Obtaining command line arguments in a Qt application

Question

The following snippet is from a little app I wrote using the Qt framework. The idea is that the app can be run in batch mode (i.e. called by a script) or can be run interact

Answer 1

Only in order to keep response up-to-date, Qt now provides a dedicated class for parsing command line:

http://doc.qt.io/qt-5/qcommandlineparser.html

P.S. : can only post this as response and not a comment; I'm sorry because the question was not really how to parse but how to access.

Answer 2

If you are writing a Console only application then you might want to consider using QCoreApplication instead of QApplicition. QCoreApplication is part of QtCore while QApplication is defined in QtGui, so you get an extra and unnecessary dependency.

Answer 3

If your argc and argv are good, I'm surprised this would be possible as QApplication::arguments() is extremely simple. Note the source code. Filtering the #ifdefs for Linux, it's just:

QStringList QCoreApplication::arguments()
{
    QStringList list;
    if (!self) {
        qWarning("QCoreApplication::arguments: Please instantiate the QApplication object first");
        return list;
    }
    const int ac = self->d_func()->argc;
    char ** const av = self->d_func()->argv;
    for (int a = 0; a < ac; ++a) {
        list << QString::fromLocal8Bit(av[a]);
    }
    return list;
}

That's all you've got. There's a Unicode caveat which I would not think would apply to Karmic:

"On Unix, this list is built from the argc and argv parameters passed to the constructor in the main() function. The string-data in argv is interpreted using QString::fromLocal8Bit(); hence it is not possible to pass, for example, Japanese command line arguments on a system that runs in a Latin1 locale. Most modern Unix systems do not have this limitation, as they are Unicode-based."

You might try a copy of that code against your argc and argv directly and see what happens.