Rails Root directory path?

For super correctness, you should use:

Rails.root.join('foo','bar')

which will allow your app to work on platforms where / is not the directory separator, should anyone try and run it on one.

In Rails 3 and newer:

Rails.root

which returns a Pathname object. If you want a string you have to add .to_s. If you want another path in your Rails app, you can use join like this:

Rails.root.join('app', 'assets', 'images', 'logo.png')

In Rails 2 you can use the RAILS_ROOT constant, which is a string.