phpjs/experimental/stream/stream_default_encoding.js

php.js offers community built php functions in javascript

function stream_default_encoding(encoding) {
  // http://kevin.vanzonneveld.net
  // +   original by: Brett Zamir (http://brett-zamir.me)
  // %        note 1: Not yet documented at PHP site
  // *     example 1: stream_default_encoding('UTF-8');
  // *     returns 1: true

  this.ini_set('unicode.stream_encoding', encoding);
  return true;
}