NodeJS Prevent Local File Inclusion and NULL byte attack

gistfile1.js

String.prototype.safe = function() {
	var s = this.toString().split("/"), r = [];
	for(var a in s) {
		if(s[a] != "..")
			r.push(s[a]);
	}
	r = r.join("/");
	var i = r.indexOf("\0");
	if(i > 0)
		r = r.substr(0, i);
	return(r);
};