title: Padding zeros in a string
body: <p>I'm writing a bash script to get some podcasts.  The problem is that some of the podcast numbers are one digits while others are two/three digits, therefore I need to pad them to make them all 3 digits.</p>
  
  <p>I tried the following:</p>
  
  <pre><code>n=1
  
  n = printf %03d $n
  
  wget http://aolradio.podcast.aol.com/sn/SN-$n.mp3
  </code></pre>
  
  <p>but the variable 'n' doesn't stay padded permanently.  How can I make it permanent?</p>