+#define O_ACCMODE 03
+#define O_RDONLY 00
+#define O_WRONLY 01
+#define O_RDWR 02
+
+#define F_RDLCK 0
+#define F_WRLCK 1
+#define F_UNLCK 2
+
+#define FD_CLOEXEC 1
+
+#define AT_FDCWD (-100)
+#define AT_SYMLINK_NOFOLLOW 0x100
+#define AT_REMOVEDIR 0x200
+#define AT_SYMLINK_FOLLOW 0x400
+#define AT_EACCESS 0x200
+
+#define POSIX_FADV_NORMAL 0
+#define POSIX_FADV_RANDOM 1
+#define POSIX_FADV_SEQUENTIAL 2
+#define POSIX_FADV_WILLNEED 3
+#define POSIX_FADV_DONTNEED 4
+#define POSIX_FADV_NOREUSE 5
+