Where is nodejs log file

Question

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

User · Accepted Answer

There is no log file  Each node js  app  is a separate entity  By default it will log errors to STDERR and output to STDOUT  You can change that when you run it from your shell to log to a file instead   node my app js  gt  my app log log 2 gt  my app err log   Alternatively  recommended   you can add logging inside your application either manually or with one of the many log libraries    winston log4js

User · Answer

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   and      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   amp  -e    ex  forever start -l forever log -o out log -e err log my-daemon js   forever stop my-daemon js

User · Answer

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

User · Answer

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        logger info 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

[node.js] Where is nodejs log file?

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