C generovani nahodnych cisel 2

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

FILE *fp;
FILE *csv;

int generujNahodneCislo() {
    int byte_count = sizeof(int);
    int random[1];
    fread(&random, 1, byte_count, fp);
    //printf("%d\n", random[0]);
    //printf("%.10f\n", (double) random[0] / 10000000000);
    return random[0];
}

int main(int argc, char *argv[]) {
    fp = fopen("/dev/urandom", "r");
    csv = fopen("dev_urandom.csv", "w+");
    time_t start, stop;

    int kolik = 1;

    if (argc > 1) {
        kolik = atol(argv[1]);
    }

    printf("Kolik: %d\n", kolik);

    int cisla[kolik];

    time(&start);
    for (int i=0; i< kolik; i++) {
        cisla[i] = generujNahodneCislo();
    }
    time(&stop);

    for (int i=0; i< kolik; i++) {
        //fprintf(csv, "%d,%d\n", i, cisla[i]);
        double abc = (double) cisla[i] / 10000000000;
        fprintf(csv, "%.10f\n", abc);
        printf("Nahodne cislo c. %d = %.10f\n", i, abc);
    }

    printf("Vygenerovano: %d cisel\n", kolik);
    printf("Generovani trvalo %.000fs\n", difftime(stop, start));

    fclose(fp);
    fclose(csv);

    return 0;
}

// gcc -o dev_urandom dev_urandom.c -std=c99

/* VYSTUP:

Kolik: 10
Nahodne cislo c. 0 = 0.1952607124
Nahodne cislo c. 1 = 0.1485520581
Nahodne cislo c. 2 = 0.1176588805
Nahodne cislo c. 3 = 0.0430723194
Nahodne cislo c. 4 = 0.1302624476
Nahodne cislo c. 5 = -0.1477905392
Nahodne cislo c. 6 = -0.2100886278
Nahodne cislo c. 7 = -0.1149736942
Nahodne cislo c. 8 = -0.0067722964
Nahodne cislo c. 9 = 0.1352800048
Vygenerovano: 10 cisel
Generovani trvalo 0s

*/