Copy Directory Recusively

[hkothari]

So I'm writing a function to copy a file or directory recursively, if it's just a file It just uses QFile Copy, and it copies the file and it works, but when it's a directory, I get the directory Entry List and loop through it calling the copy method for each file, for some reason I keep getting put into some endless loop. Can anyone help me out with this? My code is below.

bool copy(QString sourceFilePath, QString destinationFilePath)
{
    QFile sourceFile(sourceFilePath);
    QFile destinationFile(destinationFilePath);
    QFileInfo sourceFileInfo(sourceFile);
    QFileInfo destinationFileInfo(destinationFile);
 
    if(sourceFileInfo.fileName() == "." || sourceFileInfo.fileName() == "..")
        return true;
 
    //If we're just copying a file and it's already readable.
    if(sourceFileInfo.isFile() && sourceFileInfo.isReadable())
    {
        if(destinationFileInfo.isFile() && destinationFile.isWritable())
        {
            //Warning, this deletes the file and replaces it.
            QString newFileName = destinationFile.fileName();
            destinationFile.remove();
            return sourceFile.copy(newFileName);
        }
        else if(destinationFileInfo.isDir() && destinationFileInfo.isWritable())
        {
            //We can use fileName in this case because we know that the FULL PATH is set above.
            QString newFileName = destinationFile.fileName();
            newFileName.append("/");
            //We have to use this to get JUST THE FILE NAME of the original file.
            newFileName.append(QFileInfo(sourceFile).fileName());
            return sourceFile.copy(newFileName);
        }
    }
    //If we're copying a directory, it'll have to be done recursively.
    else if(sourceFileInfo.isDir() && sourceFileInfo.isReadable())
    {
        qDebug() << "SFI Abs Path:" << sourceFileInfo.absolutePath();
        QDir sourceFileDir(sourceFileInfo.absolutePath());
        sourceFileDir.setFilter(QDir::AllDirs | QDir::Files | QDir::NoDotAndDotDot | QDir::Readable);
        QDir destinationFileDir(destinationFileInfo.absolutePath());
        qDebug() << "Mkdir output" << destinationFileDir.mkdir(sourceFileInfo.baseName());
        destinationFileDir.cd(sourceFileInfo.baseName());
 
        const QFileInfoList sourceFileDirInfoList = sourceFileDir.entryInfoList();
        for(int i = 0; i < sourceFileDirInfoList.size(); i++)
        {
            qDebug() << "Copy params: " << sourceFileDirInfoList[i].absoluteFilePath() << destinationFileDir.absolutePath();
            copy(sourceFileDirInfoList[i].absoluteFilePath(), destinationFileDir.absolutePath());
        }
 
        return true;
    }
 
    //If we end up here, something went wrong.
    return false;
}

bool copy(QString sourceFilePath, QString destinationFilePath)
{
    QFile sourceFile(sourceFilePath);
    QFile destinationFile(destinationFilePath);
    QFileInfo sourceFileInfo(sourceFile);
    QFileInfo destinationFileInfo(destinationFile);

    if(sourceFileInfo.fileName() == "." || sourceFileInfo.fileName() == "..")
        return true;

    //If we're just copying a file and it's already readable.
    if(sourceFileInfo.isFile() && sourceFileInfo.isReadable())
    {
        if(destinationFileInfo.isFile() && destinationFile.isWritable())
        {
            //Warning, this deletes the file and replaces it.
            QString newFileName = destinationFile.fileName();
            destinationFile.remove();
            return sourceFile.copy(newFileName);
        }
        else if(destinationFileInfo.isDir() && destinationFileInfo.isWritable())
        {
            //We can use fileName in this case because we know that the FULL PATH is set above.
            QString newFileName = destinationFile.fileName();
            newFileName.append("/");
            //We have to use this to get JUST THE FILE NAME of the original file.
            newFileName.append(QFileInfo(sourceFile).fileName());
            return sourceFile.copy(newFileName);
        }
    }
    //If we're copying a directory, it'll have to be done recursively.
    else if(sourceFileInfo.isDir() && sourceFileInfo.isReadable())
    {
        qDebug() << "SFI Abs Path:" << sourceFileInfo.absolutePath();
        QDir sourceFileDir(sourceFileInfo.absolutePath());
        sourceFileDir.setFilter(QDir::AllDirs | QDir::Files | QDir::NoDotAndDotDot | QDir::Readable);
        QDir destinationFileDir(destinationFileInfo.absolutePath());
        qDebug() << "Mkdir output" << destinationFileDir.mkdir(sourceFileInfo.baseName());
        destinationFileDir.cd(sourceFileInfo.baseName());

        const QFileInfoList sourceFileDirInfoList = sourceFileDir.entryInfoList();
        for(int i = 0; i < sourceFileDirInfoList.size(); i++)
        {
            qDebug() << "Copy params: " << sourceFileDirInfoList[i].absoluteFilePath() << destinationFileDir.absolutePath();
            copy(sourceFileDirInfoList[i].absoluteFilePath(), destinationFileDir.absolutePath());
        }

        return true;
    }

    //If we end up here, something went wrong.
    return false;
}

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[yogeshgokul]

