#pragma once
#define O_RDONLY (1 << 0)
#define O_WRONLY (1 << 1)
#define O_RDWR (O_RDONLY | O_WRONLY)
#define O_ACCMODE (O_RDONLY | O_WRONLY)
#define O_EXCL (1 << 2)
#define O_CREAT (1 << 3)