limit characters wp

function limit_char($limit, $source=null) {
  global $post;
  ($source) ? '<p>'.$source.'</p>' : $source = '<p>'.get_the_excerpt().'</p>';
  $read_more = '...  <a href="'. get_permalink($post->ID) . '" class="more-link" title="Read '.get_the_title($post->ID).'">Read more</a>';
  $limited = strlen($source) > $limit ? substr($source,0,strpos($source,' ',$limit)) . $read_more : $source;
  echo $limited;
}