What is Node.js Process ?

Node.js provides the facility to get process information such as process id, architecture, platform, version, release, uptime, upu usage etc. It can also be used to kill process, set uid, set groups, unmask etc.

The process is a global object, an instance of EventEmitter, can be accessed from anywhere.

Node.js Process Properties

A list of commonly used Node.js process properties are given below.

Property	Description
arch	returns process architecture: 'arm', 'ia32', or 'x64'
args	returns commands line arguments as an array
env	returns user environment
pid	returns process id of the process
platform	returns platform of the process: 'darwin', 'freebsd', 'linux', 'sunos' or 'win32'
release	returns the metadata for the current node release
version	returns the node version
versions	returns the node version and its dependencies

Node.js Process Properties Example

Let's see the simple process example to print architecture, pid, platform and version of the process.

File: process_example1.js

1. console.log(`Process Architecture: ${process.arch}`);  
2. console.log(`Process PID: ${process.pid}`);  
3. console.log(`Process Platform: ${process.platform}`);  
4. console.log(`Process Version: ${process.version}`);  

Open Node.js command prompt and run the following code:

1. node process_example1.js  

Let's see another process example to print command line arguments. Here node is considered as the first argument, filename is considered as the second argument and actual command line arguments are considered as third, fourth, fifth and so on.

File: process_example2.js

1. process.argv.forEach((value, index, array) => {  
2.   console.log(`${index}: ${value}`);  
3. });  

Open Node.js command prompt and run the following code:

1. node process_example2.js  

Node.js Process Functions

A list of commonly used Node.js process functions are given below.

Function	Description
cwd()	returns path of current working directory
hrtime()	returns the current high-resolution real time in a [seconds, nanoseconds] array
memoryUsage()	returns an object having information of memory usage.
process.kill(pid[, signal])	is used to kill the given pid.
uptime()	returns the Node.js process uptime in seconds.

Node.js Process Functions Example

Let's see the process example to print current working directory and uptime of the process.

File: process_example3.js

1. console.log(`Current directory: ${process.cwd()}`);  
2. console.log(`Uptime: ${process.uptime()}`);  

Open Node.js command prompt and run the following code:

1. node process_example3.js