storing in text file

[Daviesrt]

Hi,
I'm having some problems storing data to a text file. I have created a program that creates linked lists, but i now need to take this list and save it to a text file. I cant seem to be able to get it to work.
Eventually i would like to be able to retrieve the data from a file and store it in a linked list but thats another problem.
Hope someone can help.
The code I have developed so far is shown below:
#include <iostream.h>

struct node
{
char first_name[30];
char last_name[30];
int age;
node *nxt;
};
node *start_ptr = NULL;
node *current; // Used to move along the list
int option = 0;



void add_node_at_end ()
{ node *temp, *temp2; // Temporary pointers

// Reserve space for new node and fill it with data
temp = new node;
cout << "Please enter the name of the person: ";
cin >> temp->first_name;
cout << "Please enter the age of the person : ";
cin >> temp->age;
cout << "Please enter the surname of the person : ";
cin >> temp->last_name;
temp->nxt = NULL;

// Set up link to this node
if (start_ptr == NULL)
start_ptr = temp;
else
{ temp2 = start_ptr;
// We know this is not NULL - list not empty!
while (temp2->nxt != NULL)
{ temp2 = temp2->nxt;
// Move to next link in chain
}
temp2->nxt = temp;
}
}

void display_list()
{ node *temp;
temp = start_ptr;
cout << endl;
if (temp == NULL)
cout << "The list is empty!" << endl;
else
{ while (temp != NULL)
{ // Display details for what temp points to
cout << "Name : " << temp->first_name << " ";
cout << "Age : " << temp->age << " ";
cout << "Surname : " << temp->last_name;
if (temp == current)
cout << " <-- Current node";
cout << endl;
temp = temp->nxt;

}
cout << "End of list!" << endl;
}
}


void main()
{
start_ptr = NULL;
do
{
cout << endl;
cout << "Please select an option : " << endl;
cout << "0. Exit the program." << endl;
cout << "1. Add a node to the end of the list." << endl;
cout << "2. Display List of nodes. " << endl;
cout << endl << " >> ";
cin >> option;

switch (option)
{
case 1 : add_node_at_end();break;
case 2 : display_list();

}
}
while (option != 0);
}

[Daviesrt]

Got it to work eventually, silli mistakes, oops.
But now Ive got the problem of reading the data back in to the linked list.
Any suggestions?
Rich

[mwilliamson]

Well, how did you write it? I would suggest just reading each record and adding it to the tail of the list. Storing a tail pointer will speed this up.

[Daviesrt]

It nearly works but doesnt quite read the data back into the linked list correctly. Any help would be most appreciated
Thank You
Richard
This is my code so far.

#include <iostream>
using std::cout;
using std::cin;
using std::ios;
using std::cerr;
using std::endl;

#include <fstream>
using std:fstream;
using std::ifstream;

#include<cstdlib>

struct node
{
char first_name[30];
char last_name[30];
int age;
node *nxt;
};
node *start_ptr = NULL;
node *current; // Used to move along the list
int option = 0;



void add_node_at_end ()
{
char fname[30];
node *temp, *temp2; // Temporary pointers

// Reserve space for new node and fill it with data
temp = new node;
cout << "Please enter the name of the person: ";
cin >> temp->first_name;

cout << "Please enter the surname of the person : ";
cin >> temp->last_name;
cout << "Please enter the age of the person : ";
cin >> temp->age;
temp->nxt = NULL;

// Set up link to this node
if (start_ptr == NULL)
start_ptr = temp;
else
{ temp2 = start_ptr;
// We know this is not NULL - list not empty!
while (temp2->nxt != NULL)
{ temp2 = temp2->nxt;
// Move to next link in chain
}
temp2->nxt = temp;
}
}



int output_file()
{
ofstream outClientFile("1.txt", ios:ut);
if(!outClientFile)
{
cerr << "File could not be opened" << endl;
exit(1);
}
node *temp;
temp = start_ptr;
while (temp != NULL)
{
outClientFile << temp->first_name << " " <<
temp->last_name << " " <<
temp->age << " " << '\n';
if (temp == current)
cout << " <-- Current node";
cout << endl;
temp = temp->nxt;
}
return 0;
}

int input_file()
{
node *temp, *temp2;
temp = new node;
ifstream inClientFile("1.txt", ios::in);
if(!inClientFile)
{
cerr << "File could not be opened" << endl;
exit(1);
}
while(inClientFile >> temp->first_name >> temp->last_name >> temp->age)
{
temp->nxt = NULL;
if (start_ptr == NULL)
start_ptr = temp;
else
{ temp2 = start_ptr;
// We know this is not NULL - list not empty!
while (temp2->nxt != NULL)
{ temp2 = temp2->nxt;
// Move to next link in chain
}
temp2->nxt = temp;
}

}
return 0;
}


void display_list()
{ node *temp;
temp = start_ptr;
cout << endl;
if (temp == NULL)
cout << "The list is empty!" << endl;
else
{ while (temp != NULL)
{ // Display details for what temp points to
cout << "Name : " << temp->first_name << " ";
cout << "Surname : " << temp->last_name << " ";
cout << "Age : " << temp->age;
if (temp == current)
cout << " <-- Current node";
cout << endl;
temp = temp->nxt;

}
cout << "End of list!" << endl;
}

}


void main()
{
start_ptr = NULL;
do
{
cout << endl;
cout << "Please select an option : " << endl;
cout << "0. Exit the program." << endl;
cout << "1. Add a node to the end of the list." << endl;
cout << "2. Display List of nodes. " << endl;
cout << "3. Send data to text file. "<<endl;
cout << "4. Get data from file. " << endl;
cout << endl << " >> ";
cin >> option;

switch (option)
{
case 1 : add_node_at_end();break;
case 2 : display_list();break;
case 3 : output_file();break;
case 4 : input_file();

}
}
while (option != 0);
}