System configuration

gistfile1.rb

#!/usr/bin/env ruby
=begin
To run, copy and paste the following command into a console:
ruby < <(curl -s https://raw.github.com/gist/1816919/469a4086833ce3b3496476aef1246c5d81b7ac99/gistfile1.rb)

And shucks, if that doesn't work, there's always this:
bash --version && \
brew --version && \
bundle --version && \
curl --version && \
git --version && \
openssl version && \
sw_vers -productVersion && \
ruby --version && \
gem --version && \
rvm --version
=end
PROGRAMS = {
  "bash"     => "bash --version",
  "Bundler"  => "bundle --version",
  "curl"     => "curl --version",
  "git"      => "git --version",
  "Homebrew" => "brew --version",
  "OpenSSL"  => "openssl version",
  "OSX"      => "sw_vers -productVersion",
  "Ruby"     => "ruby --version",
  "RubyGems" => "gem --version",
  "RVM"      => "rvm --version"
}
NOT_INSTALLED = /command not found/
VERSION_PART = /\d+\.[\d.]+(?:b|p|r|rc|\()?(?:\d*)\)?/

longest_key = PROGRAMS.keys.map(&:size).max
PROGRAMS.each do |name, command|
  padding = " " * (longest_key - name.size)
  result = %x[#{command} 2>&1]  

  if result =~ NOT_INSTALLED
    version = "not installed"
  else
    version = result[VERSION_PART]
  end
  puts "#{name}: #{padding}#{version}"
end