#define O_RDONLY  0x000
#define O_WRONLY  0x001
#define O_RDWR    0x002
#define O_NOFOLLOW 0x010
#define O_CREATE  0x200
#define O_TRUNC   0x400

#ifdef LAB_MMAP
#define PROT_NONE       0x0
#define PROT_READ       0x1
#define PROT_WRITE      0x2
#define PROT_EXEC       0x4

#define MAP_SHARED      0x01
#define MAP_PRIVATE     0x02
#endif