rewrite to www EXCEPT for one directory

[eddy at sdf.org]

> On Friday 07 September 2012 00:32:48 eddy at sdf.org wrote:

> And please do not use ugly rewrites instead of simple "return", where it's
> possible.
>
>  wbr, Valentin V. Bartenev

maybe it's a stupid question, but: if 'permanent - returns permanent
redirect with code 301' (http://wiki.nginx.org/HttpRewriteModule), then
why one should use 'return 301 URL' instat?

or its more about to avoid rewriting rules generaly? if yes, why is this
so? a few weeks ago, i followed a discussion about to avoid if-rules
because of performance with large rule sets. but i can't see this argument
with one rewriting rule, which only takes action at first connect from
client to server.

it's just a little bit confusing for me 'cause of so many poorly writen
config examples around the web, and it's the first time i see this way
with 'return 301 URL' for redirecting example.org to www.example.org.

~ed