gistfile1.txt

#!/usr/bin/env ruby
require 'webrick'
include WEBrick
require 'erb'

s = HTTPServer.new( :Port => 3000,:DocumentRoot    => Dir::pwd + '/' + (ARGV[0] || '.'))

class ErbServlet < HTTPServlet::AbstractServlet
  def do_GET(req, response)
    File.open(ARGV[0],'r') do |f|
     @template = ERB.new(f.read)
    end
    response.body = @template.result(binding)
    response['Content-Type'] = "text/html"
  end
end

s.mount("/", ErbServlet)

trap("INT"){
  s.shutdown
}
s.start