docs: def do_update(config, config_dir):
      """
      CLI action "update new configuration".
      """
      if not os.path.exists(config_dir):
          print "Configuration '{}' does not exist.".format(config)
          exit(1)
  
      config_file = os.path.join(config_dir, 'config')
      with open(config_file, 'r') as f:
          old_config_data = json.load(f)
  
      old_url = old_config_data['url']
      old_torrent_dir = old_config_data['torrent_dir']
      old_update_interval = old_config_data['update_interval']
  
      url = raw_input("RSS URL for processing [{}]: "\
          .format(old_url)) or old_url
      torrent_dir = raw_input("Output directory for found .torrent files [{}]: "\
          .format(old_torrent_dir)) or old_torrent_dir
      update_interval = raw_input("Update interval (mins) [{}]: "\
          .format(old_update_interval)) or old_update_interval
  
      editor = os.environ["EDITOR"]
  
      config_filter = os.path.join(config_dir, 'filter')
      if confirm("Do you want to edit filters list?", False):
          call([editor, config_filter])
          print "Filter configuration has been saved."
  
      config_blacklist = os.path.join(config_dir, 'blacklist')
      if confirm("Do you want to edit blacklist?", False):
          call([editor, config_filter])
          print "Blacklist configuration has been saved."
  
      config_data = json.dumps({
          "url": url,
          "torrent_dir": torrent_dir,
          "update_interval": update_interval
      }, sort_keys=True, indent=4, separators=(',', ': '))
      with open(config_file, 'w') as f:
          f.write(config_data)
  
      ct = CronTab(user=True)
      for job in ct:
          if re.match('.*ghetto.*\-e\s{}'.format(config), job.command):
              ct.remove(job)
  
      cmd = "{} {} -e {}".format(sys.executable,
                                 os.path.abspath(__file__),
                                 config)
      new_job = ct.new(command=cmd)
      new_job.minute.every(update_interval)
      new_job.enable()
      ct.write()
      print "Crontab updated."
  
      print "Configuration '{}' has been updated.".format(config)