readether
n = readether(d, &ptr, (void **)&ah, tleft, &etype);
n = readether(d, &ptr, &data, tleft, &etype);
ssize_t readether(struct iodesc *, void **, void **, time_t, uint16_t *);
n = readether(d, &ptr, (void **)&ap, tleft, &etype);