带重音符号的 QProcess 输入字符串

Question

I have two programs each with QProcess and I have a different behavior concerning the QProcess input with accentuated characters (more precisely I create a Qprocess to execute a dos copy command and the path takes accent).

The environnement of execution and development is Windows 10.

The first program is a simple prototype that I made to test if my code can work correctly.

Here is the prototype code I have, in which the copy works correctly, integrated in a simple main() function. The code is supposed to copy a file named sfx.exe into a path with accent F:\path_accentué and it indeed does the copy correctly.

#include <QCoreApplication>
#include <Qdebug>
#include <QObject>
#include <QProcess>

int main(int argc, char *argv[])
{
    QCoreApplication app(argc, argv);
    QProcess* processus = new QProcess();
    QStringList args; 
    QString path("F:\\path_accentué");
    
    args << "/C" << "copy" << "E:\\test\\sfx.exe" << path;
    processus->start("cmd.exe", args);  

    if (!processus->waitForStarted())
    {
        qDebug() << "Could not launch the process";
    }
    //processus->write(s.c_str());
    if (!processus->waitForFinished(-1))
    {
        qDebug() << "Finished";
    }
    delete processus;
    return app.exec();
}

However, when I integrate (literally copies and pasted without changing) this prototype within a bigger code project, my instance of QProcess does not recognize the accentuated path, as if accents are no more supported.

This is the part that I copy/paste in the bigger project and which I now execute via a button click in QT. And this time, the QProcess doesn't recognize the accentuated path (Instead it creates a file with name like this path_accentu� )

            QProcess* processus = new QProcess();
            QStringList args; 
            QString path("F:\\path_accentué");
            args << "/C" << "copy" << "E:\\test\\sfx.exe" << path;            processus->start("cmd.exe", args);  
            if (!processus->waitForStarted())
            {
                        qDebug() << "Could not launch the process";
            }
            //processus->write(s.c_str());
            if (!processus->waitForFinished(-1))
            {
                        qDebug() << "Finished";
            }

I do not find in the documentation a way to force the QProcess to recognize accentuated inputs. I would like to understand why the QProcess instance behaves differently when integrated within my bigger project. What may impact the behavior of the QProcess and leads it to treat differently the input in the second case?

Note: The QProcess is needed for more things but not only for the copy (such as getting feedback and percentage of operations). The copy is only to isolate the problem. In reality, I do much more things.

Answer 1

I tried to recreate your behaviour with Qt 5.15 and could create a file with accent with

• start("cmd",{args...})
• start("cmd /c args...")
• setNativeArguments("/c args...") + start("cmd")

Last one is recommended for "cmd" calls, see the remarks here:
https://doc.qt.io/qt-5/qprocess.html#start

The only thing, which did not work, because it deadlocks was

• setArguments({args...}) + start("cmd")

Demo here:
https://gist.github.com/elsamuko/59f110cf3a678beae9db27860f6305c9