Nodejs - Stream output to browser

Question

var http = require(\"http\");
var sys = require(\'sys\')
var filename = process.ARGV[2];
var exec = require(\'child_process\').exec;
var com = exec(\'uptime\');


ht         


        

Answer 1

If you're just generally asking whats going wrong, there are two main things:

1. You're using child_process.exec() incorrectly
2. You never called res.end()

What you're looking for is something more like this:

var http = require("http");
var exec = require('child_process').exec;

http.createServer(function(req, res) {
  exec('uptime', function(err, stdout, stderr) {
    if (err) {
      res.writeHead(500, {"Content-Type": "text/plain"});
      res.end(stderr);
    }
    else {
      res.writeHead(200,{"Content-Type": "text/plain"});
      res.end(stdout);
    }
  });
}).listen(8000);
console.log('Node server running');

Note that this doesn't actually require 'streaming' in the sense that the word is generally used. If you had a long running process, such that you didn't want to buffer stdout in memory until it completed (or if you were sending a file to the browser, etc), then you would want to 'stream' the output. You would use child_process.spawn to start the process, immediately write the HTTP headers, then whenever a 'data' event fired on stdout you would immediately write the data to HTTP stream. On an 'exit' event you would call end on the stream to terminate it.