title: Linux: How to output directory size as a number excluding directory path
body: <p>How do output the directory size in Linux?</p>
  
  <p>I am currently using "du /root/test" but I get the following result:</p>
  
  <p>754 /root/test</p>
  
  <p>I need to output only the number like:</p>
  
  <p>754</p>