title: How to get df linux command output always in GB
body: <p>How to get df linux command output always in GB always? 
  ie. I want below 34MB to be displayed in GBs</p>
  
  <pre><code>Filesystem            Size  Used Avail Use% Mounted on
  /ttt/pda1              21G   20G   34M 100% /
  </code></pre>
  
  <p>How can this be achieved ?</p>
  
  <p>Thanks in advance.</p>