1 files changed, 79 insertions, 0 deletions
diff --git a/erts/example/pg_encode.c b/erts/example/pg_encode.c
new file mode 100644
index 0000000000..34ca1fe46c
--- /dev/null
+++ b/erts/example/pg_encode.c
@@ -0,0 +1,79 @@
+/*
+ * %CopyrightBegin%
+ * 
+ * Copyright Ericsson AB 2006-2009. All Rights Reserved.
+ * 
+ * The contents of this file are subject to the Erlang Public License,
+ * Version 1.1, (the "License"); you may not use this file except in
+ * compliance with the License. You should have received a copy of the
+ * Erlang Public License along with this software. If not, it can be
+ * retrieved online at http://www.erlang.org/.
+ * 
+ * Software distributed under the License is distributed on an "AS IS"
+ * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
+ * the License for the specific language governing rights and limitations
+ * under the License.
+ * 
+ * %CopyrightEnd%
+ */
+#include <erl_driver.h>
+
+#include <libpq-fe.h>
+
+#include <ei.h>
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+
+#include "pg_encode.h"
+
+void encode_ok(ei_x_buff* x)
+{
+    const char* k_ok = "ok";
+    ei_x_encode_atom(x, k_ok);
+}
+
+void encode_error(ei_x_buff* x, PGconn* conn)
+{
+    const char* k_error = "error";
+    ei_x_encode_tuple_header(x, 2);
+    ei_x_encode_atom(x, k_error);
+    ei_x_encode_string(x, PQerrorMessage(conn));
+}
+
+void encode_result(ei_x_buff* x, PGresult* res, PGconn* conn)
+{
+    int row, n_rows, col, n_cols;
+    switch (PQresultStatus(res)) {
+    case PGRES_TUPLES_OK: 
+	n_rows = PQntuples(res); 
+	n_cols = PQnfields(res); 
+	ei_x_encode_tuple_header(x, 2);
+	encode_ok(x);
+	ei_x_encode_list_header(x, n_rows+1);
+ 	ei_x_encode_list_header(x, n_cols);
+	for (col = 0; col < n_cols; ++col) {
+	    ei_x_encode_string(x, PQfname(res, col));
+	}
+	ei_x_encode_empty_list(x); 
+	for (row = 0; row < n_rows; ++row) {
+	    ei_x_encode_list_header(x, n_cols);
+	    for (col = 0; col < n_cols; ++col) {
+		ei_x_encode_string(x, PQgetvalue(res, row, col));
+	    }
+	    ei_x_encode_empty_list(x);
+	}
+	ei_x_encode_empty_list(x); 
+	break; 
+    case PGRES_COMMAND_OK:
+	ei_x_encode_tuple_header(x, 2);
+        encode_ok(x);
+	ei_x_encode_string(x, PQcmdTuples(res));
+        break;
+    default:
+	encode_error(x, conn);
+	break;
+    }
+}
+