.lib "kernel32.dll"

api_FindFirstChangeNotification% (lpPathName$, bWatchSubtree%, dwNotifyFilter%) : "FindFirstChangeNotificationA"

The FindFirstChangeNotification function creates a change notification handle and sets up initial change notification filter conditions. A wait on a notification handle succeeds when a change matching the filter conditions occurs in the specified directory or subtree.

HANDLE FindFirstChangeNotification(

    LPCTSTR lpPathName,   // pointer to name of directory to watch 
    BOOL bWatchSubtree,   // flag for monitoring directory or directory tree 
    DWORD dwNotifyFilter    // filter conditions to watch for
   );   
 

Parameters

lpPathName

Points to a null-terminated string that specifies the path of the directory to watch.

bWatchSubtree

Specifies whether the function will monitor the directory or the directory tree. If this parameter is TRUE, the function monitors the directory tree rooted at the specified directory; if it is FALSE, it monitors only the specified directory.

dwNotifyFilter

Specifies the filter conditions that satisfy a change notification wait. This parameter can be one or more of the following values:

Value   Meaning
FILE_NOTIFY_CHANGE_FILE_NAME   
Any filename change in the watched directory or subtree causes a change notification wait operation to return. Changes include renaming, creating, or deleting a filename.
FILE_NOTIFY_CHANGE_DIR_NAME   
Any directory-name change in the watched directory or subtree causes a change notification wait operation to return. Changes include creating or deleting a directory.
FILE_NOTIFY_CHANGE_ATTRIBUTES   
Any attribute change in the watched directory or subtree causes a change notification wait operation to return.
FILE_NOTIFY_CHANGE_SIZE   
Any file-size change in the watched directory or subtree causes a change notification wait operation to return. The operating system detects a change in file size only when the file is written to the disk. For operating systems that use extensive caching, detection occurs only when the cache is sufficiently flushed.
FILE_NOTIFY_CHANGE_LAST_WRITE   
Any change to the last write-time of files in the watched directory or subtree causes a change notification wait operation to return. The operating system detects a change to the last write-time only when the file is written to the disk. For operating systems that use extensive caching, detection occurs only when the cache is sufficiently flushed.
FILE_NOTIFY_CHANGE_SECURITY   
Any security-descriptor change in the watched directory or subtree causes a change notification wait operation to return.
 

Return Values

If the function succeeds, the return value is a handle to a find change notification object.
If the function fails, the return value is INVALID_HANDLE_VALUE. To get extended error information, call GetLastError.

Remarks

The wait functions can monitor the specified directory or subtree by using the handle returned by the FindFirstChangeNotification function. A wait is satisfied when one of the filter conditions occurs in the monitored directory or subtree.
After the wait has been satisfied, the application can respond to this condition and continue monitoring the directory by calling the FindNextChangeNotification function and the appropriate wait function. When the handle is no longer needed, it can be closed by using the FindCloseChangeNotification function.

See Also

FindCloseChangeNotification, FindNextChangeNotification

.lib "Kernel32.dll"
CreateFile%(lpFileName$,dwDesiredAccess%,dwShareMode%,lpSecurityAttributes%,dwCreationDispostion%,dwFlagsAndAttributes%,hTemplateFile%):"CreateFileA"
CloseHandle%(hFile%):"CloseHandle"
FindFirstFile%(lpFileName$,lpFindFileData*):"FindFirstFileA"
FindClose%(hFindFile%):"FindClose"

Const GENERIC_READ% = $80000000
Const OPEN_EXISTING% = 3
Const FILE_ATTRIBUTE_NORMAL% = $80

Function IsFileInUse(sFile$)
   WIN32_FIND_DATA = CreateBank(512)

   If FileExists(sFile , WIN32_FIND_DATA) Then
      hFile = CreateFile(sFile,GENERIC_READ,0,0,OPEN_EXISTING,FILE_ATTRIBUTE_NORMAL,0)
      CloseHandle hFile

      If hFile = -1
         Print "File is in use"      
      Else
         Print "File is available"      
      EndIf
   Else
      Print "File does not exist!"
   EndIf
   FreeBank WIN32_FIND_DATA
End Function

Function FileExists(sSource$ , bank%)
   hFile = FindFirstFile(sSource, bank)
   FindClose(hFile)
      
   Return hFile <> -1
End Function

;Datei erstellen
testFile=WriteFile("c:\test.txt")

;1. Test - sollte "File is in use" zurückgeben
IsFileInUse("c:\test.txt")

;Datei schliessen
CloseFile testFile

;2. Test - sollte "File is available" zurückgeben
IsFileInUse("c:\test.txt")

;Datei löschen
DeleteFile ("c:\test.txt")

;3. Test - sollte "File does not exist!" zurückgeben
IsFileInUse("c:\test.txt")