code: function obj(argv, callback) {
    var uri = argv[2];
  
    if (argv[3]) {
      util.put(argv[2], '<> <> """' + argv[3] + '""" .', function(err, callback){
        if (err) {
          console.error(err);
        } else {
          console.log('put value : ' + argv[3]);
        }
      });
    } else {
      var wss = 'wss://' + uri.split('/')[2] + '/';
  
      var s = new ws(wss, {
        origin: 'http://websocket.org'
      });
  
      s.on('open', function open() {
        s.send('sub ' + uri);
      });
  
      s.on('close', function close() {
        console.log('disconnected');
      });
  
      s.on('message', function message(data, flags) {
        var a = data.split(' ');
        if (a.length && a[0] === 'pub') {
          util.getAll(a[1], function(err, res) {
            if (err) {
              callback(err);
            } else {
              callback(null, res[res.length-1].object.value);
            }
          });
        }
      });
    }
  }
docs: obj gets list of files for a given container
  
  @param {String} argv[2] url
  @callback {bin~cb} callback