gistfile1.js

var cutString = function(s, width, trail) {
	if (typeof trail == 'undefined') trail = '…';
	var w = 0;
	for (var i = 0; i < s.length; ++i) {
		// we approximate east-asian width using the most prevalent ideographic blocks
		w += (s.charAt(i).match(/[\u3000-\u9fff\uac00-\ud7ff\uf900-\ufaff]/) ? 2 : 1);
		if (w > width) return s.substring(0, i) + trail;
	}
	return s;
};