lseek (fd, (off_t) (dp->d_id * sizeof(*dp)), SEEK_SET);
if (read (fd, (char *) dl, sizeof(*dl)) != sizeof(*dl)
|| (ntohl(dl->d_stop) != dp->d_stop
lseek (fd, (off_t) (dp->d_id * sizeof(*dp)), SEEK_SET);
if (read (fd, (char *) dl, sizeof(*dl)) != sizeof(*dl)
|| (ntohl(dl->d_stop) != dp->d_stop