what is simplest way to convert Request-URI to lowercase?

[Anh K. Huynh]

Hello,

We are using nginx heavily. We need to rewrite all request URIs
into lowercase, e.g,

  http://foo.bar/ThiS_will_be_Rewritten/?q=Foobar

will be translated into

  http://foo.bar/this_will_be_rewritten/?q=foobar

I know some modules (Perl, Lua) can do this. My question is
what the simplest way (module) to do that, because Perl/Lua
seems to be overkill here ;)

Thank you very much.

--
I am ... 5.5 dog years old.