30 Days of node
Day 26 : OS Module in node.js



30 days of node - Nodejs tutorial series

  1. Day 1 - The Beginning
  2. Day 2 - File System in node.js
  3. Day 3 - Regular expressions in node.js
  4. Day 4 - Console module in node.js
  5. Day 5 - All about errors
  6. Day 6 - Array methods
  7. Day 7 - All about NPM
  8. Day 8 - Publishing package on NPM
  9. Day 9 - Crypto Module ( Hashing and HMAC)
  10. Day 10 - Crypto Module ( Encryption and Decryption )
  11. Day 11 - Express Framework
  12. Day 12 - CRUD in MongoDB using node.js
  13. Day 13 - Sign Up form in node.js
  14. Day 14 - Introduction to socket.io
  15. Day 15 - All about streams
  16. Day 16 - Zlib Module
  17. Day 17 - CRUD in MySQL using node.js
  18. Day 18 - Concepts of callbacks in node.js
  19. Day 19 - Query String in node.js
  20. Day 20 - Timers in node.js
  21. Day 21 - Buffers in node.js
  22. Day 22 - String Decoder Module in node.js
  23. Day 23 - Debugger module in node.js
  24. Day 24 - Child Processes in node.js
  25. Day 25 - Clusters in node.js
  26. Day 26 - OS module in node.js
  27. Day 27 - Assert module in node.js
  28. Day 28 - Getting Tweets using node.js
  29. Day 29 - Uploading file to dropbox using node.js
  30. Day 30 - Github API with node.js

Introduction

OS module in node.js is used to provide utilities related to operating system. It can be accessed using the following : 

								
var os = require('os');

os.cpus()

This method is used to get the information of all the CPU/Core installed in the system. This method returns an array . Code snippet is given below : 

								
//Name of the file : cpus.js
var os = require('os');
var value =  os.cpus();
console.log("os.cpus() ==> " + JSON.stringify(value) );

We can run it in the following way : 
								
>node cpus.js
os.cpus() ==> [{"model":"Intel(R) Core(TM) i3-2348M CPU @ 2.30GHz","speed":2294,
"times":{"user":3067572,"nice":0,"sys":1015862,"idle":12850535,"irq":149667}},{"
model":"Intel(R) Core(TM) i3-2348M CPU @ 2.30GHz","speed":2294,"times":{"user":5
95611,"nice":0,"sys":169822,"idle":16167943,"irq":4664}},{"model":"Intel(R) Core
(TM) i3-2348M CPU @ 2.30GHz","speed":2294,"times":{"user":3278049,"nice":0,"sys"
:813467,"idle":12841783,"irq":13572}},{"model":"Intel(R) Core(TM) i3-2348M CPU @
 2.30GHz","speed":2294,"times":{"user":319786,"nice":0,"sys":80215,"idle":165331
57,"irq":967}}]

Note that In the above Output the value of nice is 0 because nice values are unix specified and our outputs are as per windows operating system.

os.arch()

This method is used to return the CPU architecture of operating system for which the node.js binary was compiled.
Possible values are : 'arm', 'arm64', 'ia32', 'mips', 'mipsel', 'ppc', 'ppc64', 's390', 's390x', 'x32', 'x64', and 'x86'. This method returns String . Code snippet is given below : 

								
//Name of the file: arch.js
var os = require('os');
var value =  os.arch();
console.log("os.arch() ==> " + value);

We can run it in the following way : 
								
>node arch.js
os.arch() ==> ia32

os.endianness()

This method is used to get the endianness of the CPU for which the node.js binary was compiled.
Possible values are :

  • 'BE' : for big endian
  • 'LE' : for little endian
This method returns String . Code snippet is given below : 
								
//Name of the file: endianness.js
var os = require('os');
var value =  os.endianness();
console.log("os.endianness() => " + value);

We can run it in the following way : 
								
>node endianness.js
os.endianness() => LE

os.freemem()

This method is used to get the amount of free system memory in bytes. This method returns Integer . Code snippet is given below : 

								
//Name of the file: freemem.js
var os = require('os');
var value =  os.freemem();
console.log("os.freemem() => " + value);

We can run it in the following way : 
								
>node freemem.js
os.freemem() => 690982912

os.hostname()

This method is used to get the hostname of the operating system. This method returns String . Code snippet is given below : 

								
//Name of the file: hostname.js
var os = require('os');
var value =  os.hostname();
console.log("os.hostname() => " + value);

We can run it in the following way : 
								
>node hostname.js
os.hostname() => acer-PC

os.homedir()

This method is used to get the home directory of the current user. This method returns String . Code snippet is given below : 

								
//Name of the file: homedir.js
var os = require('os');
var value =  os.homedir();
console.log("os.homedir() => " + value);

We can run it in the following way : 
								
>node homedir.js
os.homedir() => C:\Users\acer

os.platform()

This method is used to get the operating system platform as set during compile time of node.js .
Possible values are :

  • 'win32'
  • 'aix'
  • 'freebsd'
  • 'linux'
  • 'openbsd'
  • 'darwin'
  • 'sunos'
This method returns String . Code snippet is given below : 
								
//Name of the file: platform.js
var os = require('os');
var value =  os.platform();
console.log("os.platform() => " + value);

We can run it in the following way : 
								
>node platform.js
os.platform() => win32

Note that the output of the above code will identify operating system platform as set during compile time of node.js .

os.release()

This method is used to get the operating system release.
This method returns String . Code snippet is given below : 

								
//Name of the file: release.js
var os = require('os');
var value =  os.release();
console.log("os.release() => " + value);

We can run it in the following way : 
								
>node release.js
os.release() => 6.1.7600

os.tmpdir()

This method is used to get the default directory for temporary files in operating system.
This method returns String . Code snippet is given below : 

								
//Name of the file: tmpdir.js
var os = require('os');
var value =  os.tmpdir();
console.log("os.tmpdir() => " + value);

We can run it in the following way : 
								
>node tmpdir.js
os.tmpdir() => C:\Users\acer\AppData\Local\Temp

os.totalmem()

This method is used to get the total amount of system memory in bytes.
This method returns Integer . Code snippet is given below : 

								
//Name of the file: totalmem.js
var os = require('os');
var value =  os.totalmem();
console.log("os.totalmem() => " + value);

We can run it in the following way : 
								
>node totalmem.js
os.totalmem() => 1948631040

os.uptime()

This method is used to get the system uptime in seconds.
This method returns Integer . Code snippet is given below : 

								
//Name of the file: uptime.js
var os = require('os');
var value =  os.uptime();
console.log("os.uptime() => " + value);

We can run it in the following way : 
								
>node uptime.js
os.uptime() => 22906.6507529

os.type()

This method is used to get the operating system name as returned by Uname.
Common values are :

  • 'Windows_NT' : on Windows
  • 'Linux' : on Linux
  • 'debian' : on MacOS
This method returns String . Code snippet is given below : 
								
//Name of the file: type.js
var os = require('os');
var value =  os.type();
console.log("os.type() => " + value);

We can run it in the following way : 
								
>node type.js
os.type() => Windows_NT

Summary

In this chapter of 30 days of node tutorial series, we learned about os module in node.js which is used to provide utilities related to operating system. We learned about following methods : os.cpus() , os.arch() , os.endianness() , os.freemem() , os.hostname() , os.homedir() , os.platform() , os.release() , os.tmpdir() , os.totalmem() , os.uptime() , os.type() , along with their code snippets .