Procedure.s WalkRecursive(dir,path.s,Pattern.s="\.txt$")
  Static RegularExpression
  If Not RegularExpression
    RegularExpression=CreateRegularExpression(#PB_Any,Pattern)
  EndIf

  While NextDirectoryEntry(dir)
    If DirectoryEntryType(dir)=#PB_DirectoryEntry_Directory
      If DirectoryEntryName(dir)<>"." And DirectoryEntryName(dir)<>".."
        If ExamineDirectory(dir+1,path+DirectoryEntryName(dir),"")
          WalkRecursive(dir+1,path+DirectoryEntryName(dir)+"\",Pattern)
          FinishDirectory(dir+1)
        Else
          Debug "Error in "+path+DirectoryEntryName(dir)
        EndIf
      EndIf
    Else ; e.g. #PB_DirectoryEntry_File
      If MatchRegularExpression(RegularExpression,DirectoryEntryName(dir))
        Debug DirectoryEntryName(dir)
      EndIf
    EndIf
  Wend
EndProcedure