# File lib/rubygems/gem_commands.rb, line 1297
    def execute
      out = ''
      arg = options[:args][0]
      if begins?("packageversion", arg)
        out = Gem::RubyGemsPackageVersion.to_s
      elsif begins?("version", arg)
        out = Gem::RubyGemsVersion.to_s
      elsif begins?("gemdir", arg)
        out = Gem.dir
      elsif begins?("gempath", arg)
        Gem.path.collect { |p| out << "#{p}\n" }
      elsif begins?("remotesources", arg)
        require 'sources'
        out << Gem.sources.join("\n") << "\n"
      elsif arg
        fail Gem::CommandLineError, "Unknown enviroment option [#{arg}]"
      else
        out = "RubyGems Environment:\n"
        out << "  - VERSION: #{Gem::RubyGemsVersion} (#{Gem::RubyGemsPackageVersion})\n"
        out << "  - INSTALLATION DIRECTORY: #{Gem.dir}\n"
        out << "  - GEM PATH:\n"
        Gem.path.collect { |p| out << "     - #{p}\n" }
        out << "  - REMOTE SOURCES:\n"
        require 'sources'
        Gem.sources.collect do |s|
          out << "     - #{s}\n"
        end
      end
      say out
      true
    end