How to overrite a .txt file

[ctaylor4874]

I was wondering if anyone can give me tips on how to overwrite/update a .txt file. I give the user the option to add/delete data in a .txt file, and I want to be able to over write the .txt file with the changes they make. This is what I have, and it's not working.

void writeData(int& count)
{
	ofstream aptInfo("RENTALS.TXT");

	if (aptInfo.is_open())
	{
		for (int i = 0; i < count; i++)
		{
			aptInfo << array1[i].phoneNum << " " << array1[i].price << " " << array1[i].vacancy << endl;
			//writes data to file
		}
	}
	else
		cout << "Could not open file. \n";
}

[ctaylor4874]

Here is my entire program, if that helps.

#include <iostream>
#include <fstream>
#include <iomanip>
#include <string>
#include <cctype>
#include <iomanip>
#include <cstdlib>
using namespace std;

const int MAX = 500;
const string APT_INFO = "RENTALS.TXT";
void readFile(int& count);
char newFile();
void userOption(int& count);
void addNew(int& count);
void deleteList(int& count);
void writeData(int& count);

struct houses{
	string phoneNum;
	double price;
	string vacancy;
};

houses array1[MAX];


int main()
{
	char choiceOne; // Whether of not the user wants to load file
	int count = 0;
	
	cout << "This program will give a list of homes to the user.  It will provide the "
		"user with the phone number, price, and whether or not the home is rented."
		<< endl << endl;

	choiceOne = newFile();

	if (choiceOne == 'Y')
		readFile(count);
	userOption(count);

	
	cout << endl << endl;
	system("PAUSE");
	return(0);
}

char newFile()
{
	char userLoad;
	
	cout << "Load existing data from a file (Y/N)? ";
	cin >> userLoad;
	cout << endl << endl;

	userLoad = toupper(userLoad);

	while ((userLoad != 'Y') && (userLoad != 'N'))
	{
		cout << "Invalid entry, please enter a 'Y' or a 'N': " << endl << endl;
		cout << "Load existing data from a file (Y/N)? ";
		cin >> userLoad;
		cout << endl << endl;
	}

	return(userLoad);
}

void readFile(int& count)
{
	ifstream aptInfo;
	double cost;
	string phNum;
	string avail;
	int i = 0;

	aptInfo.open(APT_INFO.c_str()); //opens the file for reading

	if (aptInfo) //if the file opens successfully
	{
		aptInfo >> phNum >> cost >> avail; //priming read

		while ((aptInfo) && (count <= MAX))
		{
			i++;

			if (avail == "0")
				avail = "Not Rented";
			else
				avail = "Rented";

			array1[i].phoneNum = phNum;
			array1[i].price = cost;
			array1[i].vacancy = avail;

			count = i;

			aptInfo >> phNum >> cost >> avail;
		}
	}


	if (count == MAX)
	{
		cout << "There are too many records in the file, all further"
			"records will be ignored." << endl;
	}
}

void userOption(int& count)
{
	char choice = 'A';
	
	cout << "Phone Number\t\tMonthly Rent\t\tStatus\n"
		"-------------\t\t------------\t\t---------\n";
	for (int i = 1; i <= count; i++)
	{
		cout << array1[i].phoneNum << "\t\t" << array1[i].price << "\t\t\t" << array1[i].vacancy << endl;
	}


	while ((choice == 'A') || (choice == 'B'))
	{
		cout << "\nMENU \n ---------- \n A. Add New Home \n B. Delete a Rental \n C. Exit \n"
			"What is your choice? ";
		cin >> choice;
		cout << endl << endl;
		choice = toupper(choice);
		
		if (choice == 'C')
		{
			exit(0);
		}
		if (choice == 'A')
		{
			addNew(count);
			writeData(count);
			readFile(count);
		}
		else if (choice == 'B')
		{
			deleteList(count);
			writeData(count);
			readFile(count);
		}

