- preg_replace: documentation ( source)
<?php
$temp = " hello th*ere-----------how are you--au!@&*--";
//$temp = strtolower($temp);
//$temp = preg_replace('/\s+/',' ', $temp);
$temp = preg_replace('/\s+/', '-', $temp);
$temp = preg_replace('/([^\w-])\-$/', '~', $temp);
//$temp = trim($temp);
//$temp = preg_replace('/\s+/', '-', $temp);
echo($temp);