linux c编程 获取本机CPU利用率 内存使用情况 硬盘使用情况

1.获取CPU的利用率

typedef struct CPU_PACKED //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 iowait;
unsigned int irq;
unsigned int softirq;
}CPU_OCCUPY;

主程序：
double cal_cpuoccupy (CPU_OCCUPY *o, CPU_OCCUPY *n)
{
double od, nd;
double id, sd;
double cpu_use ;

od = (double) (o->user + o->nice + o->system +o->idle+o->softirq+o->iowait+o->irq);//第一次(用户+优先级+系统+空闲)的时间再赋给od
nd = (double) (n->user + n->nice + n->system +n->idle+n->softirq+n->iowait+n->irq);//第二次(用户+优先级+系统+空闲)的时间再赋给od

id = (double) (n->idle); //用户第一次和第二次的时间之差再赋给id
sd = (double) (o->idle) ; //系统第一次和第二次的时间之差再赋给sd
if((nd-od) != 0)
cpu_use =100.0- ((id-sd))/(nd-od)*100.00; //((用户+系统)乖100)除(第一次和第二次的时间差)再赋给g_cpu_used
else cpu_use = 0;
return cpu_use;
}

void get_cpuoccupy (CPU_OCCUPY *cpust)
{
FILE *fd;
int n;
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->iowait,&cpu_occupy->irq,&cpu_occupy->softirq);

fclose(fd);
}

double getCpuRate()
{
CPU_OCCUPY cpu_stat1;
CPU_OCCUPY cpu_stat2;
double cpu;
get_cpuoccupy((CPU_OCCUPY *)&cpu_stat1);
sleep(1);

//第二次获取cpu使用情况
get_cpuoccupy((CPU_OCCUPY *)&cpu_stat2);

//计算cpu使用率
cpu = cal_cpuoccupy ((CPU_OCCUPY *)&cpu_stat1, (CPU_OCCUPY *)&cpu_stat2);

return cpu;
}

2.获取内存的使用情况
typedef struct MEM_PACKED //定义一个mem 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 long total;
char name2[20];
}MEM_OCCUPY;

typedef struct MEM_PACK //定义一个mem occupy的结构体
{
double total,used_rate;
}MEM_PACK;主程序：
MEM_PACK *get_memoccupy () // get RAM message
{
FILE *fd;
int n;
double mem_total,mem_used_rate;;
char buff[256];
MEM_OCCUPY *m=(MEM_OCCUPY *)malloc(sizeof(MEM_OCCUPY));;
MEM_PACK *p=(MEM_PACK *)malloc(sizeof(MEM_PACK));
fd = fopen ("/proc/meminfo", "r");

fgets (buff, sizeof(buff), fd);
sscanf (buff, "%s %lu %s\n", m->name, &m->total, m->name2);
mem_total=m->total;
fgets (buff, sizeof(buff), fd);
sscanf (buff, "%s %lu %s\n", m->name, &m->total, m->name2);
mem_used_rate=(1-m->total/mem_total)*100;
mem_total=mem_total/(1024*1024);
p->total=mem_total;
p->used_rate=mem_used_rate;
fclose(fd); //关闭文件fd
return p ;
}
3.获取硬盘的使用情况

typedef struct DEV_MEM //定义一个mem occupy的结构体
{
double total,used_rate;
}DEV_MEM;

主程序：
DEV_MEM *get_devmem() // get hard disk meeeage
{
FILE * fp;
int h=0;
char buffer[80],a[80],d[80],e[80],f[80],buf[256];
double c,b;
fp=popen("df","r");
fgets(buf,256,fp);
double dev_total=0,dev_used=0;
DEV_MEM *dev=(DEV_MEM *)malloc(sizeof(DEV_MEM));
while(6==fscanf(fp,"%s %lf %lf %s %s %s",a,&b,&c,d,e,f))
{
dev_total+=b;
dev_used+=c;
}
dev->total=dev_total/1024/1024;;
dev->used_rate=dev_used/dev_total*100;
pclose(fp);
return dev;
}