c - Accessing struct field within another struct -

so data structure supposed hash table, array of linked list. inside each of linked list holds linked list. , inside linked list book. book contains book name, , linked list of library ids hold book.

i'm having trouble searching within linked list see if book->name exists. know how access called "shelf" it's on by:

int index = hashfunction(char* nameofbook) % this->size; 

and searching within hash array find this:

this->chain[index] 

but how can access book struct once i'm inside linked list?

in list.h

typedef struct nodestruct {     void *data;     struct nodestruct* next;     struct nodestruct* prev; } nodestruct;  typedef struct liststruct {     nodestruct* first;     nodestruct* last;     int elementtype; } liststruct; 

in hash.c:

typedef struct book {     liststruct* libid; // each book has own list of library ids     char* name; // each book has name. } book;  // hashset contains linked list of books. typedef struct hashstruct {     int size;     int load;     liststruct **chain; //an array of linked lists. } hashstruct; 

here constructors:

// constructor new book. book *newbook(char* name) {     book *this = malloc (sizeof (book));     assert(this != null);     this->name = name;     this->libid = malloc(sizeof (liststruct*));     this->libid = newlist(sizeof(int));     return this; }  hashhandle new_hashset(int size) {     hashhandle temphash = malloc (sizeof (hashstruct));     assert (temphash != null);     temphash->size = size;     temphash->load = 0;     temphash->chain = malloc (sizeof (liststruct));     assert(temphash->chain != null);     // each linked list holds linked list.     (int = 0; < size; ++i) {         temphash->chain[i] = newlist(sizeof(book));     }     return temphash; } 

edit: think got work. haven't tested yet.

bool has_hashset (hashhandle this, char *item) {      //finds index at.     int index = strhash(item) % this->size;      nodestruct *cur = this->chain[index]->first;     while (cur != null) {         book *tmp = cur->data;         if (strcmp(tmp->name, item) == 0)             return true;         cur = cur->next;     }     return false; } 

sorry if confusing. way, 'data' of linked list generic. thank you!

because cur->data pointer void, need assign pointer of type book (or cast type). otherwise, not able use -> member because void not struct.

what fixed in edit should work fine.