+ leftover = poptGetArg(pc);
+ if (leftover) {
+ ERR("Unknown argument: %s", leftover);
+ ret = CMD_ERROR;
+ goto end;
+ }
+
+ /* Mi check */
+ if (lttng_opt_mi) {
+ writer = mi_lttng_writer_create(fileno(stdout), lttng_opt_mi);
+ if (!writer) {
+ ret = -LTTNG_ERR_NOMEM;
+ goto end;
+ }
+
+ /* Open command element */
+ ret = mi_lttng_writer_command_open(writer,
+ mi_lttng_element_command_start);
+ if (ret) {
+ ret = CMD_ERROR;
+ goto end;
+ }
+
+ /* Open output element */
+ ret = mi_lttng_writer_open_element(writer,
+ mi_lttng_element_command_output);
+ if (ret) {
+ ret = CMD_ERROR;
+ goto end;
+ }
+
+ /*
+ * Open sessions element
+ * For validation purpose
+ */
+ ret = mi_lttng_writer_open_element(writer,
+ config_element_sessions);
+ if (ret) {
+ ret = CMD_ERROR;
+ goto end;
+ }
+ }
+
+ command_ret = start_tracing();
+ if (command_ret) {
+ success = 0;
+ }
+
+ /* Mi closing */
+ if (lttng_opt_mi) {
+ /* Close sessions and output element */
+ ret = mi_lttng_close_multi_element(writer, 2);
+ if (ret) {
+ ret = CMD_ERROR;
+ goto end;
+ }
+
+ /* Success ? */
+ ret = mi_lttng_writer_write_element_bool(writer,
+ mi_lttng_element_command_success, success);
+ if (ret) {
+ ret = CMD_ERROR;
+ goto end;
+ }
+
+ /* Command element close */
+ ret = mi_lttng_writer_command_close(writer);
+ if (ret) {
+ ret = CMD_ERROR;
+ goto end;
+ }
+ }