for somethjibng

hrng.c

#include <stdio.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdlib.h>
#include <limits.h>

long hrng(long min, long max) {
    int fd = open("/dev/urandom", O_RDONLY);
    unsigned char randb;
    if (read(fd, &randb, sizeof(randb)) != sizeof(randb)) {
        perror("read");
        close(fd);
        exit(1);
    }
    close(fd);

    return min + (randb * (max - min + 1)) / (UCHAR_MAX + 1);
}

int main() {
    printf("%ld\n", hrng(1, 100));
    return 0;
}