musl/include/fcntl.h

#ifndef	_FCNTL_H
#define	_FCNTL_H

#ifdef __cplusplus
extern "C" {
#endif

#define __NEED_off_t
#define __NEED_pid_t
#define __NEED_mode_t

#include <bits/alltypes.h>

#include <bits/fcntl.h>

struct flock
{
	short l_type;
	short l_whence;
	off_t l_start;
	off_t l_len;
	pid_t l_pid;
};

int creat(const char *, mode_t);
int fcntl(int, int, ...);
int open(const char *, int, ...);
int openat(int, const char *, int, ...);
int posix_fadvise(int, off_t, off_t, int);
int posix_fallocate(int, off_t, off_t);

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

#define F_DUPFD_CLOEXEC 1030

#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

#undef SEEK_SET
#undef SEEK_CUR
#undef SEEK_END
#define SEEK_SET 0
#define SEEK_CUR 1
#define SEEK_END 2

#ifndef S_IRUSR
#define S_ISUID 04000
#define S_ISGID 02000
#define S_ISVTX 01000
#define S_IRUSR 0400
#define S_IWUSR 0200
#define S_IXUSR 0100
#define S_IRWXU 0700
#define S_IRGRP 0040
#define S_IWGRP 0020
#define S_IXGRP 0010
#define S_IRWXG 0070
#define S_IROTH 0004
#define S_IWOTH 0002
#define S_IXOTH 0001
#define S_IRWXO 0007
#endif

#if defined(_GNU_SOURCE) || defined(_BSD_SOURCE)
#define FAPPEND O_APPEND
#define FFSYNC O_FSYNC
#define FASYNC O_ASYNC
#define FNONBLOCK O_NONBLOCK
#define FNDELAY O_NDELAY

#define F_OK 0
#define R_OK 4
#define W_OK 2
#define X_OK 1
#define F_ULOCK 0
#define F_LOCK  1
#define F_TLOCK 2
#define F_TEST  3

int lockf(int, int, off_t);
#endif

#if defined(_LARGEFILE64_SOURCE) || defined(_GNU_SOURCE)
#define open64 open
#define openat64 openat
#define creat64 creat
#define lockf64 lockf
#define posix_fadvise64 posix_fadvise
#define posix_fallocate64 posix_fallocate
#define off64_t off_t
#endif

#ifdef __cplusplus
}
#endif

#endif