求一段php正则替换规则
/e/tags/index.php?page=23&tagname=%B9%D8%D3%DA%D3%D1%D2%EA%D5%E4%B9%F3%B5%C4%B8%F1%D1%D4&line=3&tempid=13

用preg_replace()把这样的替换成
/tag-%B9%D8%D3%DA%D3%D1%D2%EA%D5%E4%B9%F3%B5%C4%B8%F1%D1%D4/23/

当page=0的时候替换成
/tag-%B9%D8%D3%DA%D3%D1%D2%EA%D5%E4%B9%F3%B5%C4%B8%F1%D1%D4/
------解决方案--------------------

$str="/e/tags/index.php?page=0&tagname=%B9%D8%D3%DA%D3%D1%D2%EA%D5%E4%B9%F3%B5%C4%B8%F1%D1%D4&line=3&tempid=13";

$s= preg_replace_callback(

     '#.+?page=(\d+)&tagname=([^&]+)&.+#',

     create_function(

            '$matches',

            'return "/tag-$matches[2]/". ($matches[1] ? $matches[1]."/" : "");'

        ),

		$str

);

echo $s;

/tag-%B9%D8%D3%DA%D3%D1%D2%EA%D5%E4%B9%F3%B5%C4%B8%F1%D1%D4/