if argv[1] is zero, what kind of error will it incur
int main(int argc, char **argv) {
    char *next = NULL;
    errno = 0;
    long longi = strtol(argv[1], &next, 0);
    int i = longi;

    printf("longi: %ld\n", longi);
    printf("i: %d\n", i);
    printf("next is |%s|\n", next);

    if (errno != 0) {
        perror("strtol");
    }
    return 0;
}