Module QueryDuplicateFileNames

    Public Sub Main()

        Dim path As String = "C:\Program Files\Microsoft Visual Studio 9.0\Common7"
        'QueryDuplicates1(path)
        ' Uncomment to run this query instead
        QueryDuplicates2(path)

    End Sub
    Sub QueryDuplicates1(ByVal root As String)

        Dim duplicates = From aFile In GetFiles(root) _
                                 Order By aFile.Name _
                                 Group aFile By aFile.Name Into newGroup = Group _
                                 Where newGroup.Count() >= 2 _
                                 Select newGroup

        ' Page the display so that the results can be read.
        Dim trimLength = root.Length
        PageOutput(duplicates, trimLength)

    End Sub
    Sub QueryDuplicates2(ByVal root As String)

        ' This time a composite key is used. This sub finds all files
        ' that have been copied into multiple subfolders.
        Dim duplicates = From aFile In GetFiles(root) _
                                 Order By aFile.Name _
                                 Group aFile By aFile.Name, aFile.CreationTime, aFile.Length Into newGroup = Group _
                                 Where newGroup.Count() >= 2 _
                                 Select newGroup

        ' Page the display so that the results can be read.
        Dim trimLength = root.Length
        PageOutput(duplicates, trimLength)

    End Sub
    ' Pages console diplay for large query results. No more than one group per page.
    ' This sub specifically works with group queries of FileInfo objects
    ' but can be modified for any type.
    Sub PageOutput(ByVal groupQuery, ByVal charsToSkip)

        ' "3" = 1 line for extension key + 1 for "Press any key" + 1 for input cursor.
        Dim numLines As Integer = Console.WindowHeight - 3
        ' Flag to indicate whether there are more results to diplay
        Dim goAgain As Boolean = True

        For Each fg As IEnumerable(Of System.IO.FileInfo) In groupQuery
            ' Start a new extension at the top of a page.
            Dim currentLine As Integer = 0

            Do While (currentLine < fg.Count())
                Console.Clear()

                ' Get the next page of results
                ' No more than one filename per page
                Dim resultPage = From file In fg _
                                Skip currentLine Take numLines

                ' Execute the query. Trim the paths in the output.
                For Each line In resultPage
                    Console.WriteLine(vbTab & line.FullName.Substring(charsToSkip))
                Next

                ' Advance the current position
                currentLine = numLines + currentLine

                ' Give the user a chance to break out of the loop
                Console.WriteLine("Press any key for next page or the 'End' key to exit.")
                Dim key As ConsoleKey = Console.ReadKey().Key
                If key = ConsoleKey.End Then
                    goAgain = False
                    Exit For
                End If
            Loop
        Next
    End Sub

    ' Function to retrieve a list of files. Note that this is a copy
    ' of the file information.
    Function GetFiles(ByVal root As String) As System.Collections.Generic.IEnumerable(Of System.IO.FileInfo)
        Return From file In My.Computer.FileSystem.GetFiles _
                  (root, FileIO.SearchOption.SearchAllSubDirectories, "*.*") _
               Select New System.IO.FileInfo(file)
    End Function
End Module