public Node external_execute(Node startAt) throws Exception {
startAt.isGoodArgsLength(true, 2);
String command = startAt.getSubNode(1, Node.TYPE_STRING).getString();
Private_Execute pexec = new Private_Execute(command);
int res = pexec.exec();
Node rnode = Node.createHash();
Hash hash=rnode.getHash();
hash.store(Node.createQSymbol("result-code"), new Node(res));
hash.store(Node.createQSymbol("output"), new Node(pexec.getOutput()));
hash.store(Node.createQSymbol("error"), new Node(pexec.getError()));