title: find difference between two text files with one item per line
body: <p>I have two files:</p>
  
  <p>file 1</p>
  
  <pre><code>dsf
  sdfsd
  dsfsdf
  </code></pre>
  
  <p>file 2</p>
  
  <pre><code>ljljlj 
  lkklk 
  dsf
  sdfsd
  dsfsdf
  </code></pre>
  
  <p>I want to display what is in file 2 but not in file 1, so file 3 should look like</p>
  
  <pre><code>ljljlj 
  lkklk 
  </code></pre>