--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/streamlet-examples/date	Sat Oct 24 22:59:57 2020 +0200
@@ -0,0 +1,38 @@
+#!/bin/bash
+
+# Relational pipes
+# Copyright © 2020 František Kučera (Frantovo.cz, GlobalCode.info)
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, version 3 of the License.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+
+# This streamlet provides a single attribute: MIME type of given file.
+# It calls the tool file.
+
+
+. "$(dirname "$(realpath "$0")")/streamlet-common.sh"
+
+processMessage_WAITING_FOR_OUTPUT_ATTRIBUTES_METADATA() {
+	send OUTPUT_ATTRIBUTE_METADATA "${outputAttributeAliases[0]-date}"    "string"
+	send WAITING_FOR_INPUT_ATTRIBUTES
+}
+
+processMessage_WAITING_FOR_OUTPUT_ATTRIBUTES() {
+	timestamp=$(stat --format="%Y" "$currentFile");
+	value=$(date --iso-8601=s --date="@$timestamp");
+	send OUTPUT_ATTRIBUTE "$value"    "false";
+	send WAITING_FOR_INPUT_ATTRIBUTES;
+}
+
+initialize
+processMessages