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I can't find a place where nodejs log file is stored. Because in my node server I have "Segmentation fault", I want to look at log file for additional info...

Node.js Logging Tutorial, Log file. You can redirect stdout and stderr to a file and not have to touch your code if you've already used console everywhere. You  Learn how you can take your Node.js logging in your library, application or CLI from "console.log" to the next level using libraries like "pino" or "debug". A Guide to Node.js Logging - Twilio Level up your Twilio API skills in TwilioQuest , an educational game for Mac, Windows, and Linux.

forever might be of interest to you. It will run your .js-File 24/7 with logging options. Here are two snippets from the help text:

[Long Running Process] The forever process will continue to run outputting log messages to the console. ex. forever -o out.log -e err.log my-script.js


[Daemon] The forever process will run as a daemon which will make the target process start in the background. This is extremely useful for remote starting simple node.js scripts without using nohup. It is recommended to run start with -o -l, & -e. ex. forever start -l forever.log -o out.log -e err.log my-daemon.js forever stop my-daemon.js

A Guide to Node.js Logging, When you write the following code in Node.js in a file called index.js : console.log​('Hello there'); console.error('Bye bye');. And execute it in the  Node.js logging. There are so many ways to log in Node.js. We can use what’s built in, or rely on one of the many popular packages to improve logging. As of today, the ideal way to accomplish logging is to pipe the stdout and stderr to your preferred log destination.

If you use docker in your dev you can do this in another shell: docker attach running_node_app_container_name

That will show you STDOUT and STDERR.

How to Get Node.js Logging Right, A logical extension to this simple example would be to log to a file. After all, we want to be able to read the logs in cases where we don't have  node script-file.js > log-file.txt This tells the shell to write the standard output of the command node script-file.js to your log file instead of the default, which is printing it to the console. This is called redirection and its very powerful. Say you wanted to write all errors to a separate file

For nodejs log file you can use winston and morgan and in place of your console.log() statement user winston.log() or other winston methods to log. For working with winston and morgan you need to install them using npm. Example: npm i -S winston npm i -S morgan

Then create a folder in your project with name winston and then create a config.js in that folder and copy this code given below.

const appRoot = require('app-root-path');
const winston = require('winston');

// define the custom settings for each transport (file, console)
const options = {
  file: {
    level: 'info',
    filename: `${appRoot}/logs/app.log`,
    handleExceptions: true,
    json: true,
    maxsize: 5242880, // 5MB
    maxFiles: 5,
    colorize: false,
  console: {
    level: 'debug',
    handleExceptions: true,
    json: false,
    colorize: true,

// instantiate a new Winston Logger with the settings defined above
let logger;
if (process.env.logging === 'off') {
  logger = winston.createLogger({
    transports: [
      new winston.transports.File(options.file),
    exitOnError: false, // do not exit on handled exceptions
} else {
  logger = winston.createLogger({
    transports: [
      new winston.transports.File(options.file),
      new winston.transports.Console(options.console),
    exitOnError: false, // do not exit on handled exceptions

// create a stream object with a 'write' function that will be used by `morgan`
logger.stream = {
  write(message) {

module.exports = logger;

After copying the above code make make a folder with name logs parallel to winston or wherever you want and create a file app.log in that logs folder. Go back to config.js and set the path in the 5th line "filename: ${appRoot}/logs/app.log, " to the respective app.log created by you.

After this go to your index.js and include the following code in it.

const morgan = require('morgan');
const winston = require('./winston/config');
const express = require('express');
const app = express();
app.use(morgan('combined', { stream: winston.stream }));

winston.info('You have successfully started working with winston and morgan');

Getting Started Quickly With Node.js Logging, A node console and file logger suitable for small, medium and large production projects. NodeJS write log file (Json) Ask Question Browse other questions tagged json node.js logging or ask your own question. The Overflow Blog Introducing Collections

simple-node-logger, Log text to file (with timestamp). Installation. npm install log-to-file --save  I just went through setting up logging using papertrail for a nodejs app.. i started off using winston to send express accesses through to paper trail, but then I ended up just setting express to use process.stdout and using tee to pipe to a file and logger syslog utility so I could have stdout, stderr stored locally as well as aggregated to papertrail, i found it to be a simpler setup but

log-to-file, Winston is the most popular logging library available for Node.js. Winston decouples The code below is all that's required to log to file in Winston. I'll describe  tail -f logfile.txt outputs the last 10 lines of logfile.txt, and then continues to output appended data as the file grows. What's the recommended way of doing the -f part in node.js? The following

Node Logging Basics - The Ultimate Guide To Logging, Next, here's a basic logging example: In this example, we've initialized a Winston object; added a file transport, which will store logs in somefile. file = (string) filepath of the file to read. data = (string or buffer) the data you want to write to the file. encoding = (optional string) the encoding of the data. Possible encodings are 'ascii', 'utf8', and 'base64'. If no encoding provided, then 'utf8' is assumed.