title: insert a line in csv file
body: <p>I have a  huge csv file (on order of terabytes).</p>
  
  <p>Now, I want to insert one row which is a header to the the top.</p>
  
  <p>For example if input.csv looks like this:</p>
  
  <pre><code> 1,2,3,4
   22,3,23,1
  </code></pre>
  
  <p>I want it to look like</p>
  
  <pre><code>id1,id2,id3,id4
   1,2,3,4
   and so on
  </code></pre>
  
  <p>How do i do this from shell, terminal, awk, bash?/</p>