VB Forum / Win API / September 2003

Sure, but it won't be any more effective or simpler to implement than
just attempting to Open the file for exclusive (Lock Read Write)
access and trapping the error (55, IIRC) if it's already open.

Ex:

Public Function IsOpen(sFileName As String) As Boolean
   Dim nFile As Long
   
   On Error GoTo EH_Proc
   nFile = FreeFile
   'Attempt to get exclusive access.
   '(Using input mode won't create new file if it doesn't exist.)
   Open sFileName For Input Lock Read Write As nFile
   Close nFile
   Exit Function '==============>>>
EH_Proc:
    If Err.Number = 55 Then
        IsOpen = True
    End If
End Function

-Tom
MVP - Visual Basic
(please post replies to the newsgroup)

Public Function IsFileAvailable(ByVal aFilename As String, Optional ByVal
ForWrite As Boolean = True, Optional ByVal ExclAccess As Boolean = True) As
Boolean
 Dim f As Integer
 On Error Resume Next
 f = FreeFile
 IsFileAvailable = False
 If aFilename = "" Then Exit Function
 Err.Clear
 If ExclAccess Then
   If ForWrite Then
     Open aFilename For Binary Access Read Write Lock Read Write As #f
   Else
     Open aFilename For Binary Access Read Lock Read Write As #f
   End If
 Else
   If ForWrite Then
     Open aFilename For Binary Access Read Write Shared As #f
   Else
     Open aFilename For Binary Access Read Shared As #f
   End If
 End If
 Close #f
 If Err.Number = 0 Then
   IsFileAvailable = True
 End If
 Err.Clear
End Function