- strpos: documentation ( source)
- htmlentities: documentation ( source)
- preg_replace: documentation ( source)
<?php
$search = htmlentities("(apple|phpinfo())/e\0");
if (strpos($search, 'apple') !== false){
echo preg_replace("/".$search."/", $search, "apple");
}else echo "Please search for apple, orange, banana, or kiwi.";