[SOLVED] Download and Update a Qt Program on Linux

[CKurdu]

Hi everybody

I am trying the programming an update system for my qt program.

void MainWindow::updateDownloaded()
{
    #ifdef Q_WS_WIN
        QString fileName = QString("Updater-%1.exe").arg(VERSION);
    #endif
    #ifdef Q_OS_LINUX
        QString fileName = QString("Updater-%1.run").arg(VERSION);
    #endif;
    qDebug()<<"One update has been downloaded."<<endl;
    QFile file(fileName);
    if(file.open(QIODevice::WriteOnly))
    {
        file.write(this->downloader->downloadedData());
        #ifdef Q_OS_LINUX
            file.setPermissions(QFile::ExeOther|QFile::ExeOwner|QFile::ExeGroup|QFile::ReadUser|QFile::ReadOther|QFile::ReadGroup|QFile::ReadOwner|QFile::WriteUser);
        #endif;
        QProcess *process = new QProcess(this);
        qDebug() << QDir::currentPath()+QDir::separator()+fileName<<endl;
        connect(process,SIGNAL(error(QProcess::ProcessError)),this,SLOT(processErrorOccured(QProcess::ProcessError)));
        process->start(QDir::currentPath()+QDir::separator()+fileName);

    }
    delete this->downloader;

}

void MainWindow::processErrorOccured(QProcess::ProcessError err)
{
    switch(err)
    {
    case QProcess::FailedToStart:
        qDebug()<<"Failed to start"<<endl;
        break;
    case QProcess::Crashed:
        qDebug()<<"Creached"<<endl;
        break;
    case QProcess::Timedout:
        qDebug()<<"Timedout"<<endl;
        break;
    case QProcess::WriteError:
        qDebug()<<"WriteError"<<endl;
        break;
    case QProcess::ReadError:
        qDebug()<<"ReadError"<<endl;
        break;
    case QProcess::UnknownError:
        qDebug()<<"UnknowError"<<endl;
        break;
    }

}

But I get "failed to start" error. When I try to run downloaded updater by clicking, program starts as expected. Program has right permissions to execute.

[mchinand]

Maybe close the file after you write to it and before you try to start the QProcess.

[CKurdu]

Thank you mchinand. It works now.

[mchinand]

Great! Just curious, how do you create the updater executables? Are they binary diffs between the versions?

[CKurdu]

Actually dll files and modules that changed or removed and update script. I will combine all of them in a single executable.