Windows下用C语言获取系统的CPU利用率、内存使用率、硬盘使用率等

最近在做一个网管软件用C语言获取的系统的一些参数，其中包括系统时间，系统运行时间，系统版本，CPU利用率，内存使用率，硬盘使用率，CPU风扇转速等参数，整理代码如下：`

#include <stdio.h>
#include <Windows.h>
#include<time.h>
#include <tchar.h>

#define DIV 1024
#define WIDTH 7
#define GB(x) (((x).HighPart << 2) + ((DWORD)(x).LowPart) / 1024.0 / 1024.0 / 1024.0)

#pragma warning(disable: 4996)

#define true 1
typedef unsigned char U_CHAR;

//获取系统时间
int getSystemTime(char* buffer){

char buf[128];
time_t rawtime;
struct tm * timeinfo;
time(&rawtime);
timeinfo = localtime(&rawtime);
strftime(buf, sizeof(buf), "Now is %Y-%m-%d %H:%M:%S", timeinfo);
strcpy(buffer,buf);
}

//CPU利用率
FILETIME m_preidleTime;
FILETIME m_prekernelTime;
FILETIME m_preuserTime;

__int64 CompareFileTime2(FILETIME time1, FILETIME time2)
{
__int64 a = time1.dwHighDateTime << 32 | time1.dwLowDateTime;
__int64 b = time2.dwHighDateTime << 32 | time2.dwLowDateTime;

return   b - a;
}

void GetCpuUseage()
{
GetSystemTimes(&m_preidleTime, &m_prekernelTime, &m_preuserTime);
Sleep(1000);
}

double CpuUseage()
{
FILETIME idleTime;
FILETIME kernelTime;
FILETIME userTime;
GetSystemTimes(&idleTime, &kernelTime, &userTime);

int idle = CompareFileTime2(m_preidleTime, idleTime);
int kernel = CompareFileTime2(m_prekernelTime, kernelTime);
int user = CompareFileTime2(m_preuserTime, userTime);

if (kernel + user == 0)
return 0.0;
//（总的时间-空闲时间）/总的时间=占用cpu的时间就是使用率
double cpu = abs((kernel + user - idle) * 100 / (kernel + user));

m_preidleTime = idleTime;
m_prekernelTime = kernelTime;
m_preuserTime = userTime;
return cpu;
}

//读取操作系统的名称
void GetSystemName(char* osname)
{
char buf[128];
SYSTEM_INFO info;        //用SYSTEM_INFO结构判断64位AMD处理器
GetSystemInfo(&info);    //调用GetSystemInfo函数填充结构
OSVERSIONINFOEX os;
os.dwOSVersionInfoSize = sizeof(OSVERSIONINFOEX);

strcpy(buf, "unknown OperatingSystem.");

if (GetVersionEx((OSVERSIONINFO *)&os))
{
//下面根据版本信息判断操作系统名称
switch (os.dwMajorVersion)//判断主版本号
{
case 4:
switch (os.dwMinorVersion)//判断次版本号
{
case 0:
if (os.dwPlatformId == VER_PLATFORM_WIN32_NT)
strcpy(buf, "Microsoft Windows NT 4.0"); //1996年7月发布
else if (os.dwPlatformId == VER_PLATFORM_WIN32_WINDOWS)
strcpy(buf, "Microsoft Windows 95");
break;
case 10:
strcpy(buf, "Microsoft Windows 98");
break;
case 90:
strcpy(buf, "Microsoft Windows Me");
break;
}
break;

case 5:
switch (os.dwMinorVersion)  //再比较dwMinorVersion的值
{
case 0:
strcpy(buf, "Microsoft Windows 2000"); //1999年12月发布
break;

case 1:
strcpy(buf, "Microsoft Windows XP"); //2001年8月发布
break;

case 2:
if (os.wProductType == VER_NT_WORKSTATION
&& info.wProcessorArchitecture == PROCESSOR_ARCHITECTURE_AMD64)
{
strcpy(buf, "Microsoft Windows XP Professional x64 Edition");
}
else if (GetSystemMetrics(SM_SERVERR2) == 0)
strcpy(buf, "Microsoft Windows Server 2003"); //2003年3月发布
else if (GetSystemMetrics(SM_SERVERR2) != 0)
strcpy(buf, "Microsoft Windows Server 2003 R2");
break;
}
break;

case 6:
switch (os.dwMinorVersion)
{
case 0:
if (os.wProductType == VER_NT_WORKSTATION)
strcpy(buf, "Microsoft Windows Vista");
else
strcpy(buf, "Microsoft Windows Server 2008"); //服务器版本
break;
case 1:
if (os.wProductType == VER_NT_WORKSTATION)
strcpy(buf, "Microsoft Windows 7");
else
strcpy(buf, "Microsoft Windows Server 2008 R2");
break;
}
break;
}
}//if(GetVersionEx((OSVERSIONINFO *)&os))

strcpy(osname, buf);
}

int main(){

//获取系统时间
char buffer[128];
getSystemTime(buffer);
puts(buffer);

