title: add row number to the last column using awk or bash
body: <p>Input file format:</p>
  
  <pre><code>name id department
  xyz  20  cic
  abc  25  cis
  </code></pre>
  
  <p>Output should look like:</p>
  
  <pre><code>name id department
  xyz  20  cic        1
  abc  25  cis        2
  </code></pre>
  
  <p>Note: all the fields are tab separated.</p>
  
  <p>Appreciate any help!!</p>