title: Multi-domain routing/redirecting
body: <p>I have 6 domain names. Lets say:</p>
  
  <pre><code>www.abc.com
  www.abc1.com
  www.abc2.com
  www.abc3.com
  www.abc4.com
  www.abc5.com
  </code></pre>
  
  <p>But I have only one php hosting for www.abc.com
  I redirected all pages to www.abc.com</p>
  
  <p>How can I detect that which domain name the visitor came from?</p>