sorting by name or number

[Unregistered]

Could I get some pointers on a good way to add code to sort records that are read from a file, contact.txt, then print them out on the screen and also rewrite them to file in sorted order by either name or phone number. the user is provided an interface to choose. this is my insert function, i cannot figure how to do call these records to another function, sort_records(). any ideas? thanks
Thanks for any help

void add_to_list (void)
/* Add a new name to our address book */
{
ADDRESS *new_name;

FILE *f;
f=fopen("contact.txt","a+");
new_name= malloc (sizeof (ADDRESS));
if (new_name == NULL) {
printf ("Out of memory!\n");
exit (-1);
}

/* Get input for the new item */
printf("Name: ");
fgets(new_name->name, MAXLEN, stdin);
printf ("Address: ");
fgets (new_name->address, MAXLEN, stdin);
printf ("Telephone: ");
fgets (new_name->phone, MAXLEN, stdin);
printf ("City: ");
fgets (new_name->city, MAXLEN, stdin);
printf ("State: ");
fgets (new_name->state, MAXLEN, stdin);
printf ("Email: ");
fgets (new_name->email, MAXLEN, stdin);
printf("Contact Added\n");
fprintf(f,"Name: %s\n",new_name->name);
fprintf(f,"Address: %s\n",new_name->address);
fprintf(f,"Telephone: %s\n",new_name->phone);
fprintf(f,"City: %s\n",new_name->city);
fprintf(f,"State: %s\n",new_name->state);
fprintf(f,"Email: %s\n",new_name->email);
if(!f)
fclose(f);
new_name->next= hol;
hol= new_name;


}

[QuestionC]

Since it's a linear linked list, you're probably going to end up with a bubble sort...

ADDRESS * p;
int sorted = 0;
for (; sorted == 0; )
{
 sorted = 1;
 for (p = hol; p -> next != NULL; p = p -> next)
 {
  if (compare (p, p -> next))
  {
   swap (p, p -> next);
   sorted = 0;
  }
 }
}

So now we just need to fill in the blanks for compare () and swap ()

compare should be easy to implement. It just returns 1 if the first node pointed to should be after the second node, and 0 otherwise. The logic of that function will depend on by which value you sort the nodes.

swap is a little more complicated. Basically, it's supposed to just swap the two nodes.. there are two ways to do this...

1) Swap all the values in *p with all the values in *(p -> next), except for their -> next fields

2) Make it so that the node before p points to p-> next, p -> next points to p, and p points to the node that was after p -> next

[Unregistered]

how can i get the sort function to read from the file, contact.txt? thanks