vbscript: convert unicode string to array of bytes

I have unicode string passed to vbscript procedure (not visual basic 6, but vbscript). I want to iterate unicode string char by char, get code for every symbol, truncate code to byte range [0..255] and create array of bytes.

This way new array of bytes should be twice smaller in memory compared to original unicode string. I am going save this array to file via ADODB.Stream object further

How can I co开发者_StackOverflow社区nvert unicode string to bytes array with symbol code truncated to byte range?

Thank you in advance!

Firstly, translating unicode to ascii will only work if your string only contains ascii characters. Since unicode contains ascii, it is just a matter of removing every second character.

Look up unicode on the internet for details.

EDIT: In unicode, every ascii character is proceeded with a NULL (0) byte. Remove this byte to convert the string to ASCII.

It seems there is no way to create array of bytes in vbs (though it's very straightforward in visual basic) -- all arrays are arrays of variants.

The task was to send binary stream from server to vbs script via string type. I have found the solution by creating Xml Document on the server with CDATA section that contains base64 coded array of bytes as string data.

Client (vbs) do the following:

set xmlDoc = CreateObject("Microsoft.XmlDom")
xmlDoc.loadXML(dataFromServer)
base64str = xmlDoc.DocumentElement.Text  ' it's base64 coded binary stream
arrayOfBytes = decodeBase64(base64str)

Function decodeBase64(base64)  
  set dm = CreateObject("Microsoft.XMLDOM")
  set el = dm.createElement("tmp")
  el.DataType = "bin.base64"
  el.Text = base64
  decodeBase64 = el.NodeTypedValue
  set dm = Nothing
End Function

This function creates an array of bytes:

' http://www.motobit.com/tips/detpg_binarytostring/
Function MultiByteToBinary(MultiByte)
  '� 2000 Antonin Foller, http://www.motobit.com
  ' MultiByteToBinary converts multibyte string To real binary data (VT_UI1 | VT_ARRAY)
  ' Using recordset
  Dim RS, LMultiByte, Binary
  Const adLongVarBinary = 205
  Set RS = CreateObject("ADODB.Recordset")
  LMultiByte = LenB(MultiByte)
  If LMultiByte>0 Then
    RS.Fields.Append "mBinary", adLongVarBinary, LMultiByte
    RS.Open
    RS.AddNew
      RS("mBinary").AppendChunk MultiByte & ChrB(0)
    RS.Update
    Binary = RS("mBinary").GetChunk(LMultiByte)
  End If
  MultiByteToBinary = Binary
End Function

This function creates a multi-byte string.

' http://www.motobit.com/help/regedit/pa26.htm
'Converts unicode string to a multibyte string
Function StringToMB(S)
  Dim I, B
  For I = 1 To Len(S)
    B = B & ChrB(Asc(Mid(S, I, 1)))
  Next
  StringToMB = B
End Function