Thread: I have a file I/O question as well

here is the code I am having a problem with, I cannot get the save or load of my files to work. Can anyone help me find my errors? I am new to programming but here is what I have:


void filesave(void)
{
FILE *fpout;

if(first==(struct account *)NULL)
puts("There are no records to print!");
else
{
if ( (fpout = fopen("test.txt","w+")) == NULL )
{
printf("\n error opening the test.txt file!");
exit(0);
}

current=first;

do
{

/* copy to file */

fprintf (fpout,"%i\n", out->custID);
fprintf (fpout,"%s\n", out->lastname);
fprintf (fpout,"%s\n", out->firstname);
fprintf (fpout,"%s\n", out->street);
fprintf (fpout,"%s\n", out->city);
fprintf (fpout,"%s\n", out->state);
fprintf (fpout,"%s\n", out->zip);
fprintf (fpout,"%s\n", out->rented);
fprintf (fpout,"%f\n", out->balance);

}
while((current=current->next) != (struct account *)NULL);
}

puts("Files Copied!");
system("pause");

fclose(fpout);
return 0;
}

void openrecords(void)
{
FILE *fpin;

if ((fpin = fopen("test.txt","r")) == NULL)
{
printf("\n error opening the test.txt file!");
exit(0);
}

/* a while() statement to find eof */
{

newptr = (struct account *)malloc(sizeof(struct account));

if(first==(struct account *)NULL)
{
first = current = newptr;
current->prior = NULL;
}

else
{
current = first;

while(current->next != (struct account *)NULL)
current = current->next;

last = current;
current->next = newptr; /*save the address of the new record*/
current = newptr;
current->prior = last;
}

fscanf(fpin, "%i", out->custID);
fscanf(fpin, "%s", out->lastname);
fscanf(fpin, "%s", out->firstname);
fscanf(fpin, "%s", out->street);
fscanf(fpin, "%s", out->city);
fscanf(fpin, "%s", out->state);
fscanf(fpin, "%s", out->zip);
fscanf(fpin, "%s", out->rented);
fscanf(fpin, "%f", out->balance);

current->next = (struct account *)NULL;
}


fclose(fpin);
return 0;
}

> if(first==(struct account *)NULL)
There's no need to cast NULL

And you may as well add the {}, even if it's only one statement. It saves finding some tricky bugs later on when you try and add another statement, and forget the {}

> fprintf (fpout,"%i\n", out->custID);
Shouldn't this be
fprintf (fpout,"%i\n", current->custID);