title: How to sort on column for rows containing a certain word
body: <p>I want to sort on a certain column only  for rows containing a certain word. I don't want to see rows not containing that word. For example I have this text file:</p>
  
  <pre><code> sdf ggfds   7
   sdf sgs     5
   sdf dfgs    3
   foo dffg    2
   bar dffg    2
   sdf sddfg   4
  </code></pre>
  
  <p>I want to sort 3rd column for rows containing only "sdf" word (doesnt have to be in a first column)</p>
  
  <p>and I want to see this output:</p>
  
  <pre><code> sdf dfgs    3
   sdf sddfg   4
   sdf sgs     5
   sdf ggfds   7
  </code></pre>