Displays gem urls and summaries found in a Gemfile

gemfile

#!/usr/bin/env ruby

# USAGE
#   gemfile [--bundle] [--details] [--fetch] [--sorted] [--commentate]
# DESCRIPTION
#   Displays gem urls and summaries found in a Gemfile.
#   cd into a directory with a Gemfile and run `gemfile`
# PREREQUISITES
#   gem install bundler paint
# FLAGS
#   bundle: Display all bundled gems (default is only top level dependencies)
#   details: Show gem descriptions
#   fetch: If a gem could not be found on the system, try to fetch its data from rubygems.org
#   sorted: Show in alphabetical order instead of the one in the Gemfile
#   commentate: Add gem descriptions to the __END__ section of your Gemfile

require 'rubygems' unless defined? Gem
require 'bundler' # gem install bundler
require 'open-uri'
require 'paint'   # gem install paint
require 'json'

if RUBY_VERSION >= "1.9.3"
  require 'io/console'
  width = STDIN.winsize[1]
else
  width = `stty size | cut -d" " -f2`.to_i
end

FakeSpec = Struct.new :name, :homepage, :description

bundle  = $*.delete '--bundle'
details = $*.delete '--details'
fetch   = $*.delete '--fetch'
sorted  = $*.delete '--sorted'
commentate = $*.delete '--commentate'

specs = 
  if bundle
    Bundler.load.specs
  else
    Bundler.definition.dependencies.map do |d|
      begin
        d.to_spec
      rescue Gem::LoadError
        Thread.new do
          homepage, description = "", ""
          if fetch
            begin
              gem_data = JSON.parse(open("https://rubygems.org/api/v1/gems/#{URI.escape(d.name)}.json").read)
              homepage, description = gem_data["homepage_uri"], gem_data["info"]
            rescue
            end
          end
          FakeSpec.new d.name, homepage, description
        end
      end
    end.map{ |t| t.respond_to?(:value) ? t.value : t }
  end

specs = specs.sort_by(&:name) if sorted

res = ""
specs.each{ |s|
  res << Paint[s.name, :bold]
  if s.homepage && !s.homepage.empty?
    res << "#{details ? " | " : " "}#{s.homepage}"
  end
  res << "\n"

  if details
    res << (s.description || s.summary).
      gsub(/\s+/m," ").
      gsub(/^ /,"").
      scan(/.{0,#{ width -2 }}(?:\s|\z)/).map{ |l| "  #{l}\n" }.join
  end
}

if commentate
  gemfile_source = File.read(Bundler.default_gemfile)

  really_do_it = true
  if gemfile_source =~ /^__END__/
    print 'There already is a data section defined in your Gemfile... replace? [Yn]'; question = gets
    if question =~ /\A[yY]?\n\z/
      File.open(Bundler.default_gemfile, 'w'){ |f|
        f.write gemfile_source.gsub(/\n?^__END__.*?\z/m, '')
      }
    else
      really_do_it = false
      puts 'Not updated'
    end
  end

  if really_do_it
    File.open(Bundler.default_gemfile, 'a'){ |f|
      f.write("\n__END__\n#{ Time.now.strftime(%[%e#{->o{%w[st nd rd][~-o%10]||%[th]}[Time.now.day]} of %B, %Y]) }\n\n#{ Paint.unpaint(res) }")
    }
    puts 'Appended gem information to your Gemfile'
  end
else 
  print res
end