FileOpen detect already opened file

[hannes08]

Hi Folks,

I have a small GUI application that writes to a text file. This is basically the part of the script:

$fh = FileOpen("Test.txt", 9) ;Append at the end of the File and create the dir structure if it doesn't exist
FilewriteLine($fh, "Bli bla blubb...") ;Write 1 - many lines to the file
FileClose($fh)

So ... sometimes while that application is running, there is another file that does something like this:

$fh = FileOpen("Test.txt", 2) ;Open file, erase the contents
FileClose($fh)

Okay, so basically that is bad, because it results in the first script writing several "NULL"s to the file, so if I try to read that file with another script and _FileReadToArray() it basically exits with RC 2 (Unable to split the file).

So the question is: Can I detect that the first file is already opened by an application?

Maybe I need to mention that the files is stored on a network drive.

Any comments are welcome.

[guinness]

Look at LockFile in my signature.

[Nessie]

Try this:

#Include <WinAPI.au3>

ConsoleWrite(_FileIsUses(@ScriptDir & '\My.pdf') & @CR)

Func _FileIsUses($sFile)

    Local $hFile = _WinAPI_CreateFile($sFile, 2, 2, 0)

    If $hFile Then
        _WinAPI_CloseHandle($hFile)
        Return 0
    EndIf

    Local $Error = _WinAPI_GetLastError()

    Switch $Error
        Case 32 ; ERROR_SHARING_VIOLATION
            Return 1
        Case Else
            Return SetError($Error, 0, 0)
    EndSwitch
EndFunc   ;==>_FileIsUses

[hannes08]

Thanks guys,

I will try both of your solutions and report what I found.

[guinness]

You're welcome.

Nice function Nessie. Using Constants.

#include <WinAPI.au3>

Local $hFileOpen = FileOpen(@ScriptFullPath, $FO_READ)
ConsoleWrite(_FileIsUses(@ScriptFullPath) & @CRLF)
FileClose($hFileOpen)

Func _FileIsUses($sFilePath) ; By Nessie. Modified by guinness.
    Local Const $hFileOpen = _WinAPI_CreateFile($sFilePath, $CREATE_ALWAYS, $FILE_SHARE_WRITE)
    If $hFileOpen Then
        _WinAPI_CloseHandle($hFileOpen)
         Return False
    EndIf

    Local $fReturn = False
    If _WinAPI_GetLastError() = 32 Then $fReturn = True
    Return $fReturn
EndFunc   ;==>_FileIsUses

[Nessie]

You're welcome.

Nice function Nessie. Using Constants.

#include <WinAPI.au3>

Local $hFileOpen = FileOpen(@ScriptFullPath, $FO_READ)
ConsoleWrite(_FileIsUses(@ScriptFullPath) & @CRLF)
FileClose($hFileOpen)

Func _FileIsUses($sFilePath) ; By Nessie. Modified by guinness.
    Local Const $hFileOpen = _WinAPI_CreateFile($sFilePath, $CREATE_ALWAYS, $FILE_SHARE_WRITE)
    If $hFileOpen Then
        _WinAPI_CloseHandle($hFileOpen)
         Return False
    EndIf

    Local $fReturn = False
    If _WinAPI_GetLastError() = 32 Then $fReturn = True
    Return $fReturn
EndFunc   ;==>_FileIsUses

Thanks for the compliment, but this isn't a function of mine.

I have this snippet in my snippet folder, but unfortunatly i don't know the author

Edit:

The author seems to be Yashied and is here.

Edited March 4, 2013 by Nessie

[StefanoVR]

For me doesn't work on network files.

If I open a file on the network from one PC and then start AutoIt from my PC .. when he checks if the file is open returns False! 

File opened on the network DiskstationVirtualCommercialeMarketplaceEsportazioniperAUTOITXLS-MetaclassiV3.xls. 

If opened from another PC:

Local Const $hFileOpen = _WinAPI_CreateFile($sFilePath, $CREATE_ALWAYS, $FILE_SHARE_WRITE) returns 0

Then $fReturn = False

If not opened from another PC

Local Const $hFileOpen = _WinAPI_CreateFile($sFilePath, $CREATE_ALWAYS, $FILE_SHARE_WRITE) returns <HWnd>0x000001FC 

then tries to close the handle and returns "False"

Do you have any suggestion?

[jdelaney]

I know running 'net file' on the server housing the file will return if the file is opened by an outside computer.

It's the same as viewing 'Open file shares' through Server Management.

I'm not certain of anyone creating a wrapping function for that.  Best I could suggest is to use psexec to execute it on the server.  But that requires you have the rights to do so.