QString program = "uptime";
             QStringList arguments;
             arguments << "| sed -e 's/.*p *//' -e 's/, l.*//' -e 's/  / /'";

             QProcess *myProcess = new QProcess(this);
        myProcess->startDetached(program, arguments);
        // qDebug() << myProcess->readAll();
        qDebug() << myProcess->readAllStandardOutput();
       // qDebug() << myProcess->exitCode();


Output:  11:20:48 up 5 days, 14:10, load average: 0.47, 0.57, 0.33