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

int main(int argc, char* argv[]) {
    uint8_t a[3] = {65, 66, 67};       // initialize array
    uint8_t b[3] = {0x50, 0x51, 0x52};
    char    c    = '9';
    char    d[3] = {'J', 'K', 'L'};
    char*   e    = "XYZ";
    FILE* fp = fopen("file.txt", "w");
    fwrite(a,     sizeof(uint8_t), 2, fp);
    fwrite(b,     sizeof(uint8_t), 2, fp);
    fwrite(&c,    sizeof(char),    1, fp);
    fwrite(d,     sizeof(uint8_t), 2, fp);
    fwrite(e + 1, sizeof(char),    2, fp);
    fclose(fp);
    return EXIT_SUCCESS;
}