splitting a string by white spaces - c

Question

Before reading this question please note that my question pertains to a school assignment. For this assignment the only function we are allowed to use is malloc(). Everything else must be done without the use of other libraries.
I'm calling a function ft_split_whitespaces. This function takes a string as input and "splits" it into words. Words are separated spaces, tabs and line breaks.
#include <stdio.h>
char **ft_split_whitespaces(char *str);
int main(void)
{
char *str = "what is";
char **test = ft_split_whitespaces(str);
}
With respect to the example above the result at each index should be
test[0] = "what"
test[1] = "is"
test[2] = NULL
However, I am only able to print the results of test[0]. All other indices do not get printed to display. Heres an example of some code that I assume should print the results of my function.
int i = 0;
while(test[i] != NULL)
{
printf("%s", test[i]);
i++;
}
When this portion of code is ran, only test[0] is printed to the output. I've been sitting here trying to debug my code for hours. If anyone has some spare time and doesn't mind looking over my code, I'd appreciate it tremendously. I have a feeling it may be an issue with how I'm using malloc, but I still cant figure it out.
#include <stdlib.h>
#include <stdio.h>
int count_whitespaces(char *str)
{
int space_count;
int i;
space_count = 0;
i = 0;
while(str[i] != '\0')
{
if(str[i] == ' ' || str[i] == 9 || str[i] == '\n')
{
if(str[i+1] != ' ' && str[i+1] != 9 && str[i+1] != '\n')
space_count++;
}
i++;
}
return (space_count);
}
int check_whitespace(char c)
{
if (c == ' ' || c == 9 || c == '\n' || c == '\0')
{
return (1);
}
else
return(0);
}
int count_characters(char *str, int i)
{
int char_count;
char_count = 0;
while(str[i])
{
if(str[i+1] != ' ' && str[i+1] != 9 && str[i+1] != '\n')
char_count++;
else
break;
i++;
}
return (char_count);
}
char **ft_split_whitespaces(char *str)
{
int i;
int j;
int k;
char **word;
int space;
i = 0;
j = 0;
k = 0;
word = (char**)malloc(sizeof(char*)*(count_whitespaces(str) + 2));
while(str[i] != '\0')
{
if (check_whitespace(str[i]) == 1)
i++;
else
{
if((word[j] = malloc(sizeof(char) * (count_characters(str, i) + 1))) == NULL)
return (NULL);
while (check_whitespace(str[i]) == 0)
{
word[j][k] = str[i];
i++;
k++;
}
j++;
}
}
j++;
word[j] = NULL;
j = 0
return word;
}

Answer 1

You forgot to reset k. The outer while loop in ft_split_whitespaces should look like that
while (str[i] != '\0') {
if (check_whitespace(str[i]) == 1){
i++;
}
else {
if ((word[j] =
malloc(sizeof(char) * (count_characters(str, i) + 1))) == NULL){
return (NULL);
}
while (check_whitespace(str[i]) == 0) {
word[j][k] = str[i];
i++;
k++;
}
word[j][k] = '\0';
j++;
k = 0; // reset k
}
}

Answer 2

So I actually figured out what was going wrong with my code as I finished typing this question (thanks stack overflow!). I decided to post it anyways, because I thought it might be a good learning experience for coding newbies such as myself.
This is where my issue was occurring.
word = (char**)malloc(sizeof(char*)*(count_whitespaces(str) + 2));
while(str[i] != '\0')
{
if (check_whitespace(str[i]) == 1)
i++;
else
{
if((word[j] = malloc(sizeof(char) * (count_characters(str, i) + 1))) == NULL)
return (NULL);
while (check_whitespace(str[i]) == 0)
{
word[j][k] = str[i];
i++;
k++;
}
j++;
}
}
I malloc'd my char **word outside of the while loop using the following code
word = (char**)malloc(sizeof(char*)*(count_whitespaces(str) + 2));
And then within the actual while loop I malloc'd it again using
word = (char**)malloc(sizeof(char*)*(count_whitespaces(str) + 2));
Using malloc multiple times on the same variable was causing all sorts of weird issues. So within the while loop I ended up using a new variable I declared as char *words. Here is that portion of the while loop with the correct code.
word = (char**)malloc(sizeof(char*)*(count_whitespaces(str) + 2));
while(str[i] != '\0')
{
if (check_whitespace(str[i]) == 1)
i++;
else
{
words = malloc(sizeof(char) * (count_characters(str, i) + 1));
k = 0;
while (check_whitespace(str[i]) == 0)
{
words[k] = str[i];
i++;
k++;
}
words[k] = '\0';
word[j] = words;
j++;
}
}