## js_system.cc

JS_METHOD(_exec) {
	if (args.Length() != 1) {
		return JS_EXCEPTION("Wrong argument count. Use system.exec(\"command\")");
	}

	std::string data;
	FILE *stream;
	int MAX_BUFFER = 256;
	char buffer[MAX_BUFFER];

	v8::String::Utf8Value cmd(args[0]);
	stream = popen(*cmd, "r");
	while ( fgets(buffer, MAX_BUFFER, stream) != NULL ) {
		data.append(buffer);
	}
	pclose(stream);
	return JS_STR(data.data());
}


## js_system.cc | inside setup_system()

system->Set(JS_STR("exec"), v8::FunctionTemplate::New(_exec)->GetFunction());