Making Ruby into PHP

Sometimes a web framework is just over kill. Maybe it’s a one off dynamic page, maybe you don’t want the memory footprint of a whole framework running for only a small component of your whole site.

mod_ruby and eruby can get you a lot of what PHP gives you if you’re into that and don’t mind the setup. There’s the added perk that you won’t have to write PHP.

But what if you want something similar, but quick and simple and you’re willing to use CGI? Here’s a neat little trick.

First save this text into a file called “rubyhp.rb” in your cgi-bin directory. 

require 'erb'
require 'cgi'

cgi = CGI.new
print "Content-type: text/html\n\n"
print ERB.new(DATA.read).result(binding)

Leave this file unexecutable, so your web server won’t serve it. Then create your PHP style Ruby file like this. 

#!/usr/bin/ruby                                                                 
require 'rubyhp'
__END__
<html>
 <body>
  <% cgi.params.each do |key, value| %>
   <%= key %>: <%= value %><br />
  <% end %>
  <% if cgi.params.empty? %>
   Sorry, please enter some cgi parameters. How about "?foo=baz"?
  <% end %>
 </body>
</html>

Name this file “test.rb” and save it in your same cgi-bin directory. Make it executable and you’re done. You can write whatever erb you want after the __END__ line, without needing to worry about setting up anything fancy. And you have access to a parsed CGI object through the variable ‘cgi’.

Does CGI still have a place in modern web work? I’m don’t know. But I do still use it for quick dynamic pages on cyll.org like the Computer Science Bandname Generator. This little trick makes life a little easier for me when I do.

8/26/2006