Freeing memory which has been allocated to an array of char pointers (strings). Do I have to free each string or just the “main” pointer?

Question

I have a function that takes a pointer to a char ** and fills it with strings (an array of strings I guess). *list_of_strings* is allocated memory inside the function.

Answer 1

Yes, you have to free() every block you obtained from malloc(). You do it by traversing the array of pointers and caling free() on each element and only then freeing the array itself.

Only you know that there's a tree-like structure that could be freed recursively, that knowledge is not anywhere in the C runtime heap, so the heap manager has no idea about that and your program has to free everything itself.