code: def do_ls(self, line):
          
          opts = self.LS_OPTS
          line = line.split()
          _pattern = ""
  
          if len(line) == 0:
              # default contextual behaviour [2016-03-01]
              if not self.current:
                  line = ["ontologies"]
              elif self.currentEntity:
                  self.do_info("")
                  return
              else:
                  line = ["classes"]
  
          if (not line) or (line[0] not in opts):
              self.help_ls()
              return
              # self._print("Usage: ls [%s]" % "|".join([x for x in opts]))
  
          elif line[0] == "ontologies":
              if not self.all_ontologies:
                  self._help_nofiles()
              else:
                  self._select_ontology(_pattern)
  
          elif line[0] in opts and not self.current:
              self._help_noontology()
              return
  
          elif line[0] == "classes":
              g = self.current['graph']
  
              if g.all_classes:
                  self._select_class(_pattern)
              else:
                  self._print("No classes available.")
  
          elif line[0] == "properties":
              g = self.current['graph']
              if g.all_properties:
                  self._select_property(_pattern)
              else:
                  self._print("No properties available.")
  
          elif line[0] == "concepts":
              g = self.current['graph']
              if g.all_skos_concepts:
                  self._select_concept(_pattern)
              else:
                  self._print("No concepts available.")
  
          else:  # should never arrive here
              pass
docs: Shows entities of a given kind.