QString program = "df";
            QStringList arguments;
            arguments << "-h";

            QProcess *myProcess = new QProcess(this);
            myProcess->setReadChannelMode(QProcess::MergedChannels);
            myProcess->start(program, arguments);

             if (!myProcess->waitForFinished())
            {
                  qDebug() << "Make failed:" << myProcess->errorString();
              }
              else
             {
                  qDebug() << "Make output:" << myProcess->readAll();
                  ui->textBrowser->setText(myProcess->readAll());
         }


*********************
Debug Output:
Make output: "Filesystem                Size      Used Available Use% Mounted on
rootfs                  227.9M    150.4M     73.3M  67% /
ubi0:rootfs             227.9M    150.4M     73.3M  67% /
tmpfs                     1.0M    380.0k    644.0k  37% /tmp
tmpfs                   256.0k     92.0k    164.0k  36% /var/run
none                     10.0M     84.0k      9.9M   1% /dev
tmpfs                    64.0M      4.0k     64.0M   0% /dev/shm
/dev/mmcblk0p2            2.0G    854.6M      1.0G  45% /home
/home/opt                 2.0G    854.6M      1.0G  45% /opt
/opt/pymaemo/usr/lib/python2.5
                          2.0G    854.6M      1.0G  45% /usr/lib/python2.5
/opt/pymaemo/usr/share/pyshared
                          2.0G    854.6M      1.0G  45% /usr/share/pyshared
/opt/pymaemo/usr/lib/pyshared
                          2.0G    854.6M      1.0G  45% /usr/lib/pyshared
/opt/pymaemo/usr/share/python-support
                          2.0G    854.6M      1.0G  45% /usr/share/python-support
/opt/pymaemo/usr/lib/python-support
                          2.0G    854.6M      1.0G  45% /usr/lib/python-support
/dev/mmcblk0p1           27.0G      6.9G     20.1G  26% /home/user/MyDocs
/dev/mmcblk1p1            5.5G     39.6M      5.4G   1% /media/mmc1
"