Nodejs - Get environment variables of running process

Question

I am writing an extension for vscode, and I need to get the environment variables of a process that is already running. But I wasn't able to find a way to do it.

I know how to do it in python using psutil:

for proc in psutil.process_iter(attrs=['name', 'exe']):
    if proc.info['name'].lower() == 'SomeProcess.exe'.lower():
        return proc.environ()

Is there something similar for javascript/nodejs?

Answer 1

You can use child_process module to spawn a terminal and execute the following commands wrt platform and get the variables, parse & use or write a native node module to access the proper APIs of each platform and get the output.

Windows (Using powershell, 2019 is the PID )

(Get-Process -id 2019).StartInfo.EnvironmentVariables

Linux

tr '\0' '\n' < /proc/2019/environ

Mac

ps eww -o command 2019  | tr ' ' '\n'

Thanks to https://serverfault.com/a/66366 & https://stackoverflow.com/a/28193753/12167785 & https://apple.stackexchange.com/a/254253 & https://stackoverflow.com/a/11547409/12167785 & https://stackoverflow.com/a/18765553/12167785

Answer 2

Combining with @SudhakarRS's answer:

var child = require('child_process').execFile('powershell', [ 
    '(Get-Process SomeProcess).StartInfo.EnvironmentVariables' 
], function(err, stdout, stderr) { 
    console.log(stdout);
}); 

If you want to debug it, make sure you peek at err and stderr .

Replacing SomeProcess with notepad works for me, but using notepad.exe does not.

On powershell you can get the processes with a particular name using Get-Process [process name] .

So, for example, if I have 4 instances of notepad running and do Get-Process notepad , I see this:

You can get the process IDs with (Get-Process notepad).Id which returns:

You could use the same code to choose the ID:

var child = require('child_process').execFile(
    'powershell',
    ['(Get-Process notepad).Id'],
    function(err, stdout, stderr) { 
        var ids = stdout.split("\r\n");
        ids.pop(); //remove the blank string at the end
        console.log(ids);
    }
);

^ which returns:

If you just want to grab the first process with a name, it's:

(Get-Process notepad)[0].StartInfo.EnvironmentVariables

^ obviously replace notepad with your process name.

Answer 3

Easyish way(from here , you can use something like shelljs then run:

ps faux | grep 'PROCESS_NAME'

Then extract the process id(I'm just working on a regex) and then do:

cat /proc/THE_PROCESS/environ | tr '\0' '\n'

You'll get the the env vars back as a string something like:

THEVAR=1
ANOTHERVAR=2

I reckon you just split the string by '\n' but I'm checking!

I'll update this once I figure the regex. **Are you on linux/mac or windows?

UPDATE: Check https://github.com/shelljs/shx for cross platform

Answer 4

yep:

process.env will give you what you need:)

you can read some more here .

EDIT : it will give you environment variables only for the process you're in ... did I misunderstood and you want varibales of another process?

Answer 5

There is no builtin way to do that in javascript/nodejs. If you really need to do it, then the best way is to run a command in the terminal and then parse the output to construct the object that you need.