title: Difference between two lists using Bash
body: <p>Ok, I have two related lists on my linux box in text files:</p>
  
  <pre><code> /tmp/oldList
   /tmp/newList
  </code></pre>
  
  <p>I need to compare these lists to see what lines got added and what lines got removed. I then need to loop over these lines and perform actions on them based on whether they were added or removed.</p>
  
  <p>How do I do this in bash?</p>