Logging stdout and stderr of Node

Question

I am using the boilerplate code of mean.io and starting my server with the command:

node server.js

How do I log stdout and stderr of my Express application?

Here's my file server.js :

'use strict';

/**
 * Module dependencies.
 */
var mongoose = require('mongoose'),
    passport = require('passport'),
    logger = require('mean-logger');

/**
 * Main application entry file.
 * Please note that the order of loading is important.
 */

// Initializing system variables
var config = require('./server/config/config');
var db = mongoose.connect(config.db);

// Bootstrap Models, Dependencies, Routes and the app as an express app
var app = require('./server/config/system/bootstrap')(passport, db);

// Start the app by listening on <port>, optional hostname
app.listen(config.port, config.hostname);
console.log('Mean app started on port ' + config.port + ' (' + process.env.NODE_ENV + ')');

// Initializing logger
logger.init(app, passport, mongoose);

// Expose app
exports = module.exports = app;

Answer 1

What about this?

console.log("I will goto the STDOUT");
console.error("I will goto the STDERR");

Note: both of these functions automatically add new line to your input.

If you don't want those newlines appended to your input, do this

process.stdout.write("I will goto the STDOUT")
process.stderr.write("I will goto the STDERR")

Both process.stdout and process.stderr are streams, so you can even pipe a stream into them. See Node.js docs on streams for more info.

Answer 2

You can do this by writing to stdout and stderr streams

process.stdout.write('Hello')

or

process.stderr.write('Error')

Better will be to use some thirdparty logging module like winston or bunyan

Answer 3

The only way I can think of to do this is to spawn a child process (like the fork system call), which then you can "pipe" the output of stderr , stdout to files.

var out = fs.openSync('./output.log', 'a')
  , err = fs.openSync('./error.log', 'a');

require('child_process').spawn('./server', [], {
    detached    : true,
    stdio       : ['ignore', out, err]
});