new_contents: #!/usr/bin/env python3
  
  import argparse
  import cmd
  
  
  class Shell(cmd.Cmd):
      intro = 'Welcome to interactive ZFS SnapManage shell.\n' \
              'Type help or ? for list commands.\n'
      prompt = '(SnapManage) '
  
      def do_snapshot(self, arg):
          pass
  
      def do_rollback(self, arg):
          pass
  
      def do_list(self, arg):
          pass
  
      def do_EOF(self, arg):
          print()
          return True
  
  parser = argparse.ArgumentParser()
  
  parser.add_argument('-s', '--dataset',
                      help='Dataset to be operated on', required=True)
  parser.add_argument('-c', '--command',
                      help='Command to be executed, starts interactive shell if ommited')
  
  args = parser.parse_args()
  dataset = args.dataset
  
  if args.command is not None:
      Shell().onecmd(args.command)
  else:
      Shell().cmdloop()
  
subject: Add basic argument parsing, add basic shell functionality