execute

# File lib/rubygems/commands/specification_command.rb, line 56
  def execute
    specs = []
    gem = options[:args].shift

    unless gem then
      raise Gem::CommandLineError,
            "Please specify a gem name or file on the command line"
    end

    case options[:version]
    when String
      req = Gem::Requirement.parse options[:version]
    when Gem::Requirement
      req = options[:version]
    else
      raise Gem::CommandLineError, "Unsupported version type: #{options[:version]}"
    end

    if !req.none? and options[:all]
      alert_error "Specify --all or -v, not both"
      terminate_interaction 1
    end

    if options[:all]
      dep = Gem::Dependency.new gem
    else
      dep = Gem::Dependency.new gem, options[:version]
    end

    field = get_one_optional_argument

    raise Gem::CommandLineError, "--ruby and FIELD are mutually exclusive" if
      field and options[:format] == :ruby

    if local? then
      if File.exist? gem then
        specs << Gem::Format.from_file_by_path(gem).spec rescue nil
      end

      if specs.empty? then
        specs.push(*dep.matching_specs)
      end
    end

    if remote? then
      found = Gem::SpecFetcher.fetcher.fetch dep, true

      if dep.prerelease? or options[:prerelease]
        found += Gem::SpecFetcher.fetcher.fetch dep, false, true, true
      end

      specs.push(*found.map { |spec,| spec })
    end

    if specs.empty? then
      alert_error "Unknown gem '#{gem}'"
      terminate_interaction 1
    end

    unless options[:all] then
      specs = [specs.sort_by { |s| s.version }.last]
    end

    specs.each do |s|
      s = s.send field if field

      say case options[:format]
          when :ruby then s.to_ruby
          when :marshal then Marshal.dump s
          else s.to_yaml
          end

      say "\n"
    end
  end