musl/include/bits/fcntl.h

#define O_ACCMODE 03
#define O_RDONLY  00
#define O_WRONLY  01
#define O_RDWR    02

#define O_CREAT        0100
#define O_EXCL         0200
#define O_NOCTTY       0400
#define O_TRUNC       01000
#define O_APPEND      02000
#define O_NONBLOCK    04000
#define O_SYNC       010000
#define O_DIRECTORY 0200000
#define O_NOFOLLOW  0400000
#define O_CLOEXEC  02000000

#ifdef _GNU_SOURCE
#define O_ASYNC      020000
#define O_DIRECT     040000
#define O_NOATIME  01000000
#define F_DUPFD_CLOEXEC 1030
#define FAPPENT O_APPEND
#define FFSYNC O_FSYNC
#define FASYNC O_ASYNC
#define FNONBLOCK O_NONBLOCK
#define FNDELAY O_NDELAY
#endif

#define F_DUPFD  0
#define F_GETFD  1
#define F_SETFD  2
#define F_GETFL  3
#define F_SETFL  4

#define F_SETOWN 8
#define F_GETOWN 9

#define F_GETLK 12
#define F_SETLK 13
#define F_SETLKW 14

#define FD_CLOEXEC 1

#define F_RDLCK 0
#define F_WRLCK 1
#define F_UNLCK 2

#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