Unable to start linux process by Qt

[karankumar1609]

Hello everybody,

I have got stucked somewhere in my code.
I want to copy all the content from one directory to another, means copy data from source to destination.
I have written the below code, But its not working
And i dont know why

QScopedPointer<QProcess> my_process(new QProcess());
 
        QString source = parent_path;
        source.append(QDir::separator());
        source.append("*");
 
        QString destination = map_path;
        destination.append(QDir::separator());
 
        qDebug() << "Source : " << source;
        qDebug() << "Destination : " << destination;
 
        QStringList arguments;
        arguments << "-rf"
                  << source
                  << destination;
        my_process->start("cp", arguments);
 
        qDebug() << "Copied : " << my_process->waitForFinished();
        qDebug() << my_process->errorString();

QScopedPointer<QProcess> my_process(new QProcess());

        QString source = parent_path;
        source.append(QDir::separator());
        source.append("*");

        QString destination = map_path;
        destination.append(QDir::separator());

        qDebug() << "Source : " << source;
        qDebug() << "Destination : " << destination;

        QStringList arguments;
        arguments << "-rf"
                  << source
                  << destination;
        my_process->start("cp", arguments);

        qDebug() << "Copied : " << my_process->waitForFinished();
        qDebug() << my_process->errorString();

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Please tell me what is the problem in my code.,??????

[anda_skoa]

Your problem is most likely that your wildcards are not expanded. This is usually done by the shell, but you are not invoking the cp command through a shell but directly.

As far as I can see you have a couple of options:
1) create a list of file using QDir and then pass them to the cp command as input followed by the target dir
2) create a helper script that will internall pass its parameters to cp, expanding the in the process
3) call a shell and use its commandline arguments to run cp as a child command
4) copy in Qt by listing all files and calling QFile::copy() on each, probably doing all that in a thread in order not to block the main thread
5) create a small helper program in Qt that uses (4) in its main thread and is called by the main program through QProcess

Cheers,
_

[Lesiok]

"parent_path" is absolute or relative ? If relative what is current dir in application ?

[karankumar1609]

I have chnaged my code below

QScopedPointer<QProcess> my_process(new QProcess());
 
    QString source = parent_path;
    source.append(QDir::separator());
    // source.append("*");
 
    QString destination = map_path;
    destination.append(QDir::separator());
 
    qDebug() << "Source : " << source;
    qDebug() << "Destination : " << destination;
 
    QStringList arguments;
    arguments << "-rf"
    << source
    << destination;
    my_process->start("cp", arguments);
 
    qDebug() << "Copied : " << my_process->waitForFinished();
    qDebug() << my_process->errorString();

QScopedPointer<QProcess> my_process(new QProcess());
     
    QString source = parent_path;
    source.append(QDir::separator());
    // source.append("*");
     
    QString destination = map_path;
    destination.append(QDir::separator());
     
    qDebug() << "Source : " << source;
    qDebug() << "Destination : " << destination;
     
    QStringList arguments;
    arguments << "-rf"
    << source
    << destination;
    my_process->start("cp", arguments);
     
    qDebug() << "Copied : " << my_process->waitForFinished();
    qDebug() << my_process->errorString();

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Now it makes the data Directory in the destination directory.

Source = "/home/DATA/"
Destination = "/home/DATA_MAP/"

now it creates the DATA folder in my DATA_MAP folder.
I just want my data content in my DATA_MAP directory

---

Added after 12 minutes:

"parent_path" is the absolute path.

//////////////////////////////////
Following code wors for me

{
        QDir dir(parent_path);
 
        QStringList dirs = dir.entryList(QDir::Dirs | QDir::NoSymLinks | QDir::NoDotAndDotDot);
 
        foreach(QString directory, dirs) {
            QString source = parent_path;
            source.append(QDir::separator());
            source.append(directory);
            qDebug() << "Source : " << source;
 
            QString destination = map_path;
            destination.append(QDir::separator());
 
            QScopedPointer<QProcess> my_process(new QProcess());
 
            connect(this, SIGNAL(stopProcessing()), my_process.data(), SLOT(kill()), Qt::DirectConnection);
            QStringList arguments;
            arguments << "-rf"
                      << source
                      << destination;
 
            my_process->start("cp", arguments);
 
            qDebug() << "Copied : " << my_process->waitForFinished(-1);
        }

{
        QDir dir(parent_path);

        QStringList dirs = dir.entryList(QDir::Dirs | QDir::NoSymLinks | QDir::NoDotAndDotDot);

        foreach(QString directory, dirs) {
            QString source = parent_path;
            source.append(QDir::separator());
            source.append(directory);
            qDebug() << "Source : " << source;

            QString destination = map_path;
            destination.append(QDir::separator());

            QScopedPointer<QProcess> my_process(new QProcess());

            connect(this, SIGNAL(stopProcessing()), my_process.data(), SLOT(kill()), Qt::DirectConnection);
            QStringList arguments;
            arguments << "-rf"
                      << source
                      << destination;

            my_process->start("cp", arguments);

            qDebug() << "Copied : " << my_process->waitForFinished(-1);
        }

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