how can I write UTF-8 encoded strings to a textfile from vba, like
Dim fnum As Integer
fnum = FreeFile
Open "myfile.txt" For Output As fnum
Print #fnum, "special characters: äöüß" 'latin-1 or something by default
Close fnum
Is there some setting on Application level?
I found the answer on the web:
Dim fsT As Object
Set fsT = CreateObject("ADODB.Stream")
fsT.Type = 2 'Specify stream type - we want To save text/string data.
fsT.Charset = "utf-8" 'Specify charset For the source text data.
fsT.Open 'Open the stream And write binary data To the object
fsT.WriteText "special characters: äöüß"
fsT.SaveToFile sFileName, 2 'Save binary data To disk
Certainly not as I expected...
You can use CreateTextFile or OpenTextFile method, both have an attribute "unicode" usefull for encoding settings.
object.CreateTextFile(filename[, overwrite[, unicode]])
object.OpenTextFile(filename[, iomode[, create[, format]]])
Example: Overwrite:
CreateTextFile:
fileName = "filename"
Set fso = CreateObject("Scripting.FileSystemObject")
Set out = fso.CreateTextFile(fileName, True, True)
out.WriteLine ("Hello world!")
...
out.close
Example: Append:
OpenTextFile Set fso = CreateObject("Scripting.FileSystemObject")
Set out = fso.OpenTextFile("filename", ForAppending, True, 1)
out.Write "Hello world!"
...
out.Close
See more on MSDN docs
This writes a Byte Order Mark at the start of the file, which is unnecessary in a UTF-8 file and some applications (in my case, SAP) don't like it. Solution here: Can I export excel data with UTF-8 without BOM?
Here is another way to do this - using the API function WideCharToMultiByte:
Option Explicit
Private Declare Function WideCharToMultiByte Lib "kernel32.dll" ( _
ByVal CodePage As Long, _
ByVal dwFlags As Long, _
ByVal lpWideCharStr As Long, _
ByVal cchWideChar As Long, _
ByVal lpMultiByteStr As Long, _
ByVal cbMultiByte As Long, _
ByVal lpDefaultChar As Long, _
ByVal lpUsedDefaultChar As Long) As Long
Private Sub getUtf8(ByRef s As String, ByRef b() As Byte)
Const CP_UTF8 As Long = 65001
Dim len_s As Long
Dim ptr_s As Long
Dim size As Long
Erase b
len_s = Len(s)
If len_s = 0 Then _
Err.Raise 30030, , "Len(WideChars) = 0"
ptr_s = StrPtr(s)
size = WideCharToMultiByte(CP_UTF8, 0, ptr_s, len_s, 0, 0, 0, 0)
If size = 0 Then _
Err.Raise 30030, , "WideCharToMultiByte() = 0"
ReDim b(0 To size - 1)
If WideCharToMultiByte(CP_UTF8, 0, ptr_s, len_s, VarPtr(b(0)), size, 0, 0) = 0 Then _
Err.Raise 30030, , "WideCharToMultiByte(" & Format$(size) & ") = 0"
End Sub
Public Sub writeUtf()
Dim file As Integer
Dim s As String
Dim b() As Byte
s = "äöüßµ@€|~{}[]²³\ .." & _
" OMEGA" & ChrW$(937) & ", SIGMA" & ChrW$(931) & _
", alpha" & ChrW$(945) & ", beta" & ChrW$(946) & ", pi" & ChrW$(960) & vbCrLf
file = FreeFile
Open "C:\Temp\TestUtf8.txt" For Binary Access Write Lock Read Write As #file
getUtf8 s, b
Put #file, , b
Close #file
End Sub
I looked into the answer from Máťa whose name hints at encoding qualifications and experience. The VBA docs say CreateTextFile(filename, [overwrite [, unicode]]) creates a file "as a Unicode or ASCII file. The value is True if the file is created as a Unicode file; False if it's created as an ASCII file. If omitted, an ASCII file is assumed." It's fine that a file stores unicode characters, but in what encoding? Unencoded unicode can't be represented in a file.
The VBA doc page for OpenTextFile(filename[, iomode[, create[, format]]]) offers a third option for the format:
Máťa passes -1 for this argument.
Judging from VB.NET documentation (not VBA but I think reflects realities about how underlying Windows OS represents unicode strings and echoes up into MS Office, I don't know) the system default is an encoding using 1 byte/unicode character using an ANSI code page for the locale. UnicodeEncoding is UTF-16. The docs also describe UTF-8 is also a "Unicode encoding," which makes sense to me. But I don't yet know how to specify UTF-8 for VBA output nor be confident that the data I write to disk with the OpenTextFile(,,,1) is UTF-16 encoded. Tamalek's post is helpful.
