read from /dev/urandom

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

#define SIZE 3

int main(void) {
    FILE *fp = fopen("/dev/urandom", "rb");
    if (fp == NULL) {
        perror("fopen");
        exit(EXIT_FAILURE);
    }

    static uint64_t buff[SIZE];
    size_t bytes = fread(buff, sizeof(*buff), SIZE, fp);
    if (bytes != SIZE) {
        fprintf(stderr, "Error reading from /dev/urandom\n");
        exit(EXIT_FAILURE);
    }

    for (size_t i = 0; i < bytes; i++) {
        printf("%llu ", buff[i]);
    }
    putchar('\n');

    if (fclose(fp) == EOF) {
        perror("fclose");
    }
    return 0;
}