Qprocess: how to debug the full command send/used to start the process?

[Pl45m4]

@ademmler said in Qprocess: how to debug the full command send/used to start the process?:

I would like to debug/see the full command used to launch the process.

Hi,

qDebug() << proc->program << " " << proc->arguments();

returns

"/path/to/executable" ("option1", "option2")

And if you parse the QStringList with your args, you could create an output like the "real" command would look like.
Something like:

/path/to/executable -option1 -option2

[ademmler]

@Pl45m4 thx for the nice approach. But this is still a guess.
I have doubts that Process creates the proper command in my case.
Hence I want to see what is fired up there ...

Maybe somebody can point me to the right spot in the debugger ...

I am aware, that this peace of code is neither "not perfect QT" nor my real application.
It is a sketch to test and simulate my issue in a minimal version.

#include "mainwindow.h"
#include "ui_mainwindow.h"

using namespace std;

MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(parent)
    , ui(new Ui::MainWindow)
{
    ui->setupUi(this);

}

MainWindow::~MainWindow()
{
    delete ui;
}

void MainWindow::on_startButton_released()
{

    /* clear text report */
    ui->textEdit->clear();

    QString fileName = QFileDialog::getOpenFileName(this,
                                                    tr("Open Input Image"),
                                                    "~",
                                                    tr("Open file") + " (*.jpg *.jpeg *.tif *.tiff *.pdf)");
    QFile fi(fileName);

    if(fi.exists()) {
        slotDoPdfRaster(fileName);  // I know I should use a connect / emit here!
    } else {
        qDebug() << "No file opend";
    }


}


void MainWindow::slotDoPdfRaster(QString input) {

    QString inputFile = input;
    QString outputFile = input + ".tiff";
    QString report = input + ".devn";
    QDir rep;
    QDir in;
    QDir out;

    int ripResolutionLow = 50;

    ui->statusbar->showMessage("Start rip ...", 3);

    QString program = "pdfraster64";
    QStringList arguments;
        arguments << "-overprint" << "-overprintMode 3" << "-antialias yes" << "-aavector yes" << "-devn" << "-plateInfo" << "-dpi " + QString::number(ripResolutionLow) << "-devnstatus " + rep.toNativeSeparators(report) << in.toNativeSeparators(inputFile) << out.toNativeSeparators(outputFile);

    myProcess = new QProcess(this);
    qDebug() << "Rip program: " + program;
    qDebug() << "Rip arguments: " + arguments.join(" ");

    myProcess->start(program, arguments);

    /* show output */
    connect(myProcess, SIGNAL(readyReadStandardOutput()),this, SLOT(rightMessage()) );
    connect(myProcess, SIGNAL(readyReadStandardError()), this, SLOT(wrongMessage()) );

    ui->statusbar->showMessage("Idle ...", 0);
}

// show right message
void MainWindow::rightMessage()
{
    QByteArray strdata = myProcess->readAllStandardOutput();
    ui->textEdit->setTextColor(Qt::black);
    ui->textEdit->append(strdata);
}

// show wrong message
void MainWindow::wrongMessage()
{
    QByteArray strdata = myProcess->readAllStandardError();
    ui->textEdit->setTextColor(Qt::red);
    ui->textEdit->append(strdata);
}

[Christian Ehrlicher]

@ademmler said in Qprocess: how to debug the full command send/used to start the process?:

I have doubts that Process creates the proper command in my case.

What the debug output from @Pl45m4 show you is exactly what the process gets.

[ademmler]

@Christian-Ehrlicher

Ok - In the terminal - from qDebug() I see everything is fine.

I added as @Pl45m4 have said.
qDebug() << myProcess->program() << " " << myProcess->arguments();

Which brings this as a result:
"pdfraster64" ("-overprint", "-overprintMode 3", "-antialias yes", "-aavector yes", "-devn", "-plateInfo", "-dpi 50", "-devnstatus /Users/ademmler/Desktop/test4C.pdf.devn", "/Users/ademmler/Desktop/test4C.pdf", "/Users/ademmler/Desktop/test4C.pdf.tiff")

But the command (aka rip) is not started at all ...
And there is nothing on stdout or stderr ...

Again -how can I debug this than?

QString program = "pdfraster64";
QStringList arguments;
       arguments << "-overprint" << "-overprintMode 3" << "-antialias yes" << "-aavector yes" << "-devn" << "-plateInfo" << "-dpi " + QString::number(ripResolutionLow) << "-devnstatus " + rep.toNativeSeparators(report) << in.toNativeSeparators(inputFile) << out.toNativeSeparators(outputFile);

   myProcess = new QProcess(this);
   myProcess->start(program, arguments);
   qDebug() << myProcess->program() << " " << myProcess->arguments();

[SGaist]

@ademmler said in Qprocess: how to debug the full command send/used to start the process?:

arguments << "-overprint" << "-overprintMode 3" << "-antialias yes" << "-aavector yes" << "-devn" << "-plateInfo" << "-dpi " + QString::number(ripResolutionLow) << "-devnstatus " + rep.toNativeSeparators(report) << in.toNativeSeparators(inputFile) << out.toNativeSeparators(outputFile);

One issue here: the values of the option and their name if separated by a space shale be different items in the list. For example:

<< "-aavector" << "yes"

[ademmler]

@SGaist thx for pointing this out. That was the missing part.
Hence "all kind of spaces" are handled by Process - right?

What is your recommendation how to create such long/complex list of arguments?
Can I write it like this - or is there a better way of doing?

arguments << "-overprint" << "-overprintMode 3"
<< "-antialias" << yes"
<< "-aavector yes"
<< "-devn" << "-plateInfo"
<< "-dpi " + QString::number(ripResolutionLow)
<< "-devnstatus " + rep.toNativeSeparators(report)
<< in.toNativeSeparators(inputFile) << out.toNativeSeparators(outputFile);

[SGaist]

If I have long list of that kind of stuff, I put each entry on its own line.

[ademmler]

@SGaist thx - You mean - as I wrote it above.

There is comandline tools which syntax uses "="
like this: executable -option1 -option2=3
or even this: executable -option1 -option2 = 3

This would lead into: arguments << "-option1" << "-option2=" << "3";
Or into arguments << "-option1" << "-option2" << "=" << "3";

[ademmler]

@SGaist

I am so sorry - I marked the wrong answer as the correct one.
Does this Forum allow me to change this? I don't find the button for this ...

I Marked @SGaist answer as solution, because this made everything work.
I think it ia so important to understand that options and values need to be in separate quotes!
Bevor I could never get a Process running ... maybe a good note for the documentation.

[SGaist]

You can mark your thread as unsolved (done) and select a new answer.