- print_r: documentation ( source)
- preg_match_all: documentation ( source)
<?php
$url = 'http://weibo.com/1948452141/BAlOHzDS3?ref=home&rid=7_0_2598638016537367410';
$pattern = "/.*weibo.com\/\d+\/(\w+)\?.*/";
preg_match_all($pattern, $url, $arr);
print_r($arr);