node-red/nodes/storage/28-tail.js

48 lines
1.2 KiB
JavaScript

/**
* Copyright 2013 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.
**/
var RED = require("../../red/red");
var fs = require("fs");
var spawn = require('child_process').spawn;
function TailNode(n) {
RED.nodes.createNode(this,n);
this.filename = n.filename;
this.split = n.split;
var node = this;
var tail = spawn("tail", ["-f", this.filename]);
tail.stdout.on("data", function (data) {
var msg = {topic:node.filename};
if (node.split) {
var strings = data.toString().split("\n");
for (s in strings) {
if (strings[s] != "") {
msg.payload = strings[s];
node.send(msg);
}
}
}
else {
msg.payload = data.toString();
node.send(msg);
}
});
}
RED.nodes.registerType("tail",TailNode);