A tiny CLI logging library.

A lightweight, worry-free and colourful logging module for console applications which supports logging to STDOUT/STDERR, a JSON-like log file or a plain text file.

Built for intuitive usage and a neat and helpful look in the terminal.

Features

Beautify objects and errors
Print buffers as hex dump
Tagging
Show timestamps and the related source file
Easily debug promises
Simple timing support for messages, functions and promises
Full color support
Log to console (with support for -v/-q arguments) or to a file

const mulog = require("mulog");
mulog.get({file:"log.txt"}) // How to set a file/change other configuration options.
const µ = mulog.get(); // Use mulog as a singleton; recommended.
// const µ = new mulog(); // Use mulog as an object.

// Basic usage
µ("Hello World");
µ.info("This is mulog, a really simple but beautiful logging library.");
µ.error("Something went wrong");
µ.warn("This is your first warning");
µ.success("The action has been completed successfully.");
µ.log("µ.log('...') is the same as µ('...')") // µlog is also chainable
 .verbose("Something less important")
 .debug("Some debug message nobody wants to read");

// Advanced stuff to log
µ("The current year is", new Date().getFullYear());
µ("Use " + require("colors/safe").red("colored text") + " from any library you like, and display beautifully formatted...", {
    "Objects": "like this one!",
    "Some stuff": 5,
    Whatever: true,
    fancy: function() { console.log("Hello World"); }
});
µ.hex("Hell\000\001World"); // hex dump, always printed on debug level

{
    // Tags (recommended syntax for tagging full files/modules)
    const µ = mulog.get().tag("hello world");
    µ.info("Now listening on localhost:8000");

    // Nested tags and chained tag syntax
    µ.tag("requests").verbose("[404] /hello-world.txt");
}

const doSomething = () => {a = 1; for (let i = 0; i < 1000000000000 * Math.random(); i++) { a = a * i; }; return a};
const doPromise = () => new Promise((resolve, reject) => setTimeout(() => Math.random() > 0.5 ? resolve("Success!") : reject(new Error("Alea iacta est")), 600));

// Promises
µ(doPromise());

// Timing (short)
µ.timer().debug(doSomething());

// Timing (as instance)
const t = µ.timer();
t.debug("Something...");
doSomething();
t.debug("...happened!");

Default configuration

const mulog = require("mulog");
const µ = mulog.get({ // Config is only applied on first initialization.
    levels: mulog.styles.DEFAULT,
    console: {
        colors: true,
        utc: true, // local timezone if false
        
        //   1   ->   2  ->    3    ->   4  ->  5  ->    6    ->   7
        // error -> warn -> success -> info -> log -> verbose -> debug
        verbosity: 5,
        respectVerbosityArgs: true, // Respect command line arguments in the format -v/-q/-vvv/-qqq/...
        
        wrap: true,
        hardWrap: false,
        indent: true
    },
    file: { // Text file output
        path: null, //"logfile.txt",
        verbosity: 100
    },
    logfile: { // JSON file output
        path: null, //"logfile.json",
        verbosity: 100
    },
    eyes: { /* Configuration for https://npmjs.com/package/eyes */ }
});

Available styles

Roadmap

CLI to view JSON log files, with filtering
proxy to different logging framework if used in a module (e.g. global.µ = mulog.proxy("winston", winston), maybe even with autodetection if possible (?))
~~syslog integration~~ (this needs to be done by the process manager, e.g. Docker or SystemD)

moqmar/mulog

A tiny CLI logging library.

Features

Default configuration

Available styles

Roadmap