<?php 
function cutstr($str, $i)
{
   $str = htmlspecialchars($str);

   if (strlen($str) > $i)
   {
      $str = substr($str, 0, $i);
      $str .= " ...";
   }

   return $str;
}
$string = 'Length of This Line is Larger Then 15 And I Want To Cut It';
print '<b>Original Text: </b>'.$string.'</br>'; //Output:
echo cutstr($string,15);
?>