Console Application: unexpected QTextStream(stdin) behavior

ScottCUSA

@
QTextStream qtout(stdout);
QTextStream qterr(stderr);
QTextStream qtin(stdin);

QString getFileName() {

QString fileName = "";
do {
    qtout << "Enter a filename: " << flush;
    fileName = qtin.readLine();
    qtout << "You entered: \"" << fileName << "\"" << endl << endl;
} while (fileName.isEmpty()); // the user must enter a filename

//check to see if the file exists
QFile data(fileName);
if(data.exists()) { //this the file exists
    qtout << "A file with that name already exists. " << endl
          << "If you continue it will be over-written." << endl
          << "Do you wish to continue? " << endl
          << "1) yes \n2) no \n3) to change filename" << endl
          << endl;

    int choice = 0;
    do {
        qtout << "Enter 1, 2 or 3: " << flush;
        qtin >> choice;
        qtout << endl << flush;
        if(qtin.status() != QTextStream::Ok) {
            qtin.reset();
            qtin.resetStatus();
            QString garbage = "";
            garbage = qtin.readLine();
            qtout << "You must enter a number!" << endl;
        }
    } while (!(choice == 1 or choice == 2 or choice == 3));

    if (choice == 1) {
        return fileName;  //overwrite the file
    } else if (choice == 2) {
        return QString(); //user does not wish to continue
    } else {
        return getFileName(); // recursively attempt to get a good filename
    }
}
return fileName;  //file did not exist (hopefully)

}@

Output:
@Enter a filename: vitr
You entered: "vitr"

A file with that name already exists.
If you continue it will be over-written.
Do you wish to continue?

yes
no
to change filename

Enter 1, 2 or 3: 3

Enter a filename: You entered: ""

Enter a filename: vitry
You entered: "vitry"

A file with that name already exists.
If you continue it will be over-written.
Do you wish to continue?

yes
no
to change filename

Enter 1, 2 or 3: 3

Enter a filename: You entered: ""

Enter a filename: vitryu
You entered: "vitryu"

Read data from the file - watch for errors.@

Notice how on line 13 and on line 27 of the output the program doesn't wait for input. Yet on the initial call of the function it waits properly. I don't understand why it doesn't stop and wait for input on line 6 when the function is called recursively. Can anyone help me understand why it's doing this or help me fix it?

dbzhang800

Hi, when you press 1, 2 or 3, what you have pressed is

@
1\n, 2\n or 3\n
@

And you forget to discard the \n before you call readLine()

ScottCUSA

Thank you!

That makes a lot of sense. It just seems like that trailing '\n' should be discarded from the stream. How would you suggest I discard the '\n'?

readLine()?

This works, I was just wondering what you would suggest?