code: def main(argv=None):
      
      arguments = cli_common(__doc__, argv=argv)
      campaign_file = arguments['CAMPAIGN_FILE']
      if arguments['-g']:
          if osp.exists(campaign_file):
              raise Exception('Campaign file already exists')
          with open(campaign_file, 'w') as ostr:
              Generator().write(ostr)
      else:
          node = arguments.get('-n')
          output_dir = arguments.get('--output-dir')
          exclude_nodes = arguments.get('--exclude-nodes')
          srun_tag = arguments.get('--srun')
          driver = CampaignDriver(
              campaign_file,
              node=node,
              output_dir=output_dir,
              srun=srun_tag,
              exclude_nodes=exclude_nodes,
          )
          driver()
          if argv is not None:
              return driver
          campaign_fd = int(arguments.get('--campaign-path-fd') or 1)
          message = (osp.abspath(driver.campaign_path) + '\n').encode()
          os.write(campaign_fd, message)
docs: ben-sh entry point