title: Add commas to list of JSON object
body: <p>I have text file who contains a list of objects.</p>
  
  <pre><code>{ a:"1", b:"2", c: "3"}{ a:"1", b:"2", c: "3"}{ a:"1", b:"2", c: "3"}
  </code></pre>
  
  <p>I want to make it valid Json file. For instanse:</p>
  
  <pre><code>[{ a:"1", b:"2", c: "3"},{ a:"1", b:"2", c: "3"},{ a:"1", b:"2", c: "3"}]
  </code></pre>
  
  <p>The file is very big - 600mb. I need to do this with languages who can change files. I tried to find solution but I couldn't. </p>