Node.js - read child process stdout to variable

In this short article, we would like to show how to receive child process output in JavaScript script run under Node JS.

child_script.js file:

console.log('Child script...');

main_script.js file:

const { execSync } = require('child_process');

console.log('Main script...');

const result = execSync('node child_script.js');
console.log(result.toString());

Usage example (run in the console):

$ node main_script.js 
Main script...
Child script...

Notes:

• pay attention we run node process under node process what is not the best practice but sometimes it is necessary,
• by using toString() on result variable we wait until all data is recived from child process (node child_script.js),
• node child_script.js can be replaced by any command, e.g. ls -al /