Segmentation fault - split string - c

Question

Can you please help me with fixing below code. Not sure where the segmentation fault is.
char str[] = "00ab00,00cd00";
char **strptr;
int i;
strptr = malloc(sizeof(char*) * 2);
strcnt = 0;
int j=0;
for(i=0;i<sizeof(str);i++) {
char c = *(str+i);
printf("%c", c);
if(c==',') {
strcnt++;
j=0;
}
strptr[strcnt][j++] = c;
}
Please ignore my poor coding :)
PS: I know its possible to split using strtok() easily.

Answer 1

Not sure where the segmentation fault is
As others have mentioned in the comments, you are not assigning memory to the pointers strptr[0] and strptr[1] but, you are trying to access them. This leads to segmentation fault.
Use a for loop to initially assign memory to strptr[0] and strptr[1]
strptr = malloc(sizeof(char*) * 2);
for(i = 0; i < 2; i++) //here, initialise each to 1 byte
{
strptr[i] = malloc(1);
}
strcnt = 0;
Here's a question on how to initialise a pointer to a pointer.
then, resize them at each step as you add additional character using the realloc() function.
for(i = 0, j = 0; i < sizeof(str); i++)
{
strptr[strcnt] = realloc(strptr[strcnt], j + 2);
//here, you resize each time to provide space for additional character using realloc()
char c = *(str + i);
printf("%c", c);
if(c == ',')
{
++strcnt;
j=0;
continue; //use a continue here
}
strptr[strcnt][j] = c;
strptr[strcnt][++j] = '\0';
//to provide null terminating character at the end of string (updated to next position at every iteration)
}
don't forget to free() the allocated memory
for( i=0; i<2; i++)
{
printf("%s\n", strptr[i]); //just to display the string before `free`ing
free(strptr[i]);
}
free(strptr);
Altogether your code would be something like this:
char str[] = "00ab00,00cd00";
char **strptr;
int i, j;
int strcnt;
strptr = malloc(sizeof(char*) * 2);
for(i = 0; i < 2; i++)
{
strptr[i] = malloc(1);
}
strcnt = 0;
for(i = 0, j = 0; i < sizeof(str); i++)
{
strptr[strcnt] = realloc(strptr[strcnt], j + 2);
char c = *(str + i);
printf("%c", c);
if(c == ',')
{
++strcnt;
j=0;
continue;
}
strptr[strcnt][j] = c;
strptr[strcnt][++j] = '\0';
}
for( i=0; i<2; i++)
{
printf("%s\n", strptr[i]);
free(strptr[i]);
}
free(strptr);
return 0;