title: Count the number of digits in a bash variable
body: <p>I have a number <code>num=010</code>. I would like to count the number of digits contained in this number. If the number of digits is above a certain number, I would like to do some processing.</p>
  
  <p>In the above example, the number of digits is 3.</p>
  
  <p>Thanks!</p>