os

The os module provides operating system-related utility methods and properties. Useful for system information and environment-aware programs.

API Surface

System Information

  • os.platform() — operating system platform (linux, win32, darwin).
  • os.arch() — CPU architecture (x64, arm64).
  • os.version() — OS version string.
  • os.release() — OS release.
  • os.type() — OS name (Linux, Windows_NT, Darwin).

Resources

  • os.cpus() — info about each CPU core.
  • os.totalmem(), os.freemem() — total and free memory in bytes.
  • os.loadavg() — load averages (Unix only).
  • os.uptime() — system uptime in seconds.

User & Paths

  • os.userInfo() — current user details.
  • os.homedir() — home directory path.
  • os.tmpdir() — temp directory path.
  • os.hostname() — system hostname.

Network

  • os.networkInterfaces() — object with network details.

Constants

  • os.constants — error codes, signals, etc.

Examples (English only)

const os = require("os");

console.log("Platform:", os.platform());
console.log("Arch:", os.arch());
console.log("Hostname:", os.hostname());

console.log("CPUs:", os.cpus().length);
console.log("Total mem:", os.totalmem());
console.log("Free mem:", os.freemem());

console.log("Home dir:", os.homedir());
console.log("Temp dir:", os.tmpdir());

console.log("Network:", os.networkInterfaces());

Notes

  • Values like memory are in bytes — convert for readability.
  • loadavg is Unix-only, returns [1m, 5m, 15m] load averages.
  • Use os.constants for error/signal codes instead of hardcoding.
  • System info may differ across platforms — always test cross-platform.