Excel VBA Macro for Filename processing

FilenameProcessing.bas

Option Explicit

Function dirname(ByVal inVal As String, Optional directorySeparater As String = "/") As String
    Dim basenameStr As String
    basenameStr = basename(inVal, directorySeparater)
    If basenameStr <> inVal Then
        dirname = Left(inVal, Len(inVal) - Len(basenameStr) - 1)
    Else
        dirname = "."
    End If
End Function

Function basename(ByVal inVal As String, Optional directorySeparater As String = "/") As String
    Dim index As Integer
    
    index = InStrRev(inVal, directorySeparater)
    If index > 0 Then
        basename = Mid(inVal, index + 1)
    Else
        basename = Mid(inVal, index + 1)
    End If
End Function