title: sed extract digits
body: <p>I try to extract digits with sed:</p>
  
  <pre><code>echo hgdfjg678gfdg kjg45nn | sed 's/.*\([0-9]\+\).*/\1/g'
  </code></pre>
  
  <p>but result is:
  5
  How to extract: 678 and 45?
  Thanks in advance!</p>