speed

int main (int argc, char **argv)
{
    struct stat sb;
    if (argc !=3 ) exit(EXIT_FAILURE);
    char c[]="                                                        ";
    time_t t;
    stat(argv[1],&sb);
    strcat(c,"cp ");
    strcat(c,argv[1]);
    strcat(c," ");
    strcat(c,argv[2]);
    long a=(long)time(&t);
    system(c);
    long b=(long)time(&t);
    if(!(b-a)) {
    puts("Divide by zero");
    exit(EXIT_FAILURE);
    }
    printf("Speed:%5.2f MB per second.\n",(double)sb.st_size/1024/1024/(double)(b-a));
    exit(EXIT_SUCCESS);
    }