+#define AT_FDCWD -100 /* Special value used to indicate
+ openat should use the current
+ working directory. */
+#define AT_SYMLINK_NOFOLLOW 0x100 /* Do not follow symbolic links. */
+#define AT_REMOVEDIR 0x200 /* Remove directory instead of
+ unlinking file. */
+#define AT_SYMLINK_FOLLOW 0x400 /* Follow symbolic links. */
+