title: How to grep the number in text file?
body: <p>i want to ask a question about 'awk' , example:</p>
  
  <pre><code>awk '{print $8}' tes.txt
  
  output : size=21341,
  </code></pre>
  
  <p>but i only want to grep number "21341", can you give me solution about how to grep the number?</p>