#if defined(_GNU_SOURCE) || defined(_BSD_SOURCE)
ssize_t preadv (int, const struct iovec *, int, off_t);
ssize_t pwritev (int, const struct iovec *, int, off_t);
+#if defined(_LARGEFILE64_SOURCE) || defined(_GNU_SOURCE)
+#define preadv64 preadv
+#define pwritev64 pwritev
+#define off64_t off_t
+#endif
#endif
#ifdef _GNU_SOURCE