title: extract substring until first digit
body: <p>I have the following string: </p>
  
  <p><code>test1234a</code> or <code>test1234</code> for example and I want to extract only <code>test</code> from that string.</p>
  
  <p>I tried the follwing</p>
  
  <pre><code>echo "Test12h" | sed -e 's/[0-9]\*$//' but is not working. 
  </code></pre>
  
  <p>Is there any possibility to extract the substring until first digit?</p>
  
  <p>Please let me know what I miss. </p>
  
  <p>Thank you</p>