The QProcess class is used to start external programs and to communicate with them.
To start a process, pass the name and command line arguments of the program you want to run as arguments to start(). For example:
QObject *parent;
...
QString program = "./path/to/Qt/examples/widgets/analogclock";
QStringList arguments;
arguments << "-style" << "motif";
QProcess *myProcess = new QProcess(parent);
myProcess->start(program, arguments);