转自http://www.programfan.com/club/showbbs.asp?id=94578

#include <STDIO.H>
#include <WINDOWS.H>

void main( void )
{
    unsigned long ProcSpeed = 0;
    HKEY hKey;

    LONG rt = RegOpenKeyEx( HKEY_LOCAL_MACHINE, "HARDWARE\\DESCRIPTION\\System\\CentralProcessor\\0", 0, KEY_READ, &hKey);
    if( ERROR_SUCCESS == rt )
    {
        unsigned long buflen = sizeof( ProcSpeed );
        RegQueryValueEx( hKey, "~MHz", NULL, NULL, (LPBYTE)&ProcSpeed, &buflen );
        RegCloseKey(hKey);
    }    

    if( 0 != ProcSpeed )
        printf( "%ldMHz\n", ProcSpeed );
    else
        printf( "查询失败\n", ProcSpeed );
}

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

PROCNTQSI NtQuerySystemInformation;


void main(void)
{
    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};

    //从动态链节库中调用函数
    NtQuerySystemInformation = (PROCNTQSI)GetProcAddress(GetModuleHandle("ntdll"),"NtQuerySystemInformation");

   if (!NtQuerySystemInformation)  return;

   // 获得系统中当前的处理器个数
   status = NtQuerySystemInformation(SystemBasicInformation,&SysBaseInfo,sizeof(SysBaseInfo),NULL);
   if (status != NO_ERROR)  return;

   printf("\nCPU使用率(按任意健退出):   ");
  
   while(!_kbhit())
  {
        // 获得新的系统时间
        status = NtQuerySystemInformation(SystemTimeInformation,&SysTimeInfo,sizeof(SysTimeInfo),0);
        if (status!=NO_ERROR)   return;

        // 获得新的CPU的空闲时间(idle time)
        status = NtQuerySystemInformation(SystemPerformanceInformation,&SysPerfInfo,sizeof(SysPerfInfo),NULL);
        if (status != NO_ERROR)  return;

        // if it's a first call - skip it
        if (liOldIdleTime.QuadPart != 0)
        {
            // CurrentValue = NewValue - OldValue
            dbIdleTime = Li2Double(SysPerfInfo.liIdleTime) - Li2Double(liOldIdleTime);
            dbSystemTime = Li2Double(SysTimeInfo.liKeSystemTime) - Li2Double(liOldSystemTime);

            // CurrentCpuIdle = IdleTime / SystemTime
            dbIdleTime = dbIdleTime / dbSystemTime;
            
            // (CPU利用率的计算公式)CurrentCpuUsage% = 100 - (CurrentCpuIdle * 100) / NumberOfProcessors
            dbIdleTime = 100.0 - dbIdleTime * 100.0 / (double)SysBaseInfo.bKeNumberProcessors + 0.5;

        printf("\b\b\b\b%3d%%",(UINT)dbIdleTime);    
        }

        // store new CPU's idle and system time
        liOldIdleTime = SysPerfInfo.liIdleTime;
        liOldSystemTime = SysTimeInfo.liKeSystemTime;

        // wait one second
        Sleep(1000);
    }
   
printf("\n");
}

评论