title: move a specific column down using awk
body: <p>how can I move second column one row down as shown in the below example?</p>
  
  <pre><code>&gt; input
  n an na na
  a ae 1 2 3
  b be 3 2 1
  c    4 4 4
  
  &gt; output
  n  na na
  a an 1 2 3
  b be 3 2 1
  c be 4 4 4
  </code></pre>