Write text file in appending (utf-8 encoded) in VB6 - utf-8

Question

I have to write a textfile in VB6. I need to do it in appending and utf-8 encoded.
I tried two solutions, one with "TextStream" and another one with "ADODB.Stream".
The first one:
Set fsoFile = fso.OpenTextFile(FileIn(fi), ForAppending, True)
fsoFile.WriteLine "<tag>kkkjòòkkkkjlòlk</tag>"
fsoFile.Close
Works good in appending but how can I write it utf-8 encoded?
The second one:
Dim ST As ADODB.Stream
Set ST = New ADODB.Stream
ST.Mode = adModeReadWrite
ST.Type = adTypeText
ST.Charset = "UTF-8"
ST.Open
ST.LoadFromFile FileIn(fi)
ST.Position = ST.Size
ST.WriteText "<tag>kkkjòòkkkkjlòlk</tag>"
ST.SaveToFile FileIn(fi)
ST.Close
Write correctly in utf-8 but I can't write the file in appending but only with "adSaveCreateOverWrite".
How can I do that? Is there another way?
Thank you very much.

Answer 1

You could combine binary I/O with an API call to perform the conversion to UTF-8:
Option Explicit
Private Const CP_UTF8 As Long = 65001
Private Declare Function WideCharToMultiByte Lib "kernel32" ( _
ByVal CodePage As Long, _
ByVal dwFlags As Long, _
ByVal lpWideCharStr As Long, _
ByVal cchWideChar As Long, _
ByVal lpMultiByteStr As Long, _
ByVal cchMultiByte As Long, _
ByVal lpDefaultChar As Long, _
ByVal lpUsedDefaultChar As Long) As Long
Private Function OpenAppendUTF8(ByVal FileName As String) As Integer
OpenAppendUTF8 = FreeFile(0)
Open FileName For Binary Access Write As #OpenAppendUTF8
Seek #OpenAppendUTF8, LOF(OpenAppendUTF8) + 1
End Function
Private Sub WriteUTF8( _
ByVal FNum As Integer, _
ByVal Text As String, _
Optional ByVal NL As Boolean)
Dim lngResult As Long
Dim UTF8() As Byte
If NL Then Text = Text & vbNewLine
lngResult = WideCharToMultiByte(CP_UTF8, 0, StrPtr(Text), Len(Text), _
0, 0, 0, 0)
If lngResult > 0 Then
ReDim UTF8(lngResult - 1)
WideCharToMultiByte CP_UTF8, 0, StrPtr(Text), Len(Text), _
VarPtr(UTF8(0)), lngResult, 0, 0
Put #FNum, , UTF8
End If
End Sub
Private Sub Main()
Dim F As Integer
F = OpenAppendUTF8("test.txt")
WriteUTF8 F, "Hello"
WriteUTF8 F, ChrW$(&H2026&)
WriteUTF8 F, "World", True
Close #F
MsgBox "Done"
End Sub

Answer 2

I prefer to save it ANSI as it does by default. Open it with a notepad and overwrite it selecting UTF8 encoding. I found it's the fastest way by far.
And I use some other code to append, for example for a database convertion:
Dim fs As Object, a
Set fs = CreateObject("Scripting.FileSystemObject")
Set a = fs.CreateTextFile(filename, True) 'example (myfile.xml, True)
a.writeline var1
a.writeline var2
a.Close

Answer 3

Actually no need for API call.
Option Explicit
Sub testAppend()
Dim fileName
fileName = "C:\Test\test.txt"
Dim f As Integer
f = FreeFile(0)
Open fileName For Binary Access Write As #f
Seek #f, LOF(f) + 1
Dim t
t = "<tag>" & ChrW(107) & ChrW(107) & ChrW(107) & ChrW(106) & ChrW(242) & ChrW(242) & ChrW(107) & ChrW(107) & ChrW(107) & ChrW(107) & ChrW(106) & ChrW(108) & ChrW(242) & ChrW(108) & ChrW(107) & "</tag>"
Put #f, , textToBinary(t, "utf-8")
Close #f
End Sub
Function textToBinary(text, charset) As Byte()
With CreateObject("ADODB.Stream")
.Open
.Type = 2 ' adTypeText
.charset = charset
.WriteText text
.Position = 0
.Type = 1 ' adTypeBinary
textToBinary = .Read
.Close
End With
End Function```