title: Searching a CSV File Using Grep
body: <p>Lets say I have a csv file like this:</p>
  
  <pre><code>a,b1,12,
  a,b1,42,
  d,e1,12,
  r,12,33,
  </code></pre>
  
  <p>I want to use grep to return only only the rows where the third column = 12. So it would return:</p>
  
  <pre><code>a,b1,12,
  d,e1,12,
  </code></pre>
  
  <p>but not:</p>
  
  <pre><code>r,12,33,
  </code></pre>
  
  <p>Any ideas for a regular expression that will allow me to do this?</p>