problem with System()

AlvaroS

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AlvaroS

@jsulm In a terminal if I write
./princi 0 747.37 427.68 0 844.37 42.54 prueba_princi.bmp 0 0 +
in /home/user1/ directory it runs good

@jsulm said:

@AlvaroS Then try what @mrjj suggested

okey, it gives me UnknowError.... http://doc.qt.io/qt-5/qprocess.html#ProcessError-enum

mrjj

@AlvaroS

well you can use
qDebug() "qproc: " << myProcess->error();

and check the code in
http://doc.qt.io/qt-5/qprocess.html#ProcessError-enum

AlvaroS

@mrjj Yes thanks!! See my last post. Thanks again. It gives me Unknow error...

mrjj

@AlvaroS

" This is the default return value of error()."

You do call it AFTER u call
myProcess->start(program,arguments); ?

AlvaroS

@mrjj Yes:

    myProcess->start(program, arguments);

    QProcess::ProcessError error = myProcess->error();

mrjj

@AlvaroS
hmm really odd then
it should say FailedToStart

Just to be 100% clear.

princi is never run ?

AlvaroS

@mrjj said:

@AlvaroS
hmm really odd then
it should say FailedToStart

Just to be 100% clear.

princi is never run ?

okey look.
if I write:

    myProcess->start(program, arguments);

    myProcess->waitForFinished(3000);

    QProcess::ProcessError error = myProcess->error();

Now error says:
QProcess::Crashed The process crashed some time after starting successfully.

mrjj

so it sounds like your princi do run but it crashes?

oh. sorry my bad. start is async so calling error right after was
not correct.

waitForFinished fixed that.

AlvaroS

@mrjj Yes... I think so...
How should I pass the arguments?

the arguments of princi are:

0 wps.front().x() wps.front().y() 0 wps.back().x() wps.front().y() prueba_princi.bmp 0 0 +

so my QStringList arguments is:

 QStringList arguments;
arguments << "0" << QString::number(wps.front().x()) << QString::number(wps.front().y()) << "0" << QString::number(wps.back().x()) << QString::number(wps.back().y()) << "prueba_princi.bmp" << "0" << "0" << "+" ;

mrjj

it seems fine
You should look inside princi for how it
reads it. it must be that part that is crashing ?

AlvaroS

@mrjj yes, but it really rare that if I run from terminal princi runs good...

AlvaroS

@mrjj And if I write:

system ("./princi 0 5 10 0 7 8 prueba_princi.bmp 0 0 +")
where 5,10,7 and 8 are wps.front,wps.back....
it runs well...

SGaist

What is that + sign doing as parameter ?

AlvaroS

@SGaist + is just and argument that i have to pass to princi

mrjj

@AlvaroS
well you must debug it then.
Try to qDebug inside princi what you read and compare that to what u read for
system ("./princi 0 5 10 0 7 8 prueba_princi.bmp 0 0 +")

Sadly We cannot guess why you crash from the code shown.

Also you dump the arguments to qDebug before u
call start, just to see what u are sending also.

and then take it from there.