How to send output of shell command to client in Node.js

Question

I'd like to send output of shell command to client.

Here is the code snippet which handles POST request:

app.post('/', function(req, res) {

    console.log("request is received");
    const ps = spawn('sh', ['test.sh', req.body.code]);
    ps.stdout.on('data', (data) => {
        console.log(`stdout: ${data}`);
    });

    ps.stderr.on('data', (data) => {
        console.log(`stderr: ${data}`);
    });

    ps.on('close', (code) => {
        console.log(`child process exited with code ${code}`);
    });

    // echo incoming data to test whether POST request works
    res.status(200).json({ myReply: req.body.code });

});

How can I send stdout to client in such a case?

Answer 1

You can stream the stdout from the child process back to res. This works because ps.stdout is a readable stream and res is a writable stream.

ps.stdout.pipe(res)