title: Unix command to convert xls file into xlsx file?
body: <p>I there any unix command which will convert xls file into xlsx file?</p>
  
  <p>Also i have tried using mv command, it is changing the extension as well. But then i am not able to open the xlsx file.</p>
  
  <pre><code>mv .xls .xlsx
  </code></pre>
  
  <p>Any suggestion will be really appreciate.</p>