWritten, 0)
                End If
            Loop
            
            
            lngRes = apiCloseHandle(lngFHDest)
            lngRes = apiCloseHandle(lngFHSrc)
        
        End If
    
        If blnEraseCopy Then Kill strFNOrig
        
    End Sub

    No idea why this works and the other doesn't...

    BOFH Now, BOFH Past, Information on duplicates

    Feeling like a fly on the inside of a closed window (Thunk!)
    If I post a lot, it is because I am bored at work! ;D Or stuck...
    * Anything I post can be only my opinion. Advice etc is up to you to persue...

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