忽略大小写（刚在nginx的maillist看到的）

The first option (with the if and http://$host) sends an HTTP redirect
to the lowercase URL if the requested URL is not completely in
lowercase. I like this approach better as it kind of normalizes all URL
to a canonical form.. The second option (without if nor http://) just accepts
any URL and internally rewrites them to lowercase: if you rename all
your directories and files to lowercase, this will imitate Windows'
case-insensitive behaviour.

Kudos to the following post were I
draw the "inspiration" :D from to get this done. The embedded perl doc
and examples are indeed scarce. :-(

- you need the
embedded perl module which according to the docs is experimental and can
lead to memory leaks.

- the actual redirection is done with the
rewrite, which you can put on the location you need. But the URL
lowercase calculation, being on the "http" section of the config, is
done for each and every request arriving to your server. Say you have a
virtual server with 10 domains and you only need this on one particular
location of one of them. The lowercase URL is going to be calculated for
every request of every domain.

I guess that by defining a perl
function the URL calculation could be restricted to a particular
location, have to look into it further. Another option is writing a C
module.