#include <stdio.h>

main(){
FILE *fp;
char filename[] = "bintest.dat";
int buf_w[10], buf_r[10];
int i;

for(i = 0; i < 10; i++)
buf_w[i] = (i+1) * 10;
if(!(fp = fopen(filename, "wb")))
return;
if(fwrite(buf_w, sizeof(int), 10, fp) != 10){
fclose(fp);
return;
}
fclose(fp)

if(!(fp = fopen(filename, "rb")))
return;
if(fread(buf_r, sizeof(int), 10, fp) != 10){
fclose(fp) ;
return;
}
fclose(fp);

for(i = 0; i < 10; i++)
printf("%d", buf_r[i]);

}