random.c

random.c

#include <stdio.h>
#include <stdint.h>
#include <unistd.h>
#include <fcntl.h>

ssize_t get_random()
{
    int randomData = open("/dev/random", O_RDONLY);
    int myRandomInteger;
    size_t randomDataLen = 0;
    while (randomDataLen < sizeof myRandomInteger)
    {
        ssize_t result = read(randomData, ((char*)&myRandomInteger) + randomDataLen, (sizeof myRandomInteger) - randomDataLen);
        if (result < 0)
        {
            // error, unable to read /dev/random 
        }
        randomDataLen += result;
    }
    close(randomData);

    return result;
}


main()
{
    printf("%d\n", get_random());
    printf("%d\n", get_random());
    printf("%d\n", get_random());
    printf("%d\n", get_random());
}