preg_replace_callback轮换preg_replace

preg_replace_callback替换preg_replace
$tem = $arr['invoice_type'];
echo "

";
print_r($tem);

输出
a:2:{s:4:"type";a:3:{i:0;s:8:"个人发票";i:1;s:8:"企业发票";i:2;s:0:"";}s:4:"rate";a:3:{i:0;d:6;i:1;d:6;i:2;d:0;}}

$teem []= preg_replace('!s:(\d+):"(.*?)";!se', "'s:'.strlen('$2').':\"$2\";'", $arr['invoice_type'] );
echo "

";
print_r($teem);

输出
Array
(
[0] => a:2:{'s:'.strlen('type').':"type";'a:3:{i:0;'s:'.strlen('个人发票').':"个人发票";'i:1;'s:'.strlen('企业发票').':"企业发票";'i:2;'s:'.strlen('').':"";'}'s:'.strlen('rate').':"rate";'a:3:{i:0;d:6;i:1;d:6;i:2;d:0;}}
)

$teemm []= preg_replace_callback('!s:(\d+):"(.*?)";!s', function ($matches) {return strlen('$2').':\"$2\";';}, $arr['invoice_type'] );
echo "

";
print_r($teemm);

输出
Array
(
[0] => a:2:{2:\"$2\";a:3:{i:0;2:\"$2\";i:1;2:\"$2\";i:2;2:\"$2\";}2:\"$2\";a:3:{i:0;d:6;i:1;d:6;i:2;d:0;}}
)

如何让preg_replace_callback输出的信息和preg_replace输出的一样
------解决方案--------------------

$s = preg_replace_callback('/s:\d+:"(.+?)";/s',
		function($r) {
			$n = strlen($r[1]);
			return "s:$n:\"$r[1]\";";
		}, $s);