Node - The Process Object

A process is the instance of a computer program that is being executed. (-› Activity Monitor)

Node has a global process object with useful methods and information about the current process.

https://nodejs.org/api/process.html

process.env

is an object which stores and controls information about the environment in which the process is currently running.

• contains a PWD property which holds a string with the directory in which the current process is located.

• -› convention is to add a property to process.env with the key NODE_ENV and a value of either production or development.

• if (process.env.NODE_ENV === 'development'){
    console.log('Testing! Testing! Does everything work?');
  }
  

process.memoryUsage()

returns information on the CPU demands of the current process.

similar to this:

{ rss: 26247168,
  heapTotal: 5767168,
  heapUsed: 3573032,
  external: 8772 }

Heap can mean different things in different contexts: a heap can refer to a specific data structure (opens new window), but it can also refer to the a block of computer memory (opens new window).

process.memoryUsage().heapUsed will return a number representing how many bytes of memory the current process is using.

process.argv

holds an array of command line values provided when the current process was initiated.

0. absolute path to Node, which ran the process

1. path to the file that’s running

2. following elements will be any command line arguments provided when the process was initiated

node myProgram.js testing several features

console.log(process.argv[3]); // Prints 'several'

process.argv[2] -› first parameter