How to cut the string without breaking any words

<?php
function Cut($string, $max_length){
	if (strlen($string) > $max_length){
		$string = substr($string, 0, $max_length);
		$pos = strrpos($string, " ");
		if($pos === false) {
				return substr($string, 0, $max_length)."...";
		}
			return substr($string, 0, $pos)."...";
	}else{
		return $string;
	}
}

$string = 'How to cut the string without breaking any words';
echo Cut($string,30);

?>

The output is

Author: admin