Detecting file type in vba for word

Question

I have directories full of files on a Mac.  Most of these files are Doc files, some Txt files and some other types. Unfortunately the files don't have file extensions (not hidden but actually no file extensions).  On a PC in a macro I need to open
these  doc files (from the Mac) and do some manipulations on the files and then save them.  I have a macro which works as long as all the files are Doc files so if I can detect the file type in my macro I can skip the non-Doc files and process only
the Doc files.
Is there a way in a vba for word macro to detect a file type other than by the file extension?  Or if that can't be done can I put error trapping on my Open statement that will catch an attempt to Open a non-Doc type file?
Thanks
Harry Spier

Answer 1

If your code is running on Windows and you are in a position to install software on it, you
may be able to get reasonably reliable detection using dsofile.dll, which you can get here:
I really do not know whether it will work with files stored or create on Mac (and in any case, if these are old Mac .doc files, you may find that Windows Word cannot open them anyway.
You need to
 - register the dll via regsvr32
 - in VBE, use Tools->References... to make a reference to"DSO OLE Document Properties Reader 2.1"
 - use code such as the sample below. 
Option Explicit
Function IsWordDoc(FullName As String) As Boolean
' FullName is the full path name of the file you want to check
Dim objDocumentProperties As DSOFile.OleDocumentProperties
IsWordDoc = False
Set objDocumentProperties = New DSOFile.OleDocumentProperties
' or you can add dsoOptionOnlyOpenOLEFiles to the options and
' use error trapping to detect -2147217148
objDocumentProperties.Open sFileName:=FullName, ReadOnly:=True, Options:=dsoOptionDontAutoCreate
If objDocumentProperties.IsOleFile Then
If objDocumentProperties.OleDocumentFormat = "MSWordDoc" Then
IsWordDoc = True
End If
End If
objDocumentProperties.Close savebeforeclose:=False
Set objDocumentProperties = Nothing
End Function
Sub testIsWordDoc()
Debug.Print IsWordDoc("c:\a\test.doc")
Debug.Print IsWordDoc("c:\a\test.xls")
End Sub
You may also find that the value of the property I am checking varies and that you need to look at other things, such as 
objDocumentProperties.SummaryProperties.ApplicationName
but that value definitely varies according to the version of Word used to create the .doc, so you would need to discover what values it can have in a valid .doc.
Peter Jamieson