class Gem::Commands::SourcesCommand

def execute
  options[:list] = !(options[:add] ||
                     options[:clear_all] ||
                     options[:remove] ||
                     options[:update])
  if options[:clear_all] then
    path = File.join Gem.user_home, '.gem', 'specs'
    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 source_uri = options[:add] then
    source = Gem::Source.new source_uri
    begin
      if Gem.sources.include? source_uri then
        say "source #{source_uri} already present in the cache"
      else
        source.load_specs :released
        Gem.sources << source
        Gem.configuration.write
        say "#{source_uri} added to sources"
      end
    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
    Gem.sources.each_source do |src|
      src.load_specs :released
      src.load_specs :latest
    end
    say "source cache successfully updated"
  end
  if options[:list] then
    say "*** CURRENT SOURCES ***"
    say
    Gem.sources.each do |src|
      say src
    end
  end
end