>> Well,when i want to use property in the regexp,ruby does complain that
>> bad property,but i never find any good property it accepts.Now i have a
>> question,does it support unicode property,such as \p{Han}??Or is it just
>> dummy?

I put together http://redmine.ruby-lang.org/repositories/entry/ruby-19/doc/re.rdoc
which explains the supported properties. If you've got a recent build
of 1.9, it's accessible as `ri Regexp`.