Checking if running as command-line (QCoreApplication) or GUI

Perdrix

Is it correct to write:

if (qApp)
{
     // Do gui stuff
}
else
{
    // Do command line stuff
}

Thanks, David

JonB

@Perdrix
I imagine that is a reasonable test if you want to do a Qt call, as in: "is there a QApplication object?"

A global pointer referring to the unique application object. It is equivalent to QCoreApplication::instance(), but cast as a QApplication pointer, so only valid when the unique application object is a QApplication.

However, are you intending to use single-source with two separate compilations/links, one for GUI and one for console? Because if you are thinking you can do just one compilation/link and decide at runtime whether to run as GUI or command line you are going to stall. Under Windows at least --- which ISTR you use --- an executable is linked as either "windows" (GUI) or "console" (command-line) and you are stuck with that at runtime.

Perdrix

@JonB I build a GUI application which instantiates a QApplication in its main(), and a completely different piece of code is used for the command line application which creates a QCoreApplication.

So I think that qApp will work in that case?

JonB

@Perdrix
It may depend on platform or what you mean by command line. Have you just tested linking your command line program with a piece of code which goes if (qApp) and verified the final executable is still a command-line/console application?

SGaist

@Perdrix said in Checking if running as command-line (QCoreApplication) or GUI:

@JonB I build a GUI application which instantiates a QApplication in its main(), and a completely different piece of code is used for the command line application which creates a QCoreApplication.

So I think that qApp will work in that case?

Hi,

Something is not clear: are you starting both the CLI and the GUI from the same main function ?