How to wait for a child process to finish in Node.js?

Question

I'm running a Python script through a child process in Node.js, like this:

require('child_process').exec('python celulas.py', function (error, stdout, stderr) {     child.stdout.pipe(process.stdout); }); 

but Node doesn't wait for it to finish. How can I wait for the process to finish?

Is it possible to do this by running the child process in a module I call from the main script?

Answer 1

Use exit event for the child process.

var child = require('child_process').exec('python celulas.py') child.stdout.pipe(process.stdout) child.on('exit', function() {   process.exit() }) 

PS: It's not really a duplicate, since you don't want to use sync code unless you really really need it.