CODEWITHSUNDEEP
node.jsasynchronouscallbackconsole
user2689782
user2689782

Reputation: 757

node.js: console.log from child_process

In node, I am running a perl script using child_process, and console.log in the callback seems to be behaving strangely.

child = exec("perl " + validationScript,
        {cwd: myDir},
        function(err, stdout, stderr) {
            console.log('stdout: ' + stdout);
            console.log('stderr: ' + stderr);

            return cb(err);
        });

stdout is printing correctly, but the stderr print statement is not executing. (If I comment out the stdout print, then stderr is printed correctly). So some buffering problem? How can I make them print correctly?

I am new to asynchronous programming, so sorry if this question is too basic.

Upvotes: 1

Views: 540

Answers (1)

Kiechlus
Kiechlus

Reputation: 1237

have you tried it without return? The following code works for me. aa provokes an error and I have something on the stderr, if I only use ls I'll get no error but a correct stdout.

child = exec('ls aa',
    function(err, stdout, stderr) {
        console.log('stdout: ' + stdout);
        console.log('stderr: ' + stderr);

        cb(err);
    });
function cb(data) {
  console.log(data);
}

Upvotes: 1

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