Quick, ugly script to grep rails projects for rails versions, as suggested by @Govan - https://twitter.com/gavinmontague/status/408252762330517506

rails_versions.rb

#!/usr/bin/env ruby

TERMINAL_RED     = 31
TERMINAL_GREEN   = 32
TERMINAL_DEFAULT = 0
LATEST_RAILS_VERSIONS = {
  '2.3' => '2.3.18',
  '3.0' => '3.0.20',
  '3.1' => '3.1.12',
  '3.2' => '3.2.16',
  '4.0' => '4.0.2'
}

if ARGV[0] == nil
  STDERR.puts 'Usage: rails_versions <Folder containing all rails projects> # e.g. rails_versions ~/work/'
  abort
end

root = File.expand_path(ARGV[0])
root_for_grep = File.join(root, '**', 'Gemfile.lock')
rails_regex = "^    rails "

raw_results = `grep -nrs "#{rails_regex}" #{root_for_grep}`

results = raw_results.split($/).map do |r|
  split = r.split(' ')

  version = split.last.scan(/\((.+)\)/).flatten.first
  latest_rails_version = LATEST_RAILS_VERSIONS[version.scan(/\d+\.\d+/).flatten.first]
  path_split = split.first.split('/')
  path_split.pop
  app_name = path_split.pop

  [app_name, { current: version, latest: latest_rails_version }]
end

app_versions = Hash[*results.flatten]

if app_versions.empty?
  abort
end

STDERR.puts "App name          \tCurrent\tLatest\tOut of date"
app_versions.each do |app_name, versions|

  output = []

  up_to_date = versions[:current] == versions[:latest]
  colour = up_to_date ? TERMINAL_GREEN : TERMINAL_RED

  output << "\e[#{colour}m#{app_name.ljust(20)}"

  output << "#{versions[:current]}"
  output << "\e[0m#{versions[:latest]}"
  output << "*" unless up_to_date

  STDOUT.puts output.join("\t")
end