c - How to add objects to singly linked list -

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information file being read car struct "newcar". need use "sll_add" function below add information single liked list of type carlist named "list". i'm having trouble understanding how starts. thank help. 

int main (void)//main function {   file *fp;//file pointer fp = fopen("car_inventory.txt", "r");//opens car inventory data within program. int num=0;//vairable created keep track of information. int year;//, choice;//variables use user input. char str1[100];//string created ensure program reads information original file correctly.  carlist list;//creates string of type "car" named file hold 100 cars.  car newcar;//car variable store info file.   list *last=num;  if (fp)     {         {                            while(!feof(fp))//takes input data file.             {         fgets(str1,50, fp);         sscanf(str1,"%d %s %[^\n]s", &newcar.year, newcar.make, newcar.model);          fgets(str1,50, fp);         sscanf(str1,"%[^\n]s", newcar.style);          fgets(str1,50, fp);         sscanf(str1,"%[^\n]s", newcar.color);          fgets(str1,50, fp);         sscanf(str1,"%s", newcar.mileage);          fgets(str1,50, fp);         sscanf(str1,"%c", &newcar.air_condition);          fgets(str1,50, fp);         sscanf(str1,"%s", newcar.inventory_num);          fgets(str1,50, fp);         sscanf(str1,"%lf", &(newcar).price);          fgets(str1,50, fp);         sscanf(str1,"%[^\n]s", newcar.previous_owner);          fgets(str1,50,fp);           num++;         sll_add(*newcar, &list);             }         }  return 0;   #define max_cars     100  /* type definitions */  typedef struct car {     int year;     char make[25];     char model[25];     char style[25];     char color[20];     char mileage[8];     char air_condition;     char inventory_num[16];     double price;     char previous_owner[30];     struct car *next;  } car;   typedef struct carlist {     car *first;     car *last; } carlist;   void sll_init(carlist *l); car *sll_first(carlist *l); car *sll_end(carlist *l); car *sll_next(car *current, carlist *l); car *sll_retrieve(car *element, carlist *l); void sll_delete(car *c, carlist *l); void sll_delete_year(carlist *l, int year); void sll_add(car *newcar, carlist *l);       #endif

start beginning. first, carlist needs initialized, need flesh out sll_init() function. 1 easy since needs set first , last pointers null. might this:

void sll_init(carlist *l) {     l->first = l->last = null; }

next, need able add entries list, need flesh out sll_add(). might this:

void sll_add(car *newcar, carlist *l) {     car *new = malloc(sizeof(*new));     *new = *newcar;     new->next = null;    // safe in case newcar wasn't initialized      if (l->first == null)     {         // list empty, add first entry         l->first = l->last = new;     }     else     {         // list not empty, append new entry end         l->last->next = new;         l->last = new;     } }

with this, should able started.


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