Laravel与CI框架中截取字符串函数

function limit($value, $limit = 100, $end = '...'){  if (mb_strwidth($value, 'UTF-8') <= $limit) {    return $value;  }  return rtrim(mb_strimwidth($value, 0, $limit, '', 'UTF-8')).$end;}

function word_limiter($str, $limit = 100, $end_char = '…'){  if (trim($str) === '')  {    return $str;  }  preg_match('/^/s*+(?:/S++/s*+){1,'.(int) $limit.'}/', $str, $matches);  if (strlen($str) === strlen($matches[0]))  {    $end_char = '';  }  return rtrim($matches[0]).$end_char;}