C noob here. I'm trying to initialize a simple struct as follows:

typedef struct person_s {
    char *fname;                 ///< first name of the person
    char *lname;                 ///< last name of the person
    char *handle;               ///< handle of the person
    struct person_s **friends;  ///< dynamic collection of friends
    size_t friend_count;        ///< current number of friends
    size_t max_friends;         ///< current limit on friends
} person_t;

I think I understand using malloc for every single member in this struct, except for the double pointer friends struct in it. How do I allocate memory for this double pointer?

Here's my malloc for the other data members:

person_t *newperson(char *fn, char *ln, char *han){
    person_t *p = NULL;
    p = malloc(sizeof(person_t));

    p->fname = malloc(strlen(fn)  1);
    strcpy(p->fname, fn);

    p->lname = malloc(strlen(ln)  1);
    strcpy(p->lname, ln);

    p->handle = malloc(strlen(han)  1);
    strcpy(p->handle, han);

    p->*friends = malloc(sizeof(*friends));

    p->friend_count = malloc(2*sizeof(friend_count));
    p->friend_count = 0;

    p->max_friends = malloc(2*sizeof(max_friends));
    p->friend_count = 0;
}

Edit: my bad, I forgot to include that this is inside a function that initializes this struct.

Edit1: In response to the comments, what I'm trying to achieve here is to make a dynamic "array" of friends that is pointed by the p->friends data member. Additionally, I have a dynamic hash table, would it be a good idea to use it as a collection for putting all the friends linked to this person? The concept of pointers and dynamic allocation is still somewhat confusing to me so sorry for misunderstanding.

CodePudding user response：

Single pointer is enough for dynamic collection:

struct person_s *friends; 

...

p->friends = malloc(max_friends * sizeof(struct person_s));