typedef struct cpu_occupy_ //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_t;
double cal_cpuoccupy (cpu_occupy_t *o, cpu_occupy_t *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_t *cpust)
{
FILE *fd;
int n;
char buff[256];
cpu_occupy_t *cpu_occupy;
cpu_occupy=cpust;
fd = fopen ("/proc/stat", "r");
if(fd == NULL)
{
perror("fopen:");
exit (0);
}
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 get_sysCpuUsage()
{
cpu_occupy_t cpu_stat1;
cpu_occupy_t cpu_stat2;
double cpu;
get_cpuoccupy((cpu_occupy_t *)&cpu_stat1);
sleep(1);
//第二次获取cpu使用情况
get_cpuoccupy((cpu_occupy_t *)&cpu_stat2);
//计算cpu使用率
cpu = cal_cpuoccupy ((cpu_occupy_t *)&cpu_stat1, (cpu_occupy_t *)&cpu_stat2);
return cpu;
}
原文地址：http://blog.51cto.com/qiaopeng688/2140580