http://www.cnblogs.com/ShaneZhang/archive/2013/06/21/3147648.html
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