Missing data after loading

Question

I have the following structs:

typedef struct PList {
    struct PList* next;
    Person value;
} PList;

typedef struct Person{
        char name[100]; // Left as "" if empty Person
        PersonID ID;
        float amountOwed;
}Person;

typedef struct PersonID{
        char letter;
        int number; // 7 digits
}PersonID;

Before i leave the program everything is stored correctly, however after leaving(hence saving), then reopening (hence loading), the Person.ID.number becomes 0

Here are saving and loading portions (customers is a PList):

SAVING

file = fopen("SaveData/customers.dat", "w");
int a;
    a = lengthPList(&customers);
    fwrite(&a, sizeof(int), 1, file);
    PList* temp;
    temp = &customers;
    for (; a > 0; a--) {
        int b;
        b = sizeof(temp->value);
        fwrite(&b, sizeof(int), 1, file);
        fwrite(&temp->value, sizeof(temp->value), 1, file);
        if (a > 1)
            temp = temp->next;
    }

LOADING

file = fopen(fileName, "r");
int a;
            fread(&a, sizeof(int), 1, file);
            for (; a > 0; a--) {
                Person a;
                int b;
                fread(&b, sizeof(int), 1, file);
                fread(&a, b, 1, file);
                addPersonToList(&a, &customers);
            }

OLD CODE

Saving

file = fopen(fileName, "w");
int a;
a = lengthPList(&customers);
fwrite(&a, sizeof(int), 1, file);
fwrite(&customers, sizeof(customers), a, file);

Loading

file = fopen(fileName, "r");
int a;
fread(&a, sizeof(int), 1, file);
fread(&customers, sizeof(customers), a, file);

`fwrite()` and `fread()` are for writing and reading arrays, not linked lists. You have to write a loop. — Barmar, Jan 08 '13 at 11:16
the saved data is being saved for multiple entries though even though it's a linked list. it's just the ID that is being lost. — mangusbrother, Jan 08 '13 at 11:21
updated the saving and loading code to be a loop as suggested. however the ID number is still being read incorrectly. no longer 0 however — mangusbrother, Jan 08 '13 at 12:50
i'm just writing normal text to a text file though. i can't see why rb and wb would be needed... — mangusbrother, Jan 08 '13 at 13:02
Given `int a;`, `fwrite(&a, sizeof(int), 1, file)` is not writing text. It's writing the bytes which compose the representation of a number, which is binary data. — aschepler, Jan 08 '13 at 16:29
so should i use rb and wb throughout everything even since it's writing text? — mangusbrother, Jan 08 '13 at 18:21
and even with rb and wb it's still not reading the id right. — mangusbrother, Jan 08 '13 at 18:28

Missing data after loading

0 Answers0