saveToBinaryFIle

    FILE *fp;

    struct schoolList *current = head;

    if ((fp = fopen("data.bin", "wb")) == NULL) {
        printErrorMessage(FILE_OPEN_FAILURE);
    }

    while (current != NULL) {
        fwrite(&current->data->id, sizeof(unsigned int), 1, fp);
        fwrite(&current->data->classes, sizeof(unsigned int), 1, fp);
        fwrite(&current->data->students, sizeof(unsigned int), 1, fp);
        fwrite(current->data->name, sizeof(char), SCHOOL_NAME_LENGTH + 1, fp);
        fwrite(current->data->director, sizeof(char), strlen(current->data->director) + 1, fp);

        current = current->next;
    }

    fclose(fp);