How to catch command line output with Nodejs?

Question

I want to catch the time when this "done" is outputted in the console, but I am not sure how to do this:

var cp = require('child_process');

cp.exec('avconv -strict experimental -i ' + filename + ' ' + tempname + ';' + ' echo done', function(err, stdout, stderr) {
    console.log(err);
    console.log(stdout);
    console.log(stderr);
});

Tried checking the stdout, but it just brings lots of information about the file.

avconv is a tool for converting files so my goal in here is to check when the converting is done and proceed further on.

Answer 1

stdout does return the output from the command. You should try something simpler at first to see if you're actually calling the command correctly.

Try this:

child_process.exec('ls', function (err, stdout, stderr){
    if (err) {
        console.log("error: " + err.code);
    }
    console.log(stdout);
});

Answer 2

You can get the time when exec's callback will called

var cp = require('child_process');
cp.exec('ls', function(err, stdout, stderr) {
   console.log(new Date())
});