title: Removing last comma using sed
body: <p>I have a text file and I want to remove the last comma , from the second last line if exist.</p>
  
  <pre><code>a, b, c, d,
  m, n, p,
  x, y, z,
  );
  </code></pre>
  
  <p>The comma after z needs be removed only.</p>