How to see if child process is running?

Question

Node.js

I have code:

function checkStunnel(){
    // return true
    return false
}
function stunnelConnection(){
    if(!checkStunnel()){
        execFile('./stunnel/bin/stunnel.exe', (error, stdout, stderr) => {
            if (error) {
                // throw error;
                throw new Error( error );
            }
            console.log('error',error);
            console.log('stdout',stdout);
            console.log('stderr',stderr);
        });
    }
}

In the function, you need to implement a check to see if stunnel is already running and if it is not running, return false.
How can this be implemented?

Answer 1

On *nix usually via the .pid file, or via the service status in systemd\upstart\... .
That is, you should not directly call the process - but do something like '''systemctl service stunnel start''' '''/etc/init.d/stunnel start''' .... that is, run through the "wrapper"
And, accordingly, through "wrapper" and find out the status is running\working\dead