using Thin web server configuration in development , how to have eq. Apache RedirectMatch permanent

In production, using Apache I can use RedirectMatch permanent to force url wo subdomain to use www.

<VirtualHost *:80>

ServerName example.com

RedirectMatch permanent ^/(.*) http://www.example.com/$1

How can I get the same behavior when using Thin in dev mode ?

need to change all example.com/… urls into www.example.com/… if I don’t want to touch the routes ?

thanks for feedback

[SOLVED] but using Rails3 routes, maybe there is a better way ?

host = Rails.application.config.action_mailer.default_url_options[:host]

constraints(:host => host ) do

root :to => redirect(“http://www.#{host}”)

match ‘/*path’, :to => redirect {|params| “http://www.#{host}/#{params[:path]}”}

end