[CCSDK-28] populated the seed code for dgbuilder

[ccsdk/distribution.git] / dgbuilder / core_nodes / storage / 28-tail.js

diff --git a/dgbuilder/core_nodes/storage/28-tail.js b/dgbuilder/core_nodes/storage/28-tail.js
new file mode 100644 (file)
index 0000000..89c7a63
--- /dev/null
+++ b/dgbuilder/core_nodes/storage/28-tail.js
@@ -0,0 +1,69 @@
+/**
+ * Copyright 2013, 2014 IBM Corp.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ **/
+
+module.exports = function(RED) {
+    "use strict";
+    var spawn = require('child_process').spawn;
+    var plat = require('os').platform();
+
+    if (plat.match(/^win/)) {
+        throw "Info : Currently not supported on Windows.";
+    }
+
+    function TailNode(n) {
+        RED.nodes.createNode(this,n);
+
+        this.filename = n.filename;
+        this.split = n.split;
+        var node = this;
+
+        var err = "";
+        // TODO: rewrite to use node-tail
+        var tail = spawn("tail", ["-F", "-n", "0", this.filename]);
+        tail.stdout.on("data", function (data) {
+            if (node.split) {
+                // TODO: allow customisation of the line break - as we do elsewhere
+                var strings = data.toString().split("\n");
+                for (var s in strings) {
+                    //TODO: should we really filter blanks? Is that expected?
+                    if (strings[s] !== "") {
+                        node.send({
+                            topic: node.filename,
+                            payload: strings[s]
+                        });
+                    }
+                }
+            }
+            else {
+                var msg = {
+                    topic:node.filename,
+                    payload: data.toString()
+                };
+                node.send(msg);
+            }
+        });
+
+        tail.stderr.on("data", function(data) {
+            node.warn(data.toString());
+        });
+
+        this.on("close", function() {
+            if (tail) { tail.kill(); }
+        });
+    }
+
+    RED.nodes.registerType("tail",TailNode);
+}