store line in linked list (c)

I think that I am having some issues with how linked lists work, please bear in mind that I am not an expert with C and that I have not worked with linked lists before.

I'm trying to take a text file with a list of things and store it in a linked list. I have 开发者_高级运维the following code right now:

typedef struct linked_list {
    struct linked_list *next_ptr;
    char name;
    float price1;
    float price2;
}linked_list;

struct linked_list *first_ptr;
char name_temp;

int writeList(void) {
    // read input files
    FILE *sh_list;
    sh_list=fopen("case1/shoppingList.dat", "rw");
    if (sh_list == NULL) {
        perror("Cannot open file, you seem to have something mixed up...");
        exit(8);
    }

    struct linked_list *current_ptr;
    current_ptr = first_ptr;

    while ((fscanf(sh_list, "%s", &name_temp)) !=EOF) {
        next_ptr = malloc(sizeof(linked_list));
        strcpy(name, name_temp);
        //move to next node and complete the same task
    }
};

I stopped at the //move... because I am struggling to get the code correct - my IDE is giving me errors. Similarly, I can't get it to read the variable "name" which I need to do in order to copy the string to the node.

---

You are getting next_ptr as undeclared because you have not delcared it.

Your code should look something like this ...

linked_list   *next_ptr;
char          name_temp[MAX_SIZE];

while ((fscanf(sh_list, "%s", &name_temp)) !=EOF) {
         next_ptr = malloc(sizeof(linked_list));
         strcpy(next_ptr->name, name_temp);
         next_ptr->next_ptr = first_ptr;
         first_ptr = next_ptr;
} 

You should also make the declaration of name in linked list to be:

char      name[MAX_SIZE];

---

In your fscanf statement you specify that you're inputting a string, %s, but name_temp has type char. You're going to have to change it to a char array, like so:

char name_temp[100];

You'll have to make the array sufficiently big for your purposes. You'll also have to change the type of name:

char name[100];

The error you are getting is because name and next_ptr are part of the struct linked_list but you you have to create an instantiation of linked_list to access name. In your case, you have the current_ptr so you should change it to:

current_ptr->next_ptr = malloc(sizeof(linked_list));
strcpy(current_ptr->name, name_tmp);

---

it should be strcpy(current_ptr->name, name_temp);

You are trying to refer to the name variable in the structure, which needs to be accessed through the current_ptr.

so similarly it should be current_ptr->next_ptr = malloc(sizeof(linked_list));

To access variable in a structure, you need to use the . operator. When you are using a pointer to a structure, then you access its variables using the ->operator.