How to append values to the PATH environment variable in NodeJS?

Question

Following the answer suggested in the question -

Is it possible to permanently set environment variables?

I was able to set new environment variables permanently with the command -

spawnSync('setx', ['-m', 'MyDownloads', 'H:\\temp\\downloads'])

But now my goal is to append new values to the PATH environment variable.

Is it possible?

Attrahent

This seems like a question about Windows and the Setx command, not Node, JavaScript, or Electron. – Hiatus

You are right! Ill fix it – Attrahent

Are you try to use my answer? – Viperous

I didn't understand your answer. admin permission is not the problem in my case. – Attrahent

Answer 1

Why don't you just get the environment variable and then append to it?

I.e.

const {spawnSync} = require("child_process");
const current_value = process.env.PATH;
const new_path_value = current_value.concat(";", "/some/new/path");

var result = spawnSync('setx', ['-m', 'PATH', new_path_value])

// STDOUT
var stdOut = result.stdout.toString();
console.log(stdOut)

// STDERR
var stdErr =  result.stderr.toString();

if(stdErr === '') {
    console.log('Successfully set environment variable')
} else {
    console.log(`ERROR: ${stderr}`)
}

Update "/some/new/path" and run this as admin as the link you provided suggests and it should work.

Unhinge

Are you able to source the current environment variable from process.env? What happens when you console.log(current_value) and console.log(new_value)? – Unhinge

It was my bad, your solution was correct! thank you very much – Attrahent

I needed to change the line console.log(`ERROR: ${stderr}`) to console.log(`ERROR: ${stdErr}`) – Immigration

Answer 2

Run your script with the admin permission:

• Open cmd or PowerShell with admin
• Run node your_script.js
• To append PATH variable, you can set value is : %PATH%;your_new_value here (%PATH% get old value)

If you run with electron app, you should require admin permission.

Don't forget setx run on window

Viperous

What is the difference between appending to an old value and set a new value? – Attrahent

@Attrahent You can add %PATH% to get old value and append your new value – Viperous

Ok, now I understand. That's was the first thing that I did with Electron. I know that the command in windows is setx -m '%path%;NEW_VALUE' but doesn't work with Electron – Attrahent

@Attrahent do you run it with admin permission? – Viperous

of course. the admin permission is only required for the "-m", meaning the variable will be system variable and not user variable. that's the easy part. I'm always ending up setting a new value that overrides the old one instead of appending a new value. – Attrahent

Answer 3

I don't have rights to modify my registry, and I also would rather not call an OS command such as setx.

The following adds an additional component to the Windows PATH. I then ran Selenium, which uses the new setting.

// Display current value of PATH
const current_value = process.env.PATH;
console.log("PREV VALUE:")
console.log(current_value)

// Add the additional entry
const addl_entry = String.raw`\my\new\path\component`
process.env["PATH"] = addl_entry + ";" + current_value

// Display the new value
console.log("NEW VALUE:")
console.log(process.env.PATH)

Immigration