Question

I’m making a small console-based rpg, to brush up on my programming skills.
I am using structures to store character data. Things like their HP, Strength, perhaps Inventory down the road. One of the key things I need to be able to do is load and save characters. Which means reading and saving structures.

Right now I’m just saving and loading a structure with first name and last name, and attempting to read it properly.

Here is my code for creating a character:

void createCharacter()
{
    char namebuf[20];

    printf("First Name:");

    if (NULL != fgets(namebuf, 20, stdin))
    {
        char *nlptr = strchr(namebuf, '\n');
        if (nlptr) *nlptr = '\0';
    }
    strcpy(party[nMember].fname,namebuf);


    printf("Last Name:");
    if (NULL != fgets(namebuf, 20, stdin))
    {
        char *nlptr = strchr(namebuf, '\n');
        if (nlptr) *nlptr = '\0';
    }
    strcpy(party[nMember].lname,namebuf);

    /*Character created, now save */
    saveCharacter(party[nMember]);
    printf("\n\n");
    loadCharacter();

}

And here is the saveCharacter function:

void saveCharacter(character party)
{
    FILE *fp;
    fp = fopen("data","a");
    fwrite(&party,sizeof(party),1,fp);
    fclose(fp);

}

and the loadCharacter function

void loadCharacter()
{
    FILE *fp;

    character tempParty[50];
    int loop = 0;
    int count = 1;
    int read = 2;

    fp= fopen("data","r");

    while(read != 0)
    {
        read=fread(&tempParty[loop],sizeof(tempParty[loop]),1,fp);
        printf("%d. %s %s\n",count,tempParty[loop].fname,tempParty[loop].lname);
        loop++;
        count++;
    }
    fclose(fp);
}

So the expected result of the program is that I input a name and last name such as ‘John Doe’, and it gets appended to the data file. Then it is read in, maybe something like

1. Jane Doe
2. John Doe

and the program ends.

However, my output seems to add one more blank structure to the end.

1. Jane Doe
2. John Doe
3. 

I’d like to know why this is. Keep in mind I’m reading the file until fread returns a 0 to signify it’s hit the EOF.

Thanks 🙂

Answer 1

Change your loop:

while( fread(&tempParty[loop],sizeof(tempParty[loop]),1,fp) )
{
    // other stuff
}

Whenever you write file reading code ask yourself this question – “what happens if I read an empty file?”