u16
首先必须知道u8,s8等数据类型的定义：typedef signed char s8;
typedef unsigned char u8;
typedef signed short s16;
typedef unsigned short u16;
typedef signed int s32;
typedef unsigned int u32;
typedef signed long long s64;
typedef unsigned long long u64;
与体系结构相关的，定义在include/linux/type.h文件中：/* bsd */
typedef unsigned charu_char;
typedef unsigned shortu_short;
typedef unsigned intu_int;
typedef unsigned longu_long;
/* sysv */
typedef unsigned charunchar;
typedef unsigned shortushort;
typedef unsigned intuint;
typedef unsigned longulong;
#ifndef __BIT_types_defined__
#define __BIT_TYPES_DEFINED__
typedef__u8u_int8_t;
typedef__s8int8_t;
typedef__u16u_int16_t;
typedef__s16int16_t;
typedef__u32u_int32_t;
typedef__s32int32_t;
#endif /* !(__BIT_TYPES_DEFINED__) */
typedef__u8uint8_t;
typedef__u16uint16_t;
typedef__u32uint32_t;
#if defined(__GNUC__)
typedef__u64uint64_t;
typedef__u64u_int64_t;
typedef__s64int64_t;
对于各种数据类型的打印方式总结如下如下：数据类型打印格式u8%d
s8%d
u16%d or %hu
s16%d or %hd
u32%u
s32%d
u64%llu
s64%lld
int%d
unsigned int%u
short int%d or %hd
long%ld
unsigned long%lu
long long%lld
unsigned long long%llu
char%c
char *%s
bool (#define stdbool.h)%d
unsigned int/int------>十六进制%0x
unsigned long/long---->十六进制%0lx
long long/unsigned long long ----->十六进制%0llx
unsigned int/int------>八进制%0o
unsigned long/long---->八进制%0lo
long long/unsigned long long ----->八进制%0llo
float%f
double%f or %lf
科学技术类型(必须转化为double类型)%e
限制输出字段宽度%x.yf (x:整数长度,y:小数点长度)
待解问题，在linux kernel里面也有使用bool来定义变量，查看code，定义如下：typedef _Bool bool;
但是并没有真正找到具体定义在何处，待解。下面是stdbool.h的source code：#define _STDBOOL_H
#ifndef __cplusplus
#define bool_Bool
#define true1
#define false0
#else /* __cplusplus */
/* Supporting _Bool in C++ is a GCC extension. */
#define _Boolbool
#if __cplusplus < 201103L
/* Defining these macros in C++98 is a GCC extension. */
#define boolbool
#define falsefalse
#define truetrue
#endif
#endif /* __cplusplus */
/* signal that all the definitions are present. */
#define __bool_true_false_are_defined1
#endif/* stdbool.h */
也大致解释了linux kernel bool type了。