unknown option -- -
usage: sftp [-46AaCfNpqrv] [-B buffer_size] [-b batchfile] [-c cipher]
          [-D sftp_server_command] [-F ssh_config] [-i identity_file]
          [-J destination] [-l limit] [-o ssh_option] [-P port]
          [-R num_requests] [-S program] [-s subsystem | sftp_server]
          [-X sftp_option] destination