Use this function:

void copyFolder(QString sourceFolder, QString destFolder)
{   
	QDir sourceDir(sourceFolder);
	if(!sourceDir.exists())
		return;
	QDir destDir(destFolder);
	if(!destDir.exists())
	{
		destDir.mkdir(destFolder);
	}
	QStringList files = sourceDir.entryList(QDir::Files);
	for(int i = 0; i< files.count(); i++)
	{
		QString srcName = sourceFolder + "/" + files[i];
		QString destName = destFolder + "/" + files[i];
		QFile::copy(srcName, destName);
	}
	files.clear();
	files = sourceDir.entryList(QDir::AllDirs | QDir::NoDotAndDotDot);
	for(int i = 0; i< files.count(); i++)
	{
		QString srcName = sourceFolder + "/" + files[i];
		QString destName = destFolder + "/" + files[i];
		copyFolder(srcName, destName);
	}
}

void copyFolder(QString sourceFolder, QString destFolder)
{   
	QDir sourceDir(sourceFolder);
	if(!sourceDir.exists())
		return;
	QDir destDir(destFolder);
	if(!destDir.exists())
	{
		destDir.mkdir(destFolder);
	}
	QStringList files = sourceDir.entryList(QDir::Files);
	for(int i = 0; i< files.count(); i++)
	{
		QString srcName = sourceFolder + "/" + files[i];
		QString destName = destFolder + "/" + files[i];
		QFile::copy(srcName, destName);
	}
	files.clear();
	files = sourceDir.entryList(QDir::AllDirs | QDir::NoDotAndDotDot);
	for(int i = 0; i< files.count(); i++)
	{
		QString srcName = sourceFolder + "/" + files[i];
		QString destName = destFolder + "/" + files[i];
		copyFolder(srcName, destName);
	}
}

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[hkothari]

Thank you very much, that seems to work.

[numbat]

Here's a way to do it with iteration rather than recursion. None of these solutions avoid the infinite recursion problem.

void copyFolder(const QString& sourceFolder,const QString& destFolder)
{
    QQueue< QPair<QString, QString> > queue;
 
    queue.enqueue(qMakePair(sourceFolder, destFolder));
 
    while (!queue.isEmpty())
    {
        QPair<QString, QString> pair = queue.dequeue();
        QDir sourceDir(pair.first);
        QDir destDir(pair.second);
 
        if(!sourceDir.exists())
            continue;
 
        if(!destDir.exists())
            destDir.mkpath(pair.second);
 
        QStringList files = sourceDir.entryList(QDir::Files);
        for(int i = 0; i < files.count(); i++)
        {
            QString srcName = pair.first + "/" + files.at(i);
            QString destName = pair.second + "/" + files.at(i);
            QFile::copy(srcName, destName);
        }
 
        QStringList dirs = sourceDir.entryList(QDir::AllDirs | QDir::NoDotAndDotDot);
        for(int i = 0; i < dirs.count(); i++)
        {
            QString srcName = pair.first + "/" + dirs.at(i);
            QString destName = pair.second + "/" + dirs.at(i);
            queue.enqueue(qMakePair(srcName, destName));
        }
   }
}

void copyFolder(const QString& sourceFolder,const QString& destFolder)
{
    QQueue< QPair<QString, QString> > queue;

    queue.enqueue(qMakePair(sourceFolder, destFolder));

    while (!queue.isEmpty())
    {
        QPair<QString, QString> pair = queue.dequeue();
        QDir sourceDir(pair.first);
        QDir destDir(pair.second);

        if(!sourceDir.exists())
            continue;

        if(!destDir.exists())
            destDir.mkpath(pair.second);

        QStringList files = sourceDir.entryList(QDir::Files);
        for(int i = 0; i < files.count(); i++)
        {
            QString srcName = pair.first + "/" + files.at(i);
            QString destName = pair.second + "/" + files.at(i);
            QFile::copy(srcName, destName);
        }

        QStringList dirs = sourceDir.entryList(QDir::AllDirs | QDir::NoDotAndDotDot);
        for(int i = 0; i < dirs.count(); i++)
        {
            QString srcName = pair.first + "/" + dirs.at(i);
            QString destName = pair.second + "/" + dirs.at(i);
            queue.enqueue(qMakePair(srcName, destName));
        }
   }
}

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[Lykurg]

I'd prefer recursive calling instead of cashing the paths in a queue, but anyway, use QDir::separator() instead of the slash in case you want cross platform compatibility.