Piping data from child to parent in nodejs

Question

I have a nodejs parent process that starts up another nodejs child process. The child process executes some logic and then returns output to the parent. The output is large

Answer 1

You can do this with fork()

I just solved this one for myself...fork() is the the higher level version of spawn, and it's recommended to use fork() instead of spawn() in general.

if you use the {silent:true} option, stdio will be piped to the parent process

          const cp = require('child_process');

          const n = cp.fork(, args, {
              cwd: path.resolve(__dirname),
              detached: true,
           });

          n.stdout.setEncoding('utf8');

          // here we can listen to the stream of data coming from the child process:
          n.stdout.on('data', (data) => {
            ee.emit('data',data);
          });

          //you can also listen to other events emitted by the child process
          n.on('error', function (err) {
            console.error(err.stack);
            ee.emit('error', err);
          });

          n.on('message', function (msg) {
            ee.emit('message', msg);
          });

          n.on('uncaughtException', function (err) {
            console.error(err.stack);
            ee.emit('error', err);
          });


          n.once('exit', function (err) {
             console.error(err.stack);
             ee.emit('exit', err);
          });