title: Given an input with a period, how to get everything trailing it?
body: <p>Given inputs like the following</p>
  
  <pre><code>bob - invalid
  bob. - invalid
  bob.edu - valid
  bob.com - valid
  bob.newco.com - valid
  </code></pre>
  
  <p>In Ruby, I'd like a way to first determine if there is a period, if there is I want everything after the last period?</p>
  
  <p>I tried doing </p>
  
  <pre><code>domain_ext = search_input.split('.').last
  </code></pre>
  
  <p>Problem is, if the input is <code>roger.</code> that is returning 5, thinking <code>roger</code> is the ext. I don't know how to tell Ruby only after the last period?</p>