Node (v0.12) run child processes and receive output

child.js

var child_process = require("child_process");

command("dir");
commandSync("ping 127.0.0.1");

function command(cmd){
	var child = child_process.exec(cmd);
	child.stdout.pipe(process.stdout);
	child.stderr.pipe(process.stderr);
	return child;
}

function commandSync(cmd){
	var childSync = child_process.execSync(cmd);
	process.stdout.write(childSync);
}