' FB 1.05.0 Win64

Type ConfigData
  favouriteFruit As String
  needsPeeling As Boolean
  seedsRemoved As Boolean
  numberOfBananas As UInteger
  numberOfStrawberries As UInteger
End Type

Sub updateConfigData(fileName As String, cData As ConfigData)
  Dim fileNum As Integer = FreeFile
  Open fileName For Input As #fileNum
  If err > 0 Then
    Print "File could not be opened"
    Sleep
    End
  End If
  Dim tempFileName As String = "temp_" + fileName
  Dim fileNum2 As Integer = FreeFile
  Open tempFileName For Output As #fileNum2
  Dim As Boolean hadFruit, hadPeeling, hadSeeds, hadBananas, hadStrawberries '' all false by default
  Dim As String ln
  While Not Eof(fileNum)
    Line Input #fileNum, ln
    If ln = "" OrElse Left(ln, 1) = "#" Then
      Print #fileNum2, ln
      Continue While
    End If
    ln = Trim(LTrim(ln, ";"), Any !" \t")
    If ln = "" Then Continue While
    If UCase(Left(ln, 14)) = "FAVOURITEFRUIT" Then
      If hadFruit Then Continue While
      hadFruit = True
      Print #fileNum2, "FAVOURITEFRUIT " + cData.favouriteFruit
    ElseIf UCase(Left(ln, 12)) = "NEEDSPEELING" Then
      If hadPeeling Then Continue While
      hadPeeling = True
      If cData.needsPeeling Then
        Print #fileNum2, "NEEDSPEELING"
      Else
        Print #fileNum2, "; NEEDSPEELING"
      End If
    ElseIf UCase(Left(ln, 12)) = "SEEDSREMOVED" Then
      If hadSeeds Then Continue While
      hadSeeds = True
      If cData.seedsRemoved Then
        Print #fileNum2, "SEEDSREMOVED"
      Else
        Print #fileNum2, "; SEEDSREMOVED"
      End If
    ElseIf UCase(Left(ln, 15)) = "NUMBEROFBANANAS" Then
      If hadBananas Then Continue While
      hadBananas = True
      Print #fileNum2, "NUMBEROFBANANAS " + Str(cData.numberOfBananas)
    ElseIf UCase(Left(ln, 20)) = "NUMBEROFSTRAWBERRIES" Then
      If hadStrawberries Then Continue While
      hadStrawberries = True
      Print #fileNum2, "NUMBEROFSTRAWBERRIES " + Str(cData.numberOfStrawBerries)
    End If
  Wend

  If Not hadFruit Then
     Print #fileNum2, "FAVOURITEFRUIT " + cData.favouriteFruit
  End If
  If Not hadPeeling Then
    If cData.needsPeeling Then
      Print #fileNum2, "NEEDSPEELING"
    Else
      Print #fileNum2, "; NEEDSPEELING"
    End If
  End If
  If Not hadSeeds Then
    If cData.seedsRemoved Then
      Print #fileNum2, "SEEDSREMOVED"
    Else
      Print #fileNum2, "; SEEDSREMOVED"
    End If
  End If
  If Not hadBananas Then
    Print #fileNum2, "NUMBEROFBANANAS " + Str(cData.numberOfBananas)
  End If
  If Not hadStrawberries Then
    Print #fileNum2, "NUMBEROFSTRAWBERRIES " + Str(cData.numberOfStrawBerries)
  End If

  Close #fileNum : Close #fileNum2
  Kill(fileName)
  Name (tempFileName fileName)
End Sub

Dim fileName As String = "config2.txt"
Dim cData As ConfigData
With cData
  .favouriteFruit = "banana"
  .needsPeeling = False
  .seedsRemoved = True
  .numberOfBananas = 1024
  .numberOfStrawberries = 62000
End With

updateConfigData fileName, cData
Print
Print "Press any key to quit"
Sleep