uint8_t / uint16_t / uint32_t /uint64_t

这些数据类型是 C99 中定义的，具体定义在：/usr/include/stdint.h    ISO C99: 7.18 Integer types <stdint.h>

 1 /* There is some amount of overlap with <sys/types.h> as known by inet code */

 2 #ifndef __int8_t_defined

 3 # define __int8_t_defined

 4 typedef signed char             int8_t; 

 5 typedef short int               int16_t;

 6 typedef int                     int32_t;

 7 # if __WORDSIZE == 64

 8 typedef long int                int64_t;

 9 # else

10 __extension__

11 typedef long long int           int64_t;

12 # endif

13 #endif

14 

15 /* Unsigned.  */

16 typedef unsigned char           uint8_t;

17 typedef unsigned short int      uint16_t;

18 #ifndef __uint32_t_defined

19 typedef unsigned int            uint32_t;

20 # define __uint32_t_defined

21 #endif

22 #if __WORDSIZE == 64

23 typedef unsigned long int       uint64_t;

24 #else

25 __extension__

26 typedef unsigned long long int  uint64_t;

27 #endif

格式化输出：

unit64_t     %llu   

unit32_t     %u

unit16_t    %hu