GetFileSize

[Scott Turchin]

Can anyone see any obvious problem here?
It returns zero unless I execute the code at the bottom of the function, but I'd rather use the API call...

Function GetSizeOfFile(FileSpec As String) As Long
Local l_zFileSpec       As Asciiz * 255
Local l_hFindFile       As Long
Local lpFileSizeHigh    As Long
Local l_Result          As Long
Local finddata          As WIN32_FIND_DATA

l_zFileSpec = FileSpec

finddata.dwFileAttributes = %FILE_ATTRIBUTE_DIRECTORY
'Or %FILE_ATTRIBUTE_NORMAL Or %FILE_ATTRIBUTE_ARCHIVE Or %FILE_ATTRIBUTE_READONLY
l_hFindFile = FindFirstFile(l_zFileSpec, finddata)

If l_hFindFile = %INVALID_HANDLE_VALUE Then
   Function = %INVALID_HANDLE_VALUE  'Check for it when pulling file size from main program otherwise wrong file size!!
   MsgBox "Invalid File Handle",%MB_ICONSTOP,CCS
   Exit Function
End If

l_Result = GetFileSize(ByVal l_hFindFile, lpFileSizeHigh)
Function = lpFileSizeHigh
FindClose l_hFindFile

Exit Function
'Of course this works:
l_hFindFile = FreeFile
Open filespec For Input As #l_hFindFile
Function = Lof(l_hFindFile)
Close l_hFindFile
End Function

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Scott
mailto:[email protected][email protected]</A>

[Semen Matusovski]

Scott --
I modified you code.

   #Compile Exe
   #Register None
   #Dim All
   #Include "WIN32API.INC"

   Function GetSizeOfFile(FileSpec As Asciiz) As Double
      Local FindData As WIN32_FIND_DATA, l_hFindFile As Long
      l_hFindFile = FindFirstFile(FileSpec, FindData)
      If l_hFindFile = %INVALID_HANDLE_VALUE Then Function = -1 Else _
         Function = FindData.nFileSizeHigh * &H100000000 + FindData.nFileSizeLow: _
                    FindClose l_hFindFile
   End Function

   Function PbMain
      MsgBox Str$(GetSizeOfFile("C:\IO.SYS"))
   End Function

[This message has been edited by Semen Matusovski (edited February 26, 2000).]

[Scott Turchin]

I don't understand it, but it works beautiful, thanks!


Scott

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Scott
mailto:[email protected][email protected]</A>

[Semen Matusovski]

Scott --
l_hFindFile = FindFirstFile(FileSpec, FindData) - reads information about file into WIN32_FIND_DATA structure.

This structure has all necessary parameters, including the file size.
Because for files more than 4 Mb, one DWORD is not enough,
a length is stored in two DWORDs (integer value in 8 bytes).
So, total size is
nFileSizeHigh * 256 * 256 * 256 * 256 + nFileSizeLow

[This message has been edited by Semen Matusovski (edited February 26, 2000).]

[LRantanen]

Scott,

although Semen already gave you a good solution w/ less code, I post this just to show how it is done using GetFileSize.

Lasse Rantanen
[email protected]

FUNCTION GetSizeOfFile(FileSpec AS STRING) AS DWORD
    LOCAL l_zFileSpec       AS ASCIIZ * 255
    LOCAL l_hFindFile       AS DWORD
    LOCAL l_dwSize          AS DWORD
    LOCAL l_dwSizeLow       AS DWORD
    LOCAL l_dwSizeHigh      AS DWORD
 
    l_zFileSpec = FileSpec
 
    l_hFindFile = CreateFile(BYVAL VARPTR(l_zFileSpec), _
                             %GENERIC_READ, _
                             %FILE_SHARE_READ, _
                             BYVAL %NULL, _
                            %OPEN_EXISTING, _
                            %FILE_FLAG_NO_BUFFERING OR %FILE_FLAG_OVERLAPPED, _
                            BYVAL %NULL)
 
    IF (l_hFindFile = %INVALID_HANDLE_VALUE) THEN
        MSGBOX "Failed to open " + FileSpec + $CrLf + $CrLf +_
               "ERROR " + STR$(GetLastError())
        FUNCTION = -1
        EXIT FUNCTION
    END IF
 
    l_dwSizeLow = GetFileSize(l_hFindFile, BYVAL VARPTR(l_dwSizeHigh))
    IF ((l_dwSizeLow = &H0FFFFFFFF) AND (GetLastError() <> %NO_ERROR)) THEN
        MSGBOX "GetFileSize failed, error " + STR$(GetLastError())
        FUNCTION = -1
        EXIT FUNCTION
    END IF
    CloseHandle l_hFindFile
    FUNCTION = MAKDWD(l_dwSizeLow, l_dwSizeHigh)
  
END FUNCTION

[Semen Matusovski]

Function as DWORD ?
MAKDWD(l_dwSizeLow, l_dwSizeHigh) ?
Test your function on big files - 5-6 Gb.
File size is storing in two DWORD variables (2 * 4 bytes).
It's Quad without sign.

[This message has been edited by Semen Matusovski (edited February 26, 2000).]

[LRantanen]

Of course I had to slip an error to my sample. Part of that error is also in Semen's code.

The return type of the GetSizeOfFile function should be QUAD so that those huge file sizes will be reported correctly.

And in my sample, line FUNCTION = MAKDWD(... should read e.g.

   Function = l_dwSizeHigh * &H100000000 + l_dwSizeLow

as in Semen's sample.

Sorry about this

Lasse Rantanen
[email protected]

[Semen Matusovski]

Lasse --
I declared function as DOUBLE, not as DWORD.

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[LRantanen]

Semen,

sorry about that. I also seem to have problems reading carefully. I was narrow mindedly only thinking about integers.

Lasse Rantanen
[email protected]

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[Scott Turchin]

Awesome, thank you both

The &H10000000 part confused me, think I got it now!


Scott

------------------
Scott
mailto:[email protected][email protected]</A>