/**
 * 字串擷取，支援中文和其他編碼
 * @static
* @access public
 * @param string $str 需要轉換的字串
 * @param string $start 開始位置
 * @param string $length 擷取長度
 * @param string $charset 編碼格式
 * @param string $suffix 截斷顯示字元
 * @return string
 */
function msubstr($str, $start = 0, $length, $charset = "utf-8", $suffix = true)
 
{
if (function_exists("mb_substr"))
$slice = mb_substr($str, $start, $length, $charset);
elseif (function_exists('iconv_substr')) {
$slice = iconv_substr($str, $start, $length, $charset);
if (false === $slice) {
$slice = '';
}
    } else {
$re['utf-8'] = "/[\x01-\x7f]|[\xc2-\xdf][\x80-\xbf]|[\xe0-\xef][
 
\x80-\xbf]{2}|[\xf0-\xff][\x80-\xbf]{3}/";
$re['gb2312'] = "/[\x01-\x7f]|[\xb0-\xf7][\xa0-\xfe]/";
$re['gbk'] = "/[\x01-\x7f]|[\x81-\xfe][\x40-\xfe]/";
$re['big5'] = "/[\x01-\x7f]|[\x81-\xfe]([\x40-\x7e]|\xa1-\xfe])/";
preg_match_all($re[$charset], $str, $match);
$slice = join("", array_slice($match[0], $start, $length
 
));
}
//字數不滿不新增...
$count = mb_strlen($str, 'utf-8');
if ($count > $length) {
return $suffix ? $slice . '...' : $slice;
} else {
return $slice;
}
}