How To Redirect The Console Output To A Text Browser/pop Up

[deekayt]

Probably that is the problem.I am sure it is not behaving as a normal .exe
I tried to run it through a bat (stego.bat)file in which i wrote the command cjpeg

The code was as

void steg::stego()
{
  QProcess *P1 =new QProcess ;
  /*char steg_comand[]= "-steg";     
  char q_comand[]=     "-q";
  
  QStringList s2;   
      
  s2 << steg_comand << "coded.txt" << q_comand << ui.compressionspinBox->text() << ui.imagelineEdit->text() << ui.jpeglineEdit ->text() ;
 
  P1->setReadChannelMode(QProcess::MergedChannels);
 
  P1->start( QString("cjpeg.exe"),s2 ); */
 
 P1->start(QString("stego.bat")); OR    P1->startDetached(QString("stego.bat")); 
 P1->waitForFinished();
 QString result_hide=  P1->readAllStandardOutput();
 
QFile file1;
 //QDir::setCurrent("E:");
    file1.setFileName("hide_error.html");  
    file1.open(QIODevice::WriteOnly);       
 
     QTextStream out(&file1);
     out <<  result_hide;  
     file1.close();
     //ui.textBrowser->clear();
  QUrl myurl2;
  myurl2=QUrl::fromLocalFile( "hide_error.html" ) ;
  ui.textBrowser->setSource(myurl2);  
  }

void steg::stego()
{
  QProcess *P1 =new QProcess ;
  /*char steg_comand[]= "-steg";     
  char q_comand[]=     "-q";
  
  QStringList s2;   
      
  s2 << steg_comand << "coded.txt" << q_comand << ui.compressionspinBox->text() << ui.imagelineEdit->text() << ui.jpeglineEdit ->text() ;

  P1->setReadChannelMode(QProcess::MergedChannels);

  P1->start( QString("cjpeg.exe"),s2 ); */
 
 P1->start(QString("stego.bat")); OR    P1->startDetached(QString("stego.bat")); 
 P1->waitForFinished();
 QString result_hide=  P1->readAllStandardOutput();

QFile file1;
 //QDir::setCurrent("E:");
    file1.setFileName("hide_error.html");  
    file1.open(QIODevice::WriteOnly);       

     QTextStream out(&file1);
     out <<  result_hide;  
     file1.close();
     //ui.textBrowser->clear();
  QUrl myurl2;
  myurl2=QUrl::fromLocalFile( "hide_error.html" ) ;
  ui.textBrowser->setSource(myurl2);  
  }

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When I used P1->start(QString("stego.bat)); the dos screen appeared and I found the error message(as it should have come) and then the screen disappeared since I have not put any code to stop that. It means there was output to console as I want it . But it didnot get captured to QString result_all . How can I capture it (but keeping only start()) and then redirect to textbrowser.

when I used P1->startDetached (QString("stego.bat)); as expected no screen appeared and the cjpeg command did not run. And interestingly i get the out put as

C:\Qt\4.1.3\stegform1\release>cjpeg

where "C:\Qt\4.1.3\stegform1\release" is the current directory and cjpeg is thecommand written in stego.bat. If i could simulate "enter" after cjpeg in stego.bat perhaps it would have executed.
Can u suggest a way out. I cannot change cjpeg.exe.

[jacek]

If you have access to cjpeg sources, you could check why it behaves like that and maybe you will find a way to fool it.

[deekayt]

changing cjpeg.exe is out of question
how can i have Qprocess -> start() and still read the std out puts.that perhaps may solve the problem.also with Qprocess-> start() how to keep the console screen on instead of closing on its own.Like we useto stop the screen with getchar();

[jacek]

changing cjpeg.exe is out of question

I didn't write anything about changing cjpeg.exe.

[deekayt]

Dear JACEK
my Query is not still answered.Do tell how to circumvent this problem.
That is the last thing left in my project .
I know you can get me out of this.
Thanks

[jacek]

my Query is not still answered.Do tell how to circumvent this problem.

I've already told you: take a look at cjpeg sources and see why it behaves like that, then you can look for a solution.

[deekayt]

how can i have Qprocess -> start() and still read the std out puts.that perhaps may solve the problem.also with Qprocess-> start() how to keep the console screen on instead of closing on its own.Like we useto stop the screen with getchar();

[jacek]

I've found some cjpeg.exe in the Internet (here) and tested it with Qt 4.1.5 on windows and I had no problem to capture its output.

So either:

• you have some other cjpeg.exe that behaves in a different way,
• your cjpeg is compiled in a weird way,
• there's something wrong with your program.

[deekayt]

JACEK
I must thank you for all the pains you would have taken to look for CJPEG.EXE on the net and then testing it.
Infact this CJPEG.EXE is from Independent JPEG group ( VERSION 6) .The same program ( VERSION 4) has been modified for data hiding in JPEG images. ANd some more switches have been provided.
Now instead of just converting a PPM file to JPEG one can add a data file with -steg switch in the JPEG file so formed.( This modification perhaps has not been done in VERSION 6 )

cjpeg -steg <filename> image.ppm image2.jpg

is the way it works.
Now there is a limit to the amount of data one can hide in the JPEG file. When all the filenames are OK and data to be hidden is not exceeding there is no message meaning the thing has worked fine.
But if the data is too much to be loaded or <filename> or image.ppm is missing then the error message come. Now this happens on the comd prompt and not through my program.
I couldhave attached the zipped file but it is 2 mb.I am sending it in email. Please have a look at it.You have brought me till here.Thanks

[deekayt]

At Which Email Should I Send 2 Mb Zip File.

[jacek]

At Which Email Should I Send 2 Mb Zip File.

Don't send me your program, instead attach only the cjpeg.exe and I will see if I can make it work.

There rest is your assignment and you should do it yourself. All I can do is to try to give you some advises.

[deekayt]

I am attaching the cjpeg.exe alongwith
The command line utility is

cjpeg -steg <filename1> filename2.ppm filename3.jpg

where in the filename2.ppm changes to filename3.jpg ( that is it is compressed) and while doing so filename1( could be any type of file) gets embedded in the filename3.jpg.

Error messages are given when files donot exist or the filename1 is too large to be hidden ( it should be lesser than 10 % of the filename2.ppm size )
If everything is alright then the data is hidden and no message is generated at all.