old_contents: from .base_executor import ScriptExecutor
  
  
  class Executor(ScriptExecutor):
      ext = '.pl'
      name = 'PRO'
      command = 'swipl'
      test_program = '''
      :- set_prolog_flag(verbose,silent).
      :- prompt(_, '').
      :- use_module(library(readutil)).
  
      main:-
          process,
          halt.
  
      process:-
          write('echo: Hello, World!'), nl,
          true.
  
      :- main.
  '''
      fs = ['.*\.(?:pl|pro)', command]
  
      def get_cmdline(self):
          return [self.get_command(), '--goal=main', '-c', self._code]
  
new_contents: from .base_executor import ScriptExecutor
  
  
  class Executor(ScriptExecutor):
      ext = '.pl'
      name = 'PRO'
      command = 'swipl'
      test_program = '''
      :- set_prolog_flag(verbose,silent).
      :- prompt(_, '').
      :- use_module(library(readutil)).
  
      main:-
          process,
          halt.
  
      process:-
          write('echo: Hello, World!'), nl,
          true.
  
      :- main.
  '''
      fs = ['.*\.(?:pl|pro)', '/lib/swipl', command]
  
      def get_cmdline(self):
          return [self.get_command(), '--goal=main', '-c', self._code]
  
subject: Allow /lib/swipl to Prolog; #192