title: bash cat multiple files
body: <p>I am trying to <code>cat</code> three files and obtain and insert a newline <code>\n</code> 
  after each file ,I thought of using something like :</p>
  
  <pre><code>cat f1 f2 f3|tr "\EOF" "\n"
  </code></pre>
  
  <p>without success.</p>
  
  <p>What is the easiest way to achieve that ?</p>