title: Update with $push MongoDB using bash script
body: <p>I am using a bash script to update my mongoDB. Here is the code I use:</p>
  
  <pre><code>mongo 127.0.0.1/foo --eval 'db.coll.update({"Name1": '"$arg1"', "Name2": '"$arg2"'}, {$push: {"Name3": '"$arg3"'}}, {upsert: true});'
  </code></pre>
  
  <p>The code above should update if existing document which is matching Nam1 and Name2. The value to update is arg3 in field Name3. This value is pushed, which means a new value is appended to the existing list.</p>
  
  <p>But I get the error code: </p>
  
  <blockquote>
    <p>SyntaxError: Unexpected number</p>
  </blockquote>
  
  <p>What am I doing wrong?</p>