Write text files without Byte Order Mark (BOM)?

byte-order-mark, encoding, file-handling, vb.net

Solution

In order to omit the byte order mark (BOM), your stream must use an instance of `UTF8Encoding` other than `System.Text.Encoding.UTF8` (which is configured to generate a BOM). There are two easy ways to do this:

1. Explicitly specifying a suitable encoding:

Call the `UTF8Encoding` constructor with `False` for the `encoderShouldEmitUTF8Identifier` parameter.

Pass the `UTF8Encoding` instance to the stream constructor.

' VB.NET:
Dim utf8WithoutBom As New System.Text.UTF8Encoding(False)
Using sink As New StreamWriter("Foobar.txt", False, utf8WithoutBom)
    sink.WriteLine("...")
End Using

// C#:
var utf8WithoutBom = new System.Text.UTF8Encoding(false);
using (var sink = new StreamWriter("Foobar.txt", false, utf8WithoutBom))
{
    sink.WriteLine("...");
}

2. Using the default encoding:

If you do not supply an `Encoding` to `StreamWriter`'s constructor at all, `StreamWriter` will by default use an UTF8 encoding without BOM, so the following should work just as well:

' VB.NET:
Using sink As New StreamWriter("Foobar.txt")
    sink.WriteLine("...")
End Using

// C#:
using (var sink = new StreamWriter("Foobar.txt"))
{
    sink.WriteLine("...");
}

Finally, note that omitting the BOM is only permissible for UTF-8, not for UTF-16.

Problem

I am trying to create a text file using VB.Net with UTF8 encoding, without BOM. Can anybody help me, how to do this? I can write file with UTF8 encoding but, how to remove Byte Order Mark from it? edit1: I have tried code like this; ``` Dim utf8 As New UTF8Encoding() Dim utf8EmitBOM As New UTF8Encoding(True) Dim strW As New StreamWriter("c:\temp\bom\1.html", True, utf8EmitBOM) strW.Write(utf8EmitBOM.GetPreamble()) strW.WriteLine("hi there") strW.Close() Dim strw2 As New StreamWriter("c:\temp\bom\2.html", True, utf8) strw2.Write(utf8.GetPreamble()) strw2.WriteLine("hi there") strw2.Close() ``` 1.html get created with UTF8 encoding only and 2.html get created with ANSI encoding format. Simplified approach - http://whatilearnttuday.blogspot.com/2011/10/write-text-files-without-byte-order.html

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