Ruby

Convert a File's Character Encoding from UTF-8 to UFT-8-BOM

See more HTML-to-XML/Text Examples

To add a utf-8 BOM to a file is just a matter of prepending these 3 bytes to the file: 0xEF 0xBB 0xBF.

This may be difficult in some programming languages, or it may be trivial in either. Therefore, the Chilkat solution you see here might be helpful, or in a language such as C++, the Chilkat solution isn't really necessary because it's easy to do yourself.

Ruby

require 'chilkat'

success = false

# This example assumes the Chilkat API to have been previously unlocked.
# See Global Unlock Sample for sample code.

charset = Chilkat::CkCharset.new()

charset.put_FromCharset("utf-8")
charset.put_ToCharset("bom-utf-8")

success = charset.ConvertFile("qa_data/txt/helloWorld.txt","qa_output/helloWorldBom.txt")
if (success != true)
    print charset.lastErrorText() + "\n";
    exit
end

print "Success." + "\n";