title: Using three grep commands to sort and alphabetically order
body: <p>I created the file ~/firstredhat.txt. </p>
  
  <p>How do I make an alphabetically sorted list of all files underneath the /usr/share/firstboot directory (and its subdirectories) that contain the text redhat, using a case insensitive search?</p>
  
  <p>The files should be listed one per line using absolute references.</p>