title: compare portion of the string using php
body: <p>I want to check whether the search keyword 'cli' or 'ent' or 'cl' word exists in the string 'client' and case insensitive. I used the preg_match function with the pattern '\bclient\b'. but it is not showing the correct result. Match not found error getting. </p>
  
  <p>Please anyone help</p>
  
  <p>Thanks</p>