root@mongodb-lab-01:~# cat test2.js 
Date()
use admin;
db.auth("santanaj","password")
db.getUsers()
use db01;
db.mycoll.find()
root@mongodb-lab-01:~# mongo < test2.js 
MongoDB shell version v3.4.4
connecting to: mongodb://127.0.0.1:27017
MongoDB server version: 3.4.4
Thu Apr 27 2017 10:50:15 GMT+0200 (CEST)
switched to db admin
1
[
	{
		"_id" : "admin.santanaj",
		"user" : "santanaj",
		"db" : "admin",
		"roles" : [
			{
				"role" : "root",
				"db" : "admin"
			}
		]
	}
]
switched to db db01
{ "_id" : ObjectId("5901a8eaaaae00c4a0faa95a"), "ticket" : "SERVER-28956" }
bye
root@mongodb-lab-01:~#