#include <stdio.h>
#include <string.h>
#include <malloc.h>

/*  This fails if str isn't correctly terminated */
int nums1(const char *str, size_t unused) {
    char *a;
    a = (char *)str;
    int num = 0;

    printf("%x: ", a);
    if(!str) return num;
    while(*a) {
        if(*a == ',') num++;
        printf("(%c) %x ", *a, a);
        a++;
    }
    printf("\n");

    return num;
}

/*  This fails if str isn't correctly terminated */
int nums2(const char *str, size_t unused) {
    int i;
    int num = 0;
    printf("%x: ", str);
    if(!str) return num;
    for(i = 0; i < strlen(str); i++) {
        printf("(%c) %x ", str[i], &str[i]);
        if(str[i] == ',') num++;
    }
    printf("\n");

    return num;
}

/*  likely the safest assuming a correct len is passed in */
int nums3(const char *str, size_t len) {
    int i;
    int num = 0;

    printf("%x: ", str);

    if(!str) return num;

    for(i = 0; i < strnlen(str, len); i++) {
        printf("(%c) %x ", str[i], &str[i]);
        if(str[i] == ',') num++;
    }
    printf("\n");

    return num;
}

/*  I'm not so sure @koorogi */
int nums4(const char *str, size_t len) {
    int num = 0;

    printf("%x: ", str);
    if(!str) return num;

    const char *a = strchr(str, ',');
    while (a) {
        /* Print the whole string of what's left */
        printf("(%s) %x ", a, a);
        a = strchr(a + 1, ',');
        num++;
    }
    printf("\n");

    return num;
}

#define nums(x, y) nums4(x, y)
#define STRSIZE 9

int main(int argc, char *argv[]) {
    printf("%d\n", nums("", 0));
    printf("%d\n", nums("5, 10", 6));

    char str1[] = "5, 10";
    printf("%d\n", nums(str1, strlen(str1)));

    const char *str2 = "5, 10";
    printf("%d\n", nums(str2, strlen(str2)));

    char str3[STRSIZE] = "5, 10";
    /* Overflow str3 by 1 */
    int i;
    for(i = 0; i <= STRSIZE; i++)
        str3[i] = 0x61;
    printf("%d\n", nums(str3, STRSIZE));

    char str4[STRSIZE] = "5, 10";
    /* Overflow str4 by 1 after "5, 10" */
    for(i = 5; i <= STRSIZE; i++)
        str4[i] = 0x61;
    printf("%d\n", nums(str4, STRSIZE));

    /*  Not terminated */
    char str5[STRSIZE] = "012345678";
    printf("%d\n", nums(str5, STRSIZE));

    /* Never trust the user... */
    printf("%d\n", nums(NULL, 0));

    return 0;
}