os

The os module is another built-in Node.js module that gives you information about the system where your Node process is running. Super handy for logging, monitoring, or system-aware apps 🚀.

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📂 1. Importing

const os = require("os");

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🛠️ 2. Common Methods & Properties

System Info

console.log(os.type());       // 'Linux', 'Darwin' (macOS), 'Windows_NT'
console.log(os.platform());   // 'linux', 'darwin', 'win32'
console.log(os.arch());       // 'x64', 'arm64'
console.log(os.release());    // OS version

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CPU Info

console.log(os.cpus());
// Array of objects describing each logical CPU core
console.log(os.cpus().length); // number of cores

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Memory Info

console.log(os.totalmem()); // Total system memory (bytes)
console.log(os.freemem());  // Free system memory (bytes)

👉 Often wrapped with (value / 1024 / 1024 / 1024).toFixed(2) to display in GB.

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User & Host Info

console.log(os.userInfo());
// { uid: 501, username: 'tyson', homedir: '/Users/tyson', shell: '/bin/zsh' }
 
console.log(os.hostname()); // Machine name

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Network Info

console.log(os.networkInterfaces());
// { eth0: [ { address, family, mac, internal, ... } ], ... }

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Paths

console.log(os.homedir());  // Home directory path
console.log(os.tmpdir());   // Temp directory path

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System Uptime

console.log(os.uptime()); // Seconds since system boot

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✅ In Short

The os module helps you query:

• System details → type, platform, arch, release

• CPU & memory → cpus(), totalmem(), freemem()

• User info → userInfo(), homedir()

• Network info → networkInterfaces()

• Uptime → how long system has been running

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👉 Want me to show you a practical example — like building a small Node.js script that logs system stats (CPU usage %, free memory, uptime) in a clean format — or should we continue straight to the http module (servers) next?