#include <stdio.h>
#include <stdlib.h>


void load(int *load0, int *load1){

	FILE *stat;

	//0 user,1 nice,2 system,3 idle,4 prev idle,5 total,6 prev total,7 prev total - total
	int core0[8]={0,0,0,0,0,0,0};
	int core1[8]={0,0,0,0,0,0,0};

	char dump[10];
	char buffer[100];

	stat = fopen("/proc/stat", "r");
	fgets(buffer, 100, stat);//discard first line
	fgets(buffer, 100, stat);
	sscanf(buffer, "%s %d %d %d %d", dump, &core0[0], &core0[1], &core0[2], &core0[4]);
	fgets(buffer, 100, stat);
	sscanf(buffer, "%s %d %d %d %d", dump, &core1[0], &core1[1], &core1[2], &core1[4]);
	fclose(stat);

	//calculate prev total
	core0[6]=core0[0]+core0[1]+core0[2]+core0[4];
	core1[6]=core1[0]+core1[1]+core1[2]+core1[4];


	//sleep 500ms
	usleep(500000);

	stat = fopen("/proc/stat", "r");
	fgets(buffer, 100, stat);//discard first line
	fgets(buffer, 100, stat);
	sscanf(buffer, "%s %d %d %d %d", dump, &core0[0], &core0[1], &core0[2], &core0[3]);
	fgets(buffer, 100, stat);
	sscanf(buffer, "%s %d %d %d %d", dump, &core1[0], &core1[1], &core1[2], &core1[3]);
	fclose(stat);

	//calculate total
	core0[5]=core0[0]+core0[1]+core0[2]+core0[3];
	core1[5]=core1[0]+core1[1]+core1[2]+core1[3];


	//calculate prev total - total
	core0[7]=core0[6]-core0[5];
	core1[7]=core1[6]-core1[5];


	//100*((prev total - total)-(prev idle - idle))/(prev total - total)
	*load0=100*(core0[7]-(core0[4]-core0[3]))/(core0[7]==0?1:core0[7]);
	*load1=100*(core1[7]-(core1[4]-core1[3]))/(core1[7]==0?1:core1[7]);
}


int main(void) {


	int load0,load1;

        while (1) {

           load(&load0, &load1);
	   printf("CPU0 =%i\%\tCPU1 =%i\%\n",load0,load1);
	}
return 0;
}