Crude file monitor example

monitor.js

var express = require('express');
var clc = require('cli-color');
var fs = require('fs');
var EventEmitter = require('events').EventEmitter;
var util = require('util')

var http = require('http').Server(app);
var io = require('socket.io')(http);
 
var app = express();
app.use(express.static(__dirname + '/css'));
app.get('/', function(req, res){
  res.sendfile('index.html');
});

var FileMonitor = function( path ) {
  EventEmitter.call(this);
  var fileMonitor = this;

  fileMonitor.path          = path;
  fileMonitor.lastStat      = fs.statSync( path );
  fileMonitor.lastStringLen = 0;

  setInterval(function(){
    fs.stat( path, function( err, stat ) {
      if (err) fileMonitor.emit('error', err);
      if (stat.mtime.getTime() !== fileMonitor.lastStat.mtime.getTime()) {
        fileMonitor.lastStat = stat;
        fs.readFile( path, function( err, data ) {
          if (err) fileMonitor.emit('error', err);

          data += '';

          if (fileMonitor.lastStringLen < data.length) {
            fileMonitor.emit('change', data.substring( fileMonitor.lastStringLen ));
          } 
          else {
            fileMonitor.emit('change', 'something was deleted!');
          }

          fileMonitor.lastStringLen = data.length;
        })
      }
    })
  },200);

}
util.inherits( FileMonitor, EventEmitter );

  io.on('connection', function(socket){
 
      var client = socket.handshake.address;
      console.log(clc.green('<') + ' Accepted connection from ' + clc.bold(client))
 
      socket.on('disconnect', function() {
         console.log(clc.green('>') + ' Recieved disconnect from ' + clc.bold(client))
      });

  });

var fileMon = new FileMonitor( 'test.log' );
fileMon.on( 'change', function(data) {
  io.emit('log_msg', data);
})
 
http.listen(8080, function(){
    console.log(clc.cyan.bold('Server running on port 8080'));
});