execute

# File lib/rubygems/commands/sources_command.rb, line 44
  def execute
    options[:list] = !(options[:add] ||
                       options[:clear_all] ||
                       options[:remove] ||
                       options[:update])

    if options[:clear_all] then
      path = Gem::SpecFetcher.fetcher.dir
      FileUtils.rm_rf path

      unless File.exist? path then
        say "*** Removed specs cache ***"
      else
        unless File.writable? path then
          say "*** Unable to remove source cache (write protected) ***"
        else
          say "*** Unable to remove source cache ***"
        end

        terminate_interaction 1
      end
    end

    if options[:add] then
      source_uri = options[:add]
      uri = URI.parse source_uri

      begin
        Gem::SpecFetcher.fetcher.load_specs uri, 'specs'
        Gem.sources << source_uri
        Gem.configuration.write

        say "#{source_uri} added to sources"
      rescue URI::Error, ArgumentError
        say "#{source_uri} is not a URI"
        terminate_interaction 1
      rescue Gem::RemoteFetcher::FetchError => e
        say "Error fetching #{source_uri}:\n\t#{e.message}"
        terminate_interaction 1
      end
    end

    if options[:remove] then
      source_uri = options[:remove]

      unless Gem.sources.include? source_uri then
        say "source #{source_uri} not present in cache"
      else
        Gem.sources.delete source_uri
        Gem.configuration.write

        say "#{source_uri} removed from sources"
      end
    end

    if options[:update] then
      fetcher = Gem::SpecFetcher.fetcher

      Gem.sources.each do |update_uri|
        update_uri = URI.parse update_uri
        fetcher.load_specs update_uri, 'specs'
        fetcher.load_specs update_uri, 'latest_specs'
      end

      say "source cache successfully updated"
    end

    if options[:list] then
      say "*** CURRENT SOURCES ***"
      say

      Gem.sources.each do |source|
        say source
      end
    end
  end