Can't get QProcess output

[croscato]

Hi all!

I have the following code and can't figure out why I can't get the
QProcess output:

#include <QApplication>
#include <QProcess>
#include <QDebug>
 
int main(int argc, char **argv)
{
    QApplication application(argc, argv);
 
    QProcess proc;
 
    proc.start("c:\\windows\\system32\\cmd.exe", QIODevice::ReadWrite);
 
    if (proc.waitForStarted() == false) {
        qDebug() << "Error starting cmd.exe process";
        qDebug() << proc.errorString();
 
        return (-1);
    }
 
    // Show process output
    qDebug() << proc.readAllStandardOutput();
 
    proc.write("dir");
 
    qDebug() << proc.readAllStandardOutput();
 
    proc.close();
 
    return 0;
}

#include <QApplication>
#include <QProcess>
#include <QDebug>

int main(int argc, char **argv)
{
    QApplication application(argc, argv);

    QProcess proc;

    proc.start("c:\\windows\\system32\\cmd.exe", QIODevice::ReadWrite);

    if (proc.waitForStarted() == false) {
        qDebug() << "Error starting cmd.exe process";
        qDebug() << proc.errorString();

        return (-1);
    }

    // Show process output
    qDebug() << proc.readAllStandardOutput();

    proc.write("dir");

    qDebug() << proc.readAllStandardOutput();

    proc.close();

    return 0;
}

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Any ideas?

Thanks!

[boudie]

You need a slot connected to this signal:
void QProcess::readyReadStandardOutput ()** [signal]

[croscato]

I've changed the code to:

#include <QApplication>
#include <QProcess>
#include <QDebug>
 
int main(int argc, char **argv)
{
    QApplication application(argc, argv);
 
    QProcess proc;
 
    proc.start("c:\\windows\\system32\\cmd.exe", QIODevice::ReadWrite);
 
    if (proc.waitForStarted() == false) {
        qDebug() << "Error starting cmd.exe process";
        qDebug() << proc.errorString();
 
        return (-1);
    }
 
    // Show process output
    proc.waitForReadyRead();
    qDebug() << proc.readAllStandardOutput();
 
    proc.write("dir");
 
    proc.waitForBytesWritten();
    proc.waitForReadyRead();
 
    qDebug() << proc.readAllStandardOutput();
 
    proc.close();
 
    return 0;
}

#include <QApplication>
#include <QProcess>
#include <QDebug>

int main(int argc, char **argv)
{
    QApplication application(argc, argv);

    QProcess proc;

    proc.start("c:\\windows\\system32\\cmd.exe", QIODevice::ReadWrite);

    if (proc.waitForStarted() == false) {
        qDebug() << "Error starting cmd.exe process";
        qDebug() << proc.errorString();

        return (-1);
    }

    // Show process output
    proc.waitForReadyRead();
    qDebug() << proc.readAllStandardOutput();

    proc.write("dir");

    proc.waitForBytesWritten();
    proc.waitForReadyRead();

    qDebug() << proc.readAllStandardOutput();

    proc.close();

    return 0;
}

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and was able to get the this output:

Starting C:\Documents and Settings\Usuario\Meus documentos\Teste\debug\Teste.exe...
"Microsoft Windows XP [versÆo 5.1.2600]
(C) Copyright 1985-2001 Microsoft Corp.
 
C:\Documents and Settings\Usuario\Meus documentos\Teste\debug>" 
""

Starting C:\Documents and Settings\Usuario\Meus documentos\Teste\debug\Teste.exe...
"Microsoft Windows XP [versÆo 5.1.2600]
(C) Copyright 1985-2001 Microsoft Corp.

C:\Documents and Settings\Usuario\Meus documentos\Teste\debug>" 
""

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but the dir command output doesn't came out.

[squidge]

Depending on what you trying to do, you may wish to pass "/c dir" to cmd.exe as a parameter, which will give you the dir output.

[croscato]

fatjuicymole

Even with the "/c" parameter I can't get the dir output.

My intention is to send commands to the cmd.exe process and receive it's output.

There is a way of doing this?

Thanks....

[mattc]

It looks like you are getting an incomplete output from the process... maybe calling QProcess::waitForFinished() before QProcess::readAllStandardOutput can solve the problem.