获取cpu使用率的C代码

#include
#include
#include
#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：    ");
    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\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(1000);
    }
printf("\n");
}