我有一个字符串形如：img[http://xxx.com/a.png]好可爱的图片，我再来一张img[http://xxx.com/b.png],用正则怎么提取图片路径呢？
[a-zA-z]+://[^\s]*
匹配URL地址。
![http://xxx.com/a.png]好可爱的图片，我再来一张img[http://xxx.com/b.png],用正则怎么提取图片路径呢？](http://xxx.com/a.png%5D%E5%A5%BD%E5%8F%AF%E7%88%B1%E7%9A%84%E5%9B%BE%E7%89%87%EF%BC%8C%E6%88%91%E5%86%8D%E6%9D%A5%E4%B8%80%E5%BC%A0img%5Bhttp://xxx.com/b.png%5D,%E7%94%A8%E6%AD%A3%E5%88%99%E6%80%8E%E4%B9%88%E6%8F%90%E5%8F%96%E5%9B%BE%E7%89%87%E8%B7%AF%E5%BE%84%E5%91%A2%EF%BC%9F){kind=link}