Dart

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.

Dart

import 'package:chilkat/chilkat.dart';

void main() {
  // This example assumes the Chilkat API to have been previously unlocked.
  // See Global Unlock Sample for sample code.

  final charset = CkCharset();

  charset.fromCharset = 'utf-8';
  charset.toCharset = 'bom-utf-8';

  try {
    charset.convertFile('qa_data/txt/helloWorld.txt', 'qa_output/helloWorldBom.txt');
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  print('Success.');
}