title: Numbering lines matching the pattern using sed
body: <p>I'm writing the script that searches for lines that match some pattern. I must use sed for this script.
  This works fine for searching and printing matched lines:</p>
  
  <pre><code>sed -n /PATTERN/p
  </code></pre>
  
  <p>However, I'd also like to print the matched lines number in front of the line itself.
  How can I do that using sed?</p>