convert.rb

# Convert a Gemfile to Heroku's .gems file plus config.gem statements for Rails 2.3

herokuconfig = ""
railsconfig = ""
gemfile = File.new("Gemfile")
gemfile.readlines.each do |line|
  if line =~ /gem ['"](\w+)['"](?:, ['"](.+?)['"]){0,1}(?:, :require => ['"](.+?)['"]){0,1}/
    herokuconfig << "#{$1}" + ($2 ? %Q( --version "#{$2}") : '') + "\n"

    railsconfig << "config.gem '#{$1}'" + ($2 ? ", :version => '#{$2}'" : '') + ($3 ? ", :lib => '#{$3}'" : '') + "\n"
  end
end

puts herokuconfig
puts railsconfig