title: One liner to rename bunch of files
body: <p>I was looking for a linux command line one-liner to rename a bunch of files in one shot.</p>
  
  <pre><code>pattern1.a  pattern1.b pattern1.c ...
  </code></pre>
  
  <p>Once the command is executed I should get</p>
  
  <pre><code>pattern2.a  pattern2.b pattern2.c ...
  </code></pre>