os

---

1. Get Current Working Directory

const os = require('os');

console.log(os.cwd());

2. Get Temporary Directory

const os = require('os');

console.log(os.tmpdir());

3. Get Home Directory

const os = require('os');

console.log(os.homedir());

4. Get Username

const os = require('os');

console.log(os.userInfo().username);

5. Get Platform

const os = require('os');

console.log(os.platform());
// e.g. 'linux', 'darwin', 'win32'

6. Get Architecture

const os = require('os');

console.log(os.arch());
// e.g. 'x64', 'arm'

7. Get Hostname

const os = require('os');

console.log(os.hostname());

8. Get Release

const os = require('os');

console.log(os.release());
// e.g. '10.15.7'

9. Get CPU Information (Physical)

const os = require('os');

console.log(os.cpus());
/*
[
  {
    model: 'Intel(R) Core(TM) i7-1065G7 CPU @ 1.30GHz',
    speed: 1300,
    times: {
      user: 1103000,
      nice: 0,
      sys: 547000,
      idle: 7244000
    }
  },
  // ...
]
*/

10. Get CPU Information (Logical)

const os = require('os');

console.log(os.cpus().length);
// e.g. 4

11. Get Free Memory

const os = require('os');

console.log(os.freemem());
// e.g. 16252236800

12. Get Total Memory

const os = require('os');

console.log(os.totalmem());
// e.g. 33554432000

13. Get Network Interfaces

const os = require('os');

const networkInterfaces = os.networkInterfaces();
for (const key in networkInterfaces) {
  console.log(key, networkInterfaces[key]);
}

14. Restart the System

const os = require('os');

// Note: This requires root privileges.
os.reboot();

15. Shutdown the System

const os = require('os');

// Note: This requires root privileges.
os.shutdown();

16. Get System Uptime

const os = require('os');

console.log(os.uptime());
// e.g. 123456

17. Get Load Average

const os = require('os');

const [oneMinAvg, fiveMinAvg, fifteenMinAvg] = os.loadavg();
console.log(oneMinAvg, fiveMinAvg, fifteenMinAvg);

18. Check If Process Is Running

const os = require('os');

console.log(os.getPriority(process.pid));
// e.g. 0

19. Change Process Priority

const os = require('os');

// Note: This requires root privileges.
os.setPriority(process.pid, 10);

20. Get File System Information

const os = require('os');

console.log(os.stats('/usr/local'));
/*
{
  dev: 16777221,
  mode: 16877,
  nlink: 2,
  uid: 0,
  gid: 0,
  rdev: 0,
  blksize: 4096,
  ino: 18392942,
  size: 4096,
  blocks: 8,
  atimeMs: 1645227746653.946,
  mtimeMs: 1645227746653.946,
  ctimeMs: 1645227746653.946,
  birthtimeMs: 1645227746653.946
}
*/

21. Check File Access

const os = require('os');

console.log(os.access('/usr/local', os.constants.R_OK));
// e.g. true

22. Read File

const os = require('os');

console.log(os.readFileSync('/usr/local/bin/node', 'utf-8'));
// e.g. '#!/usr/bin/env node'

23. Write File

const os = require('os');

os.writeFileSync('/tmp/test.txt', 'Hello, world!', 'utf-8');

24. Rename File

const os = require('os');

os.rename('/tmp/test.txt', '/tmp/new-test.txt');

25. Delete File

const os = require('os');

os.unlink('/tmp/new-test.txt');

26. Create Directory

const os = require('os');

os.mkdir('/tmp/new-directory');

27. Delete Directory

const os = require('os');

os.rmdir('/tmp/new-directory');

28. Change Directory

const os = require('os');

os.chdir('/tmp');

29. List Files in Directory

const os = require('os');

console.log(os.readdirSync('/usr/local/bin'));
// e.g. ['node', 'npm', 'npx', 'tsc']

30. Check If Path Exists

const os = require('os');

console.log(os.pathExists('/usr/local/bin/node'));
// e.g. true

31. Get File Size

const os = require('os');

console.log(os.statSync('/usr/local/bin/node').size);
// e.g. 123456

32. Convert Path to Absolute Path

const os = require('os');

console.log(os.realpathSync('/usr/local/bin/node'));
// e.g. '/usr/local/bin/node'

33. Normalize Path

const os = require('os');

console.log(os.normalize('/usr/local/bin//node'));
// e.g. '/usr/local/bin/node'

34. Resolve Path

const os = require('os');

console.log(os.resolve('/usr/local/bin/node'));
// e.g. '/usr/local/bin/node'

35. Get Temporary File Name

const os = require('os');

console.log(os.tmpDir() + '/file.txt');

36. Create Temporary File

const os = require('os');
const fs = require('fs');

const tmpFile = os.tmpDir() + '/file.txt';
fs.writeFileSync(tmpFile, 'Hello, world!');