execute

# File lib/rubygems/commands/specification_command.rb, line 74
  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 v = options[:version]
    when String
      req = Gem::Requirement.create v
    when Gem::Requirement
      req = v
    else
      raise Gem::CommandLineError, "Unsupported version type: '#{v}'"
    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, req
    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::Package.new(gem).spec rescue nil
      end

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

    if remote? then
      dep.prerelease = options[:prerelease]
      found, _ = Gem::SpecFetcher.fetcher.spec_for_dependency dep

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

    if specs.empty? then
      alert_error "No gem matching '#{dep}' found"
      terminate_interaction 1
    end

    unless options[:all] then
      specs = [specs.max_by { |s| s.version }]
    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