Whats wrong with this code?
I cant get it to display the contents in assign6 file. Its supposed to order whats already in the file and save it back out to disk.
In the file it says
Smith, Bob
233-444-5555
43
Manager
Code:
#include "stdafx.h"
#include <fstream>
#include <iostream>
using namespace std;
struct record
{
char name[50];
char ssn[12];
char age[4];
char occupation[50];
struct record *next; /* pointer to next entry */
struct record *prior; /* pointer to previous record */
};
struct record *start; /* pointer to first entry in list */
struct record *last; /* pointer to last entry */
struct record *find(char *);
void enter(void), search(void), save(void);
void load(void), list(void);
void dls_store(struct record *i, struct record **start,
struct record **last);
void inputs(char *, char *, int), display(struct record *);
int menu();
class LL
{
private:
record *head;
record *tail;
public:
LL();
int insert(record data);
record *search(char[]);
int delete_item(char[]);
};
LL::LL ( )
{
head = NULL;
tail = NULL;
}
int main(int argc, char* argv[])
{
load();
start = last = NULL; /* initialize start and end pointers */
int temp =0;
do {
temp = menu ();
switch(temp)
{
case 1: list();
break;
case 4: save();
break;
default:
cout << temp << " is invalid!" << endl;
}
} while (temp != 4);
return 0;
}
/* Create a doubly linked list in sorted order. */
void dls_store(
struct record *i, /* new element */
struct record **start, /* first element in list */
struct record **last /* last element in list */
)
{
struct record *old, *p;
if(*last==NULL) { /* first element in list */
i->next = NULL;
i->prior = NULL;
*last = i;
*start = i;
return;
}
p = *start; /* start at top of list */
old = NULL;
while(p) {
if(strcmp(p->name, i->name)<0){
old = p;
p = p->next;
}
else {
if(p->prior) {
p->prior->next = i;
i->next = p;
i->prior = p->prior;
p->prior = i;
return;
}
i->next = p; /* new first element */
i->prior = NULL;
p->prior = i;
*start = i;
return;
}
}
old->next = i; /* put on end */
i->next = NULL;
i->prior = old;
*last = i;
}
/* Display the entire list. */
void list(void)
{
struct record *info;
info = start;
while(info) {
display(info);
info = info->next; /* get next address */
}
printf("\n\n");
}
/* This function actually prints the fields in each address. */
void display(struct record *info)
{
printf("%s\n", info->name);
printf("%s\n", info->ssn);
printf("%s\n", info->age);
printf("%s\n", info->occupation);
printf("\n\n");
}
/* Load the address file. */
void load()
{
struct record *info;
FILE *fp;
fp = fopen("assign6", "rb");
if(!fp) {
printf("Cannot open file.\n");
exit(1);
}
/* free any previously allocated memory */
while(start) {
info = start->next;
free(info);
start = info;
}
/* reset top and bottom pointers */
start = last = NULL;
printf("\nLoading File\n");
while(!feof(fp)) {
info = (struct record *) malloc(sizeof(struct record));
if(!info) {
printf("Out of Memory");
return;
}
if(1 != fread(info, sizeof(struct record), 1, fp)) break;
dls_store(info, &start, &last);
}
fclose(fp);
}
/* Save the file to disk. */
void save(void)
{
struct record *info;
FILE *fp;
fp = fopen("assign6", "wb");
if(!fp) {
printf("Cannot open file.\n");
exit(1);
}
printf("\nSaving File\n");
info = start;
while(info) {
fwrite(info, sizeof(struct record), 1, fp);
info = info->next; /* get next address */
}
fclose(fp);
}
int menu ()
{
int item;
// display menu and return output
cout << "===============================" << endl;
cout << " Please Select An Option " << endl << endl;
cout << " 1. Display a record" << endl;
cout << " 2. Add a record" << endl;
cout << " 3. delete a record" << endl;
cout << " 4. Exit" << endl;
cin >> item;
cin.ignore ();
// return item
return item;
}
I think i might need to put this part
void dls_store(
in the class somehow?
dyou opened the stream...
I see you opened the strean but did not read ->ifstream , write->ofstream or close() the outsteam in your code. I think the problem lies after here
Quote:
fp = fopen("assign6", "wb");
Also, I think you have to have the filename extesions added to assign6.txt like so...
Thats all I can really help since i am learning about <fsteam> class myself but I believe i am correct.
I hope this helps.
cj
;)
