title: In Ruby on Rails, what does authenticate_with_http_basic do?
body: <p>Restful Authentication uses <code>authenticate_with_http_basic</code>, but a search on the net can find many pages with no description.  On the official <a href="http://api.rubyonrails.org/" rel="noreferrer">http://api.rubyonrails.org/</a>, it can also be found, except again there is no description, no comment, no spec.</p>
  
  <p>What does it do?  it seems to be able to use a <code>login_name</code> and <code>password</code> from an HTTP request and then they can be compared to the <code>login_name</code> and <code>encrypted_password</code> in the <code>users</code> table... but is that the case, why aren't there even a 1-line description?</p>