Correct way to quit a Qt program?

Question

How should I quit a Qt Program, e.g when loading a data file, and discovered file corruption, and user need to quit this app or re-initiate data file?

Should I:

Answer 1

if you need to close your application from main() you can use this code

int main(int argc, char *argv[]){
QApplication app(argc, argv);
...
if(!QSslSocket::supportsSsl()) return app.exit(0);
...
return app.exec();
}

The program will terminated if OpenSSL is not installed