I want to log user's ip address, referer, and user agent.
In PHP, I can get them from the following variables:
$_SERVER['REMOTE_ADDR']
$_SERVER['HTTP_REFERER']
$_SERVER['HTTP_USER_AGENT']
How to get them in ruby?
PHP is embedded in a web server. Ruby is a general-purpose language: if you need a web server context, you'll have to install it yourself. Fortunately, it's easy.
One of the easiest ways to get started is with Sinatra. Install the gem:
gem install sinatra
Then create myapp.rb:
require 'sinatra'
get '/' do
request.user_agent
end
Start up the web server:
ruby -rubygems myapp.rb
Visit Sinatra's default URL: http://localhost:4567/
Et voilà.