QProcess redirecting output streams produces empty files!

basilikus

Hi there!

I'm trying to use QProcess to make a seperate process to use WinSCP. I have got the WinSCP side working using the windows process features, however I want to learn how to use QProcess.

The problem is, using QProcess does not output the process information in the cmd window (unlike the windows version) and I need to know what is said - so my plan is to redirect the output to a file so that it can be then read back in and output.

Anyway, below is the code which I use to make the process, however the files it produces are completely empty! (To clarify, the startString I know works, as I use it with the windows version so syntax and so forth is correct).

@void UploadProcess::makeQtProcess(MyGui* gui, QString dirAddr, QString device)
{
m_pGui = gui;

m_pProcess = new QProcess();

m_pProcess->setStandardOutputFile ("C:\outputfile.txt");
m_pProcess->setStandardErrorFile ("C:\errorfile.txt");

m_pProcess->setProcessChannelMode(QProcess::SeparateChannels);

QString startString = ""C:\Program Files\WinSCP\WinSCP.exe" /console /script="";
startString += dirAddr;
startString += "/Script.txt" /log="";
startString += dirAddr;
startString += "/";
startString += device;
startString += "/errorlog.log"";

m_pProcess->start(startString, QIODevice::ReadWrite);
m_pProcess->waitForFinished(-1);

    //Here I will put code to read back the information from the file.

if (m_pProcess->exitStatus() == QProcess::NormalExit)
{
gui->log("OK!");
}
else
{
gui->log("Failed!");
QString test = m_pProcess->errorString();
gui->log(test);
}

delete m_pProcess;
}@

Thanks for your help in advance!

Phil

joeuser

What happens when this executes, do you get "OK" or "Failed"? And have you tried QProcess::waitForStarted to ensure the process actually did start? In my limited experience with QProcess I've had better luck with the QProcess::start(const QString & program, const QStringList & arguments) method. You don't have to worry so much about the quotes around the program name and parameters. But I only work in Linux so I don't know if you really need those quotes.

cincirin

I don't tested, but try with "readAllStandardOutput":http://doc.qt.nokia.com/latest/qprocess.html#readAllStandardOutput