[RESOLVED] Dir() reentrancy?

I have a directory with about 30,000 files with a type, say, .xxx. Almost every one of these files has a file of type .yyy, type .zzz or type .yymmdd (where yymmdd is a date) associated with it.

I have to find each .xxx file that has an associated file and rename the .xxx file. Finding the file is easy, in a loop using Dir(). However, if I use Dir() within the loop to find the associated file, the outer loop's Dir() no longer works - it's not a reentrant function.

I can use fso.FindFile inside the loop, but FindFile doesn't accept wildcards, and the dates run from Jan. 1, 2005 to the current day, so the inner loop would execute over 14 million times, and I'm not sure I'll live long enough to see the results. Can anyone think of a more elegant way of doing this? Is there an API I can use that accepts wildcards and that isn't being used by the Dir() function? Am I overlooking a simple solution?

TIA

There are a number of ways to approach this problem.
As you have so many files to check, it may make sense to just
enumerate the files in the directory once and then sort out what to do with
them as a secondary process.

Here's one example:

VB Code:

'
' ClassModule: FileInfo
'
Option Explicit
 
Public Name As String
Public FullPath As String
Public HasXXX As Boolean
Public HasYYY As Boolean
Public HasZZZ As Boolean
Public HasYMD As Boolean

VB Code:

Option Explicit
 
Private Sub Command1_Click()
  Dim strDir As String
  Dim files As New Collection
  Dim strExt As String
  Dim strPath As String
  Dim file As FileInfo
 
  ' Set the path to be enumerated for files
  strPath = "C:\SomeFolder\"
  ' Get the first file in the folder
  strDir = Dir(strPath & "*.*", vbNormal)
  ' Loop this code until there are no more files
  Do While Len(strDir) > 0
    ' Get the files extension
    strExt = JustExt(strDir)
    ' If it's an XXX, YYY or ZZZ extension or the extension
    ' is a valid date in the format YYMMDD, then process it
    If InStr(";xxx;yyy;zzz;", ";" & LCase(strExt) & ";") Or _
       IsDate(Format(strExt, "@@-@@-@@")) Then
       ' Add the file to our collection of files
       Call AddFile(files, strPath & strDir)
    End If
    ' Get the next file in the folder
    strDir = Dir
  Loop
  
  ' List the files that have an XXX extension and a file
  ' association with a YYMMDD format extension
  List1.Clear
  For Each file In files
    If file.HasXXX And file.HasYMD Then
      Call List1.AddItem(file.FullPath & file.Name & ".xxx")
    End If
  Next
End Sub
 
Private Sub AddFile(ByRef files As Collection, ByVal strFile As String)
  Dim file As New FileInfo
  Dim strExt As String
  Dim flgExists As Boolean
  
  ' Trap an error caused if the file isn't
  ' already in the collection
  On Local Error GoTo FileNotFound
  ' Attempt to get the file from the collection
  Set file = files(JustStem(strFile))
  ' If we get this far, the file exists
  flgExists = True
  
FileNotFound:
  ' Reset the error handler
  On Local Error GoTo 0
  
  ' Get the File's extension
  strExt = JustExt(strFile)
    
  ' Assign the Name of the file (without extension)
  file.Name = JustStem(strFile)
  ' Assign the Path of the file
  file.FullPath = JustPath(strFile)
  
  ' If the file has an XXX extension, set the XXX flag
  If LCase(strExt) = "xxx" Then
    file.HasXXX = True
    
  ' If the file has an YYY extension, set the YYY flag
  ElseIf LCase(strExt) = "yyy" Then
    file.HasYYY = True
    
  ' If the file has an ZZZ extension, set the ZZZ flag
  ElseIf LCase(strExt) = "zzz" Then
    file.HasZZZ = True
    
  ' If the file has an YYMMDD extension, set the YMD flag
  ElseIf IsDate(Format(strExt, "@@-@@-@@")) Then
    file.HasYMD = True
    
  End If
  
  ' If the file is in the collection, remove it
  If flgExists Then
    Call files.Remove(file.Name)
  End If
  ' Add the file to the collection
  files.Add file, file.Name
End Sub
 
' Returns just the Path of the supplied filename
Private Function JustPath(ByVal fileName As String) As String
  If InStr(fileName, "\") > 0 Then
    fileName = Left(fileName, InStrRev(fileName, "\"))
  Else
    fileName = ""
  End If
  JustPath = fileName
End Function
 
' Returns just the File of the supplied file/path name
Private Function JustFile(ByVal fileName As String) As String
  If InStr(fileName, "\") > 0 Then
    fileName = Mid(fileName, InStrRev(fileName, "\") + 1)
  End If
  JustFile = fileName
End Function
 
' Returns just the stem portion of the filename
' (the part without the extension)
Private Function JustStem(ByVal fileName As String) As String
  fileName = JustFile(fileName)
  If InStr(fileName, ".") > 0 Then
    fileName = Left(fileName, InStrRev(fileName, ".") - 1)
  End If
  JustStem = fileName
End Function
 
' Returns just the file's extension
Private Function JustExt(ByVal fileName As String) As String
  Dim strExt As String
  If InStr(fileName, ".") > 0 Then
    strExt = Mid(fileName, InStrRev(fileName, ".") + 1)
  End If
  JustExt = strExt
End Function

Regards,

- Aaron.

I never even thought of atttacking it that way, Aaron. Thank you.