正则表达式提取问题

Question

有以下字符串：http://item.taobao.com/auction/item_detail.jhtml?item_id=14e1677cfe49c9ef3ab1d260c4bf2007&ali_refid=a3_619362_1007:1102239684:7:%CC%D4%B1%A6%CA%D7%D2%B3%C8%C8%C2%F4%B5%A5%C6%B7sisa7try0423:6317a663071691c3ca70c5de55b62974&ali_trackid=1_6317a663071691c3ca70c5de55b62974
要提取item_id=后面的字符串，用正则表达式我这样写：
"http://item.taobao.com/auction/item_detail.jhtml?item_id=([0-9a-z]*)(.*?)"
在PHP中报错。Warning: ereg() [function.ereg]: REG_BADRPT 
错在哪了？

Answer 1

$url = "http://item.taobao.com/auction/item_detail.jhtml?item_id=14e1677cfe49c9ef3ab1d260c4bf2007&ali_refid=a3_619362_1007:1102239684:7:%CC%D4%B1%A6%CA%D7%D2%B3%C8%C8%C2%F4%B5%A5%C6%B7sisa7try0423:6317a663071691c3ca70c5de55b62974&ali_trackid=1_6317a663071691c3ca70c5de55b62974";
preg_match("#.*?item_id=(.*)#", $url, $match);
var_dump($match);