	};
}

void addNew(int& count)
{
	string phNum;
	char rentStatus;
	double rent;
	string convert;

	cout << "Please enter the phone number associated with the apartment in the formate xxx-xxx-xxxx: ";
	cin >> phNum;
	cout << endl;

	count++;
	array1[count].phoneNum = phNum;

	cout << "Please enter how much the rent is: ";
	cin >> rent;
	cout << endl;

	while (rent <= 0)
	{
		cout << "Invalid entry. Rent must be a positive number: ";
		cin >> rent;
		cout << endl;
	}
	array1[count].price = rent;

	cout << "Is the apartment rented (Y/N): ";
	cin >> rentStatus;
	rentStatus == toupper(rentStatus);

	while ((rentStatus != 'Y') && (rentStatus != 'N'))
	{
		cout << "Invalid entry.  Enter a 'Y' or a 'N': ";
		cin >> rentStatus;
		rentStatus = toupper(rentStatus);
	}

	if (rentStatus == 'Y')
		convert = '1';
	else
		convert = '0';
	cout << endl;
	array1[count].vacancy = convert;

}

void deleteList(int& count) //write code to delete a listing next
{
	int placeFound;               // index where found
	string itemToDel;
	bool deleted;

	deleted = false;              // item not found and deleted yet

	cout << "What is the phone number for the listing you want to delete? ";
	cin >> itemToDel;
	cout << endl;

	// Find where itemToDel is in list
	placeFound = 0;                             // Start search at first index

	while ((placeFound < count) &&           // While still values to search
		(array1[placeFound].phoneNum != itemToDel))     // and value not found
	{
		placeFound++;                        // increment index

		if (placeFound == count)
		{
			cout << "Phone number not found.  Please try again: ";
			cin >> itemToDel;
			cout << endl;
			placeFound = 0;
		}
	}

	//If itemToDel was Found, delete it
	if (placeFound < count)
	{

		// Move all values below itemToDel UP one cell
		for (int num = placeFound + 1; num < count; num++)
		{
			array1[num - 1].phoneNum = array1[num].phoneNum;
			array1[num - 1].price = array1[num - 1].price;
			array1[num - 1].vacancy = array1[num - 1].vacancy;
		}

		// Decrement list size
		count--;

		// Zero out deleted last item
		array1[count].phoneNum = "";	// Optional
		array1[count].price = 0;
		array1[count].vacancy = "";

		deleted = true;
	}
}

void writeData(int& count)
{
	ofstream aptInfo("RENTALS.TXT");

	if (aptInfo.is_open())
	{
		for (int i = 0; i < count; i++)
		{
			aptInfo << array1[i].phoneNum << " " << array1[i].price << " " << array1[i].vacancy << endl;
			//writes data to file
		}
	}
	else
		cout << "Could not open file. \n";
}

[SamuelAdams]

Are you saying it doesn't overwrite everything in the text file ?

What exactly do you mean isn't working ?

[SamuelAdams]

can you explain the int& for me in line 250?

[kevinkjt2000]

Opening a file in truncate mode may be what you want?
std::fstream file("something.txt", std::fstream::trunc);

[Duthomhas]

He's opening with an ofstream, so the 'trunc' is automatic.

[ctaylor4874]

SamuelAdams, I am trying to enable the user to edit the txt file by adding, or deleting data. How it should work is the I load the data into array1[] from the .txt file, the user deletes/adds data into the array1[], then I would like to be able to write array1[] into the same txt file that is originally loaded into the array.

The int& in line 250 is there because I thought I would need it. It should be just a int.

The program should be able to loop through until the user wants to exit. So the user should be able to add/delete listings over and over, until he/she wants to close the program.

[kevinkjt2000]

1. Load file into array and close file
2. Modify array as requested by user
3. Write array back to an std::ofstream file and close file
What part is causing your trouble?

[ctaylor4874]

Ok, I figured it out. I didn't realize it was as easy as kevinkjt explained. It's working now! Thank you guys.