title: Use regex to match a series of numbers 1-9, with no repetition
body: <p>I need to be able to match a series of numbers, (any number between <code>1</code> and <code>9</code>), with as many different digits as the user enters but no repetition.</p>
  
  <blockquote>
    <p>123456789 -> match<br>
    1223 -> no match</p>
  </blockquote>
  
  <p>In effect, the number must be between 1 and 9 digits long, containing only numbers, and not repeat any digit.</p>
  
  <p><strong>How would I do this using regex?</strong></p>