//系统运行时间
clock_t start, finish;
double duration;

start = clock();
while (true)
{
finish = clock();
duration = (double)(finish - start) / CLOCKS_PER_SEC;
Sleep(1000);
printf("%.0f 秒\n", duration);

}

//系统版本名称
char osname[20];
GetSystemName(osname);
printf("%s\n", osname);

//CPU利用率
while (true)
{
U_CHAR  sysStateCpu[5];
double cpu = CpuUseage();
sprintf((char*)sysStateCpu, "%.2lf", cpu);
printf("CPU使用率：%s%%\n", sysStateCpu);
Sleep(1000);
}

//内存使用率
char bufPreCPU[5];
MEMORYSTATUSEX statex;
statex.dwLength = sizeof(statex);
GlobalMemoryStatusEx(&statex);
sprintf(bufPreCPU, "%ld%%\n", statex.dwMemoryLoad);
puts(bufPreCPU);

//硬盘使用率 调用windows API
ULARGE_INTEGER FreeBytesAvailableC, TotalNumberOfBytesC, TotalNumberOfFreeBytesC;
ULARGE_INTEGER FreeBytesAvailableD, TotalNumberOfBytesD, TotalNumberOfFreeBytesD;
ULARGE_INTEGER FreeBytesAvailableE, TotalNumberOfBytesE, TotalNumberOfFreeBytesE;
ULARGE_INTEGER FreeBytesAvailableF, TotalNumberOfBytesF, TotalNumberOfFreeBytesF;

GetDiskFreeSpaceEx(_T("C:"), &FreeBytesAvailableC, &TotalNumberOfBytesC, &TotalNumberOfFreeBytesC);
GetDiskFreeSpaceEx(_T("D:"), &FreeBytesAvailableD, &TotalNumberOfBytesD, &TotalNumberOfFreeBytesD);
GetDiskFreeSpaceEx(_T("E:"), &FreeBytesAvailableE, &TotalNumberOfBytesE, &TotalNumberOfFreeBytesE);
GetDiskFreeSpaceEx(_T("F:"), &FreeBytesAvailableF, &TotalNumberOfBytesF, &TotalNumberOfFreeBytesF);
/*参数 类型及说明
lpRootPathName String，不包括卷名的磁盘根路径名
lpFreeBytesAvailableToCaller LARGE_INTEGER，指定一个变量，用于容纳调用者可用的字节数量
lpTotalNumberOfBytes LARGE_INTEGER，指定一个变量，用于容纳磁盘上的总字节数
lpTotalNumberOfFreeBytes LARGE_INTEGER，指定一个变量，用于容纳磁盘上可用的字节数
适用平台
Windows 95 OSR2，Windows NT 4.0*/
float totalHardDisk = GB(TotalNumberOfBytesC) + GB(TotalNumberOfBytesD) + GB(TotalNumberOfBytesE) + GB(TotalNumberOfBytesF);
float freeHardDisk = GB(TotalNumberOfFreeBytesC) + GB(TotalNumberOfFreeBytesD) + GB(TotalNumberOfFreeBytesE) + GB(TotalNumberOfFreeBytesF);

float hardDiskUsage = 1- freeHardDisk / totalHardDisk;

//CPU风扇转速

printf("hello world!\n");
system("pause");

}

在播放视频的情况下，默认采用的是主码流播放，当打开多窗口的情况下，会出现电脑卡顿的情形。这时候需要保证客户端播放视频流畅，可以考虑适当的降低码流，所以将主码流切换到辅码流。检测CPU以及内存使用情况显得有必要性了，因此采用上面的方法，获取系统的运行状况，特别是CPU使用率，一般情况下，当CPU使用率超过80%的时候，就得考虑切换码流，保证视频播放的流畅性。