Help with linked list

**GaPe** · 02-08-2002

Oh man, pointer to pointer?? Is this only possible with pointer to pointer definition?

**~~Troll_King~~** · 02-08-2002

You don't have to use a pointer to pointer, but if you don't use one than you have to use a return type for example:

//prototype
List * Function(List *);

List *ptr_to_List_complex_type;

ptr_to_List_complex_type = Function(ptr_to_List_complex_type);

Whereas a pointer to pointer is cleaner:

void Functon(List **)
List *ptr_to_List_complex_type;

Function(&ptr_to_List_complet_type);

In both cases the List up updated in main.

**GaPe** · 02-08-2002

Ok, just a moment. Are you playing with me?? At first you write "void ReadList (List *, char *)" and then you write in a "OpenFunction" "start = ReadList(fin,start);". This is totally wrong.

**GaPe** · 02-08-2002

For me it's cleaner the return type. I understand it better

.

**~~Troll_King~~** · 02-08-2002

I edited it because I'm writing very quickly and I cut and paste while some of it still has not been updated. Sorry about that. I'm working on it right now I'll show you the changes I've made. The biggest change is to take the control out of your ReadList function and place part of it in main. You had too many things going on in your ReadList function. The file pointer should be passed into the function rather than opening the file in that function and building the list. I'll show you in a few minutes.

**~~Troll_King~~** · 02-08-2002

Does the file just contain integers?

**GaPe** · 02-08-2002

yes.

**~~Troll_King~~** · 02-08-2002

First number is 0, second is 10. LOL, Okay give me a few more minutes. I've been working with character files for a long time. Just need to sort out a few things.

**~~Troll_King~~** · 02-08-2002

hmm,

0
10
6
1
0
-842150451

Are these correct conversion for the binary file or is the last number not correct? I have not used binaries for some time.

**GaPe** · 02-08-2002

When I print out these numbers I get 0, 10, 6, 1, 0.

**~~Troll_King~~** · 02-08-2002

Okay I'll work on it and post when I get the answer. I'm having trouble picking up eof with fread. I have not used binaries for a looong time.

**~~Troll_King~~** · 02-08-2002

I now have put the numbers into a linked list but I am still having trouble with NULL! Just need to fiure that out.

**~~Troll_King~~** · 02-08-2002

It might be that you have to know the size of your datafile, that is how many records it holds. If I know how many records it holds than I have no problem. The problem occurs when it reads feof. The last record is causing the error. With textfiles I know the work around but I'm stumped with the binary file. I know of one work around, that would be to write the file first and get the count for the number of records. One you have the count than fread is not a problem and building a linked list is not a problem.