B4J Question DiskUtils: get free space of Linux path (drive)

'bytes
Private Sub Get_FreeSpace(Fold As String) As Long
    '(ArrayList) [C:\, D:\, E:\, P:\, R:\]
    '(MyMap) {C:\=126100873216, D:\=125829115904, E:\=104857595904, P:\=258932207616, R:\=104857595904}
    '(MyMap) {C:\=30034104320, D:\=34107752448, E:\=20868218880, P:\=16199786496, R:\=20868218880}
    '(MyMap) {C:\=30034104320, D:\=34107752448, E:\=20868218880, P:\=16199786496, R:\=20868218880}
    '(MyMap) {C:\=96066768896, D:\=91721363456, E:\=83989377024, P:\=242732421120, R:\=83989377024}
  
    If DetectOS = "windows" Then
        Dim drive As String = Fold.SubString2(0, 3).ToUpperCase
    Else If DetectOS = "linux" Then
        Dim drive As String = "/"
    End If
  
  
    Private TotalDrives As List
    TotalDrives.Initialize
    TotalDrives=DiskUtils.GetDrives
    'Log (TotalDrives)
  
    Private TotalDriveCapacity As Map
    TotalDriveCapacity.Initialize
    TotalDriveCapacity=DiskUtils.GetDrivesCapacity
    'Log (TotalDriveCapacity)
  
    Private TotalUsableSpace As Map
    TotalUsableSpace.Initialize
    TotalUsableSpace=DiskUtils.GetUsableSpace
    'Log (TotalUsableSpace)
  
    Private TotalFreeSpace As Map
    TotalFreeSpace.Initialize
    TotalFreeSpace=DiskUtils.GetFreeSpace
    'Log(TotalFreeSpace)
  
    Private Writable As Map
    Writable.Initialize
    Writable=DiskUtils.Writable
  
    Private UsedSpace As Map
    UsedSpace.Initialize
    UsedSpace=DiskUtils.GetUsedSpace
    'Log(UsedSpace)
  

    Dim u As Long = TotalUsableSpace.Get(drive)
  
    Return u
  
    Dim t As Long = TotalDriveCapacity.Get(drive)
    Dim res As Int = (100-((t - u)/t) * 100)
    'Log (res)
    Return res
End Sub

Sub DetectOS As String
    Dim os As String = GetSystemProperty("os.name", "").ToLowerCase
    If os.Contains("win") Then
        Return "windows"
    Else If os.Contains("mac") Then
        Return "mac"
    Else
        Return "linux"
    End If
End Sub