public Node external_list_files(Node startAt) throws Exception {
startAt.isGoodArgsLength(false, 2);
if (startAt.size() > 3) {
throw new InterpreterException(StdErrors.Argument_count_mismatch);
}
Private_FilenameFilter filefilter = null;
File f = new File(startAt.getSubNode(1, Node.TYPE_STRING).getString());
if (startAt.size() == 3) {
filefilter = new Private_FilenameFilter();
filefilter.setMaskList(startAt.getSubNode(2, Node.TYPE_CLIST));
}
Node res = Node.createCList();
File[] fl;
if (filefilter == null) {
fl = f.listFiles();