title: Insert rows using awk
body: <p>How can I insert a row using awk?</p>
  <p>My file looks as:</p>
  <pre><code>1       43
  2       34
  3       65
  4       75
  </code></pre>
  <p>I would like to insert three rows with &quot;?&quot; So my desire file looks as:</p>
  <pre><code>1       ?
  2       ?
  3       ?
  4       43
  5       34
  6       65
  7       75
  </code></pre>
  <p>I am trying with the below script.</p>
  <pre><code>awk '{if(NR&lt;=3){print &quot;NR        ?&quot;}} {printf&quot; &quot; NR      $2}' file.txt
  </code></pre>