title: What is the command for replacing strings in CodeIgniter
body: <p>What is the command for replacing strings in CodeIgniter
  for example</p>
  
  <p>Original string is www.example.com/imges/fraudsite.html</p>
  
  <p>Replace string is www.example.com/imges/fraudsite.zip</p>
  
  <p>just want to replace all after (dot)</p>
  
  <p>Thanks
  Sodmeb</p>