code: function readDirAbs(dir, cb) {
    fs.readdir(dir, function(err, entries) {
      if (err || !entries) {
        return cb(err, null);
      }
      var items = [];
      entries.forEach(function(entry) {
        items.push(path.join(dir, entry));
      });
      return cb(null, items);
    });
  }
docs: return abs paths