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

[deekayt]

I am running an external process ( dos exe file runnable on command prompt) through Q process
I need to capture the error messages and either display them in the text browser ( which is static in my form) or make custom made message (depending on what the exe program has given ) and then display them in the textbrowser/popUP

Earlier I was able to do so in qt3.3.4 on linux with the following code

system ( "/root/stego/encrypt.sh >&  /root/stego/error.txt" );  
    textBrowser->clear();
    textBrowser->setSource( "/root/stego/error.txt") ;

system ( "/root/stego/encrypt.sh >&  /root/stego/error.txt" );  
    textBrowser->clear();
    textBrowser->setSource( "/root/stego/error.txt") ;

To copy to clipboard, switch view to plain text mode 

where I was running the command prompt command through a script file ( encrypt.sh in above case) and redirecting the screen output to error .txt and then redirecting it to text browser.

Now in qt 4 ( windows) I am using the Qprocess as under

void steg::encrypt()
{
 char encrypt_comand[]= "-e";
 char key_comand[]= "-k=";
 QStringList s3;  
 s3 << encrypt_comand << ui.datalineEdit->text() << "coded.txt" << ( key_comand + ui.passphraselineEdit->text() );
 QProcess::startDetached( QString("burp.exe"),s3 ); 
 
}

void steg::encrypt()
{
 char encrypt_comand[]= "-e";
 char key_comand[]= "-k=";
 QStringList s3;  
 s3 << encrypt_comand << ui.datalineEdit->text() << "coded.txt" << ( key_comand + ui.passphraselineEdit->text() );
 QProcess::startDetached( QString("burp.exe"),s3 ); 

}

To copy to clipboard, switch view to plain text mode 

The burp.exe is command prompt command and gives the ok/error messages on the screen ( on console). How to direct the same to a text file.Then compare and show a custom message say in a text browser or I can even resort to pop message( why not?/let me improve with qt 4)

Thanks in advance for the guidance.

[jacek]

You can use QProcess::readAllStandardOutput() and QProcess::readAllStandardError() to read the data. QProcess::readyReadStandardError() and QProcess::readyReadStandardOutput () signals will be emitted when the data is available.

Of course you will have to use QProcess instance, instead of QProcess::startDetached().

[deekayt]

I have tried the following

void steg::encrypt()
{
 QProcess *P =new QProcess ;
 char encrypt_comand[]= "-e";
 char key_comand[]= "-k=";
 QStringList s3;  
 s3 << encrypt_comand << ui.datalineEdit->text() << "coded.txt" << ( key