#include <windows.h>

#include <conio.h>

#include <stdio.h>

#define SystemBasicInformation 0

#define SystemPerformanceInformation 2

#define SystemTimeInformation 3

#define Li2Double(x) ((double)((x).HighPart) * 4.294967296E9 + (double)((x).LowPart))



typedef struct{ 

	DWORD dwUnknown1; 

	ULONG uKeMaximumIncrement; 

	ULONG uPageSize; 

	ULONG uMmNumberOfPhysicalPages; 

	ULONG uMmLowestPhysicalPage; 

	ULONG uMmHighestPhysicalPage; 

	ULONG uAllocationGranularity; 

	PVOID pLowestUserAddress; 

	PVOID pMmHighestUserAddress; 

	ULONG uKeActiveProcessors; 

	BYTE bKeNumberProcessors; 

	BYTE bUnknown2; 

	WORD wUnknown3;

} SYSTEM_BASIC_INFORMATION;



typedef struct{ 

	LARGE_INTEGER liIdleTime; 

	DWORD dwSpare[76];

} SYSTEM_PERFORMANCE_INFORMATION;



typedef struct{ 

	LARGE_INTEGER liKeBootTime; 

	LARGE_INTEGER liKeSystemTime; 

	LARGE_INTEGER liExpTimeZoneBias; 

	ULONG uCurrentTimeZoneId; 

	DWORD dwReserved;

} SYSTEM_TIME_INFORMATION;



typedef LONG (WINAPI *PROCNTQSI)(UINT,PVOID,ULONG,PULONG);

PROCNTQSI NtQuerySystemInformation;



void main()

{ 

	SYSTEM_PERFORMANCE_INFORMATION SysPerfInfo; 

	SYSTEM_TIME_INFORMATION SysTimeInfo; 

	SYSTEM_BASIC_INFORMATION SysBaseInfo; 

	double dbIdleTime; 

	double dbSystemTime; 

	LONG status; 

	LARGE_INTEGER liOldIdleTime = {0,0}; 

	LARGE_INTEGER liOldSystemTime = {0,0}; 

	NtQuerySystemInformation = (PROCNTQSI)GetProcAddress(GetModuleHandle("ntdll"),"NtQuerySystemInformation"); 

	if (!NtQuerySystemInformation) return; 

	// get number of processors in the system 

	status = NtQuerySystemInformation(SystemBasicInformation,&SysBaseInfo,sizeof(SysBaseInfo),NULL); 

	if (status != NO_ERROR) 

		return; 

	int amount=0;

	printf("\n您的CPU使用率为： \n"); 

	while(!_kbhit()) 

	{ 

		//设置新的系统时间： 

		amount++;

		status = NtQuerySystemInformation(SystemTimeInformation,&SysTimeInfo,sizeof(SysTimeInfo),0); 

		if (status!=NO_ERROR) 

			return; 

		status = NtQuerySystemInformation(SystemPerformanceInformation,&SysPerfInfo,sizeof(SysPerfInfo),NULL); 

		if (status != NO_ERROR) 

			return;

		if (liOldIdleTime.QuadPart != 0)

		{ 

			dbIdleTime = Li2Double(SysPerfInfo.liIdleTime) - Li2Double(liOldIdleTime);

			dbSystemTime = Li2Double(SysTimeInfo.liKeSystemTime) - Li2Double(liOldSystemTime); 

			dbIdleTime = dbIdleTime / dbSystemTime; 

			dbIdleTime = 100.0 - dbIdleTime * 100.0 / (double)SysBaseInfo.bKeNumberProcessors; 

			int c=(int)dbIdleTime; 

			printf("\b\b\b\b\b\b\b\b\b\b\b\b\b%d---%d%%",amount,c);

		} 

		//改变新的CPU使用率和系统时间 

		liOldIdleTime = SysPerfInfo.liIdleTime; 

		liOldSystemTime = SysTimeInfo.liKeSystemTime;

		Sleep(500); 

	}

	printf("\n");

}