nginx rewrite的规则要怎么写？

lff642

nginx rewrite的规则要怎么写？
我想通过rewrite把 http://www.abc.com/bbs/viewthrea ... ra=&ordertype=2
类似的链接301重定向到 http://bbs.abc.com/viewthread.ph ... ra=&ordertype=2
该怎么写呢？

black-hat

rewrite ^/bbs(.*)$    http://bbs.abc.com/$1 permanent;