diff --git a/c/mapping/mlr_dsl_cst.c b/c/mapping/mlr_dsl_cst.c
index 2113ef49f..d479f08a0 100644
--- a/c/mapping/mlr_dsl_cst.c
+++ b/c/mapping/mlr_dsl_cst.c
@@ -96,6 +96,7 @@ static void             handle_emitp_lashed_to_file(mlr_dsl_cst_statement_t* s,
 static void                      handle_emit_lashed(mlr_dsl_cst_statement_t* s, variables_t* v, cst_outputs_t* o);
 static void              handle_emit_lashed_to_file(mlr_dsl_cst_statement_t* s, variables_t* v, cst_outputs_t* o);
 static void                         handle_emit_all(mlr_dsl_cst_statement_t* s, variables_t* v, cst_outputs_t* o);
+static void                handle_emit_all_to_stdfp(mlr_dsl_cst_statement_t* s, variables_t* v, cst_outputs_t* o);
 static void                 handle_emit_all_to_file(mlr_dsl_cst_statement_t* s, variables_t* v, cst_outputs_t* o);
 static void                             handle_dump(mlr_dsl_cst_statement_t* s, variables_t* v, cst_outputs_t* o);
 static void                     handle_dump_to_file(mlr_dsl_cst_statement_t* s, variables_t* v, cst_outputs_t* o);
@@ -883,7 +884,7 @@ static mlr_dsl_cst_statement_t* alloc_emit(mlr_dsl_ast_node_t* pnode, int type_i
 	if (poutput_node->type == MD_AST_NODE_TYPE_STREAM) {
 		pstatement->pnode_handler = output_all ? handle_emit_all : handle_emit;
 	} else if (pfilename_node->type == MD_AST_NODE_TYPE_STDOUT || pfilename_node->type == MD_AST_NODE_TYPE_STDERR) {
-		pstatement->pnode_handler = handle_emit_to_stdfp;
+		pstatement->pnode_handler = output_all ? handle_emit_all_to_stdfp : handle_emit_to_stdfp;
 		pstatement->stdfp = (pfilename_node->type == MD_AST_NODE_TYPE_STDOUT) ? stdout : stderr;
 	} else {
 		pstatement->poutput_filename_evaluator = rval_evaluator_alloc_from_ast(pfilename_node,
@@ -1983,6 +1984,20 @@ static void handle_emit_to_stdfp(
 	variables_t*             pvars,
 	cst_outputs_t*           pcst_outputs)
 {
+	// xxx handle better, maybe in a class. the opts aren't complete at alloc time so we need to handle them here.
+	if (pnode->psingle_lrec_writer == NULL) {
+		cli_opts_t* popts = MLR_GLOBALS.popts;
+		pnode->psingle_lrec_writer = lrec_writer_alloc(popts->ofile_fmt, popts->ors, popts->ofs, popts->ops,
+			popts->headerless_csv_output, popts->oquoting, popts->left_align_pprint,
+			popts->right_justify_xtab_value, popts->json_flatten_separator, popts->quote_json_values_always,
+			popts->stack_json_output_vertically, popts->wrap_json_output_in_outer_list);
+		if (pnode->psingle_lrec_writer == NULL) {
+			fprintf(stderr, "%s: internal coding error detected in file \"%s\" at line %d.\n",
+				MLR_GLOBALS.bargv0, __FILE__, __LINE__);
+			exit(1);
+		}
+	}
+
 	sllv_t* poutrecs = sllv_alloc();
 	int keys_all_non_null_or_error = TRUE;
 	sllmv_t* pmvkeys = evaluate_list(pnode->pemit_keylist_evaluators, pvars, &keys_all_non_null_or_error);
@@ -2176,6 +2191,44 @@ static void handle_emit_all(
 	sllmv_free(pmvnames);
 }
 
+static void handle_emit_all_to_stdfp(
+	mlr_dsl_cst_statement_t* pnode,
+	variables_t*             pvars,
+	cst_outputs_t*           pcst_outputs)
+{
+	// xxx handle better, maybe in a class. the opts aren't complete at alloc time so we need to handle them here.
+	if (pnode->psingle_lrec_writer == NULL) {
+		cli_opts_t* popts = MLR_GLOBALS.popts;
+		pnode->psingle_lrec_writer = lrec_writer_alloc(popts->ofile_fmt, popts->ors, popts->ofs, popts->ops,
+			popts->headerless_csv_output, popts->oquoting, popts->left_align_pprint,
+			popts->right_justify_xtab_value, popts->json_flatten_separator, popts->quote_json_values_always,
+			popts->stack_json_output_vertically, popts->wrap_json_output_in_outer_list);
+		if (pnode->psingle_lrec_writer == NULL) {
+			fprintf(stderr, "%s: internal coding error detected in file \"%s\" at line %d.\n",
+				MLR_GLOBALS.bargv0, __FILE__, __LINE__);
+			exit(1);
+		}
+	}
+
+	// xxx code-dedupe
+	sllv_t* poutrecs = sllv_alloc();
+	int all_non_null_or_error = TRUE;
+	sllmv_t* pmvnames = evaluate_list(pnode->pemit_oosvar_namelist_evaluators, pvars, &all_non_null_or_error);
+	if (all_non_null_or_error) {
+		mlhmmv_all_to_lrecs(pvars->poosvars, pmvnames, poutrecs,
+			pnode->do_full_prefixing, pcst_outputs->oosvar_flatten_separator);
+	}
+	sllmv_free(pmvnames);
+
+	while (poutrecs->phead != NULL) {
+		lrec_t* poutrec = sllv_pop(poutrecs);
+		pnode->psingle_lrec_writer->pprocess_func(pnode->stdfp, poutrec, pnode->psingle_lrec_writer->pvstate);
+		if (pcst_outputs->flush_every_record)
+			fflush(pnode->stdfp);
+	}
+	sllv_free(poutrecs);
+}
+
 static void handle_emit_all_to_file(
 	mlr_dsl_cst_statement_t* pnode,
 	variables_t*             pvars,