Thread: Problem with a loop reading lines of a file

Hey guys,

This may seem familiar to a few of you, I posted the same bit of code a couple days ago, but I have a different problem with it this time. The loop reads lines of a file that contains usernames and passwords. This is the whole function. Also, I know goto statements aren't optimal, but I plan on changing it to eliminate them once I have it running.

Code:

void newName() {
	string userName, password;
	string existingName;
	int i = 0;

	cout << "Opening username list info. . ." << endl;
	ifstream userNameDB("users.data");

	/*if (!userNameDB) {
	    cout << "Error opening 'users.data'." << endl;
	    cout << "Writing error report. . ." << endl;
		writeError(0);
		cout << "Returning to login:" << endl;
		logIn();
        }*/

	usernameCreate:
	i = 0;
	cout << endl << "Enter your desired username(4-12 characters, LETTERS ONLY): ";
	cin >> userName;

	if (userName.length() > 12 || userName.length() < 4) {
		cout << endl << "Invalid input, check username length." << endl;
		goto usernameCreate;
	}

	for (i = 0; userNameDB >> existingName; i++) {
		if (userName == existingName) {
		        cout << "Name already exists, please pick a different one. " << endl;
			goto usernameCreate;
		}
	}

    userNameDB.close();

	passwordCreate:
	cout << "Enter a password(4-12 characters, LETTERS ONLY): ";
	cin >> password;

	if (password.length() < 4 || password.length() > 12) {
		cout << "Invalid input, check username length." << endl;
		goto passwordCreate;
	}

	cout << "Saving info. . ." << endl;
	createName(userName, password);

}

If the file looks like this:

Code:

//users.data
Username
Password
Username2
Password2
Username3
Password3

And I try to create another username "Username", it catches it the first time and tells me that it already exists. But if I try to create a username "Username" right after the first attempt, it's not caught that it already exists. I've been staring and thinking for at least an hour, I can't figure it out. Please help .

Thanks in advance.

Just because you go back to usernameCreate does not magically make the input file rewind itself. Fortunately there is a rewind function.

That makes sense.. brb working some google magic.

Found something that works:

Code:

userNameDB.seekg(0, ios::beg);

Anything wrong with this method? Faults that I can't see?

That should work fine.

And it does, thanks