Lua

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.

Lua

local chilkat = require("chilkat")

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

local charset = chilkat.Charset.new()

charset.from_charset = "utf-8"
charset.to_charset = "bom-utf-8"

local success = charset:convert_file("qa_data/txt/helloWorld.txt", "qa_output/helloWorldBom.txt")
if not success then
    print(charset.last_error_text)
    return
end

print("Success.")