docs: def get_all():
      '''
      Return a list of all available services
  
      CLI Example:
  
      .. code-block:: bash
  
          salt '*' service.get_all
      '''
      if not os.path.isdir(_GRAINMAP.get(__grains__.get('os'), '/etc/init.d')):
          return []
      return sorted(os.listdir(_GRAINMAP.get(__grains__.get('os'), '/etc/init.d')))