javascript - How do I send stdout in real time from nodejs to angularjs? -

i have script runs long time. generates output. running script nodejs using child_process. how send output of script starts executing , not wait script complete. code have waits script complete , outputs stdout @ once on nodejs console.

sample script:

import time  if __name__ == '__main__':     in range(5):         time.sleep(1)         print("hello how " + str(i)) 

nodejs code:

var spawn = require('child_process').spawn,     ls    = spawn('python', ['path/test.py']);  ls.stdout.on('data', function (data) {   console.log('stdout: ' + data); });  ls.stderr.on('data', function (data) {   console.log('stderr: ' + data); });  ls.on('close', function (code) {   console.log('child process exited code ' + code); }); 

console.log waits script complete , outputs

hello how 1 hello how 2 hello how 3 hello how 4 hello how 5 

in 1 shot. there anyway can achieve sending stdout written until child process stops?

the short answer is:

you need reopen sys.stdout in non-bufering mode.

example:

import os import sys  sys.stdout = os.fdopen(sys.stdout.fileno(), 'w', 0) 

so program this:

import os import sys import time  if __name__ == '__main__':     sys.stdout = os.fdopen(sys.stdout.fileno(), 'w', 0)      in range(5):         time.sleep(1)         sys.stdout.write("hello how " + str(i))         sys.stdout.flush()