script/console for Your Application

Rails developers know and love script/console. It fires up an interactive session where you can poke around your application through the models you've built. It's invaluable for debugging and surprisingly handy for administration. But not all Ruby applications are Rails applications. Wouldn't it be nice to have a script/console anyway?

Turns out it's dead easy to build one.

First, decide which libraries and files you want loaded. This almost always includes RubyGems and some kind of boot file for your application. I usually keep mine in config/boot.rb.

Here's an example boot.rb:

require 'rubygems'
require 'hpricot'
require 'net/http'
require File.dirname(__FILE__) + '/../vendor/gems/activecouch/init'

$: << File.dirname(__FILE__) + '/../app/models'

ActiveCouch::Base.class_eval do
  set_database_name 'blog'
  site 'http://localhost:5984/'
end

require 'article'
require 'comment'
require 'author'

With that in place, create a Ruby script that launches IRb, requires the right files, and sets a clean prompt. I like to print a welcome banner too, because why not.

#! /usr/bin/env ruby

libs = []
libs << "irb/completion"
libs << File.dirname(__FILE__) + '/../config/boot.rb'

command_line = []
command_line << "irb"
command_line << libs.inject("") { |acc, lib| acc + %( -r "#{lib}") }
command_line << "--simple-prompt"
command = command_line.join(" ")

puts "Welcome to the  console interface."
exec command

Drop that into script/console, chmod +x it, and commit. That's it — instant application console for any Ruby project.