C/C++获取Linux系统CPU和内存及硬盘使用情况

需求分析：

不使用Top df free 等命令，利用C/C++获取Linux系统CPU和内存及硬盘使用情况

实现：

[cpp] view plain copy

//通过获取/proc/stat (CPU)和/proc/meminfo(内存和硬盘)文件信息
//proc/meminfo文件结构
//MemTotal: 515164 kB
//MemFree: 15024 kB
//Buffers: 13740 kB
//Cached: 248824 kB
//SwapCached: 960 kB
//Active: 309980 kB
//Inactive: 63420 kB
typedef struct MEMPACKED //定义一个mem occupy的结构体
{
char name1[20]; //定义一个char类型的数组名name有20个元素
unsigned long MemTotal;
char name2[20];
unsigned long MemFree;
char name3[20];
unsigned long Buffers;
char name4[20];
unsigned long Cached;
char name5[20];
unsigned long SwapCached;
}MEM_OCCUPY;
//proc/stat文件结构
//cpu 633666 46912 249878 176813696 782884 2859 19625 0
//cpu0 633666 46912 249878 176813696 782884 2859 19625 0
//intr 5812844
//ctxt 265816063
//btime 1455203832
//processes 596625
//procs_running 1
//procs_blocked 0
typedef struct CPUPACKED //定义一个cpu occupy的结构体
{
char name[20]; //定义一个char类型的数组名name有20个元素
unsigned int user; //定义一个无符号的int类型的user
unsigned int nice; //定义一个无符号的int类型的nice
unsigned int system;//定义一个无符号的int类型的system
unsigned int idle; //定义一个无符号的int类型的idle
unsigned int lowait;
unsigned int irq;
unsigned int softirq;
}CPU_OCCUPY;
void get_memoccupy(MEM_OCCUPY *mem) //对无类型get函数含有一个形参结构体类弄的指针O
{
FILE *fd;
char buff[256];
MEM_OCCUPY *m;
m = mem;
fd = fopen("/proc/meminfo", "r");
//MemTotal: 515164 kB
//MemFree: 7348 kB
//Buffers: 7892 kB
//Cached: 241852 kB
//SwapCached: 0 kB
//从fd文件中读取长度为buff的字符串再存到起始地址为buff这个空间里
fgets(buff, sizeof(buff), fd);
sscanf(buff, "%s %lu ", m->name1, &m->MemTotal);
fgets(buff, sizeof(buff), fd);
sscanf(buff, "%s %lu ", m->name2, &m->MemFree);
fgets(buff, sizeof(buff), fd);
sscanf(buff, "%s %lu ", m->name3, &m->Buffers);
fgets(buff, sizeof(buff), fd);
sscanf(buff, "%s %lu ", m->name4, &m->Cached);
fgets(buff, sizeof(buff), fd);
sscanf(buff, "%s %lu", m->name5, &m->SwapCached);
fclose(fd); //关闭文件fd
}
int get_cpuoccupy(CPU_OCCUPY *cpust) //对无类型get函数含有一个形参结构体类弄的指针O
{
FILE *fd;
char buff[256];
CPU_OCCUPY *cpu_occupy;
cpu_occupy = cpust;
fd = fopen("/proc/stat", "r");
fgets(buff, sizeof(buff), fd);
sscanf(buff, "%s %u %u %u %u %u %u %u", cpu_occupy->name, &cpu_occupy->user, &cpu_occupy->nice, &cpu_occupy->system, &cpu_occupy->idle, &cpu_occupy->lowait, &cpu_occupy->irq, &cpu_occupy->softirq);
fclose(fd);
return 0;
}
int cal_cpuoccupy(CPU_OCCUPY *o, CPU_OCCUPY *n)
{
unsigned long od, nd;
double cpu_use = 0;
od = (unsigned long)(o->user + o->nice + o->system + o->idle + o->lowait + o->irq + o->softirq);//第一次(用户+优先级+系统+空闲)的时间再赋给od
nd = (unsigned long)(n->user + n->nice + n->system + n->idle + n->lowait + n->irq + n->softirq);//第二次(用户+优先级+系统+空闲)的时间再赋给od
double sum = nd - od;
double idle = n->idle - o->idle;
cpu_use = idle / sum;
printf("cpu_use1(idle) = %f ", cpu_use);
idle = n->user + n->system + n->nice - o->user - o->system - o->nice;
cpu_use = idle / sum;
printf("cpu_use2(user+system+nice) = %f ", cpu_use);
return 0;
}
int main( int argc, char **argv )
{
MEM_OCCUPY mem_stat;
CPU_OCCUPY cpu_stat1;
CPU_OCCUPY cpu_stat2;
CAfcLowerTools m_afcLowerTools;
//获取内存
get_memoccupy((MEM_OCCUPY *)&mem_stat);
printf(" [MemTotal] = %lu [MemFree] = %lu [Buffers] = %lu [Cached] = %lu [SwapCached] = %lu ", mem_stat.MemTotal, mem_stat.MemFree, mem_stat.Buffers, mem_stat.Cached, mem_stat.SwapCached);
//第一次获取cpu使用情况
get_cpuoccupy((CPU_OCCUPY *)&cpu_stat1);
Sleep(1000);
//第二次获取cpu使用情况
get_cpuoccupy((CPU_OCCUPY *)&cpu_stat2);
//计算cpu使用率
cal_cpuoccupy((CPU_OCCUPY *)&cpu_stat1, (CPU_OCCUPY *)&cpu_stat2);
}