title: Dereferencing variables within ruby regex
body: <p>I am having trouble figuring this one out. I need to be able to dereference an integer variable in ruby within a regex. So, for example, lets say I have a string called this_string, and I want to insert a space every 8 characters, this would work:</p>
  
  <pre><code>this_string.scan(/.{8}|.+/).join(" ")
  </code></pre>
  
  <p>But how do I do this every N characters using a regex, where N is an arbitrary integer?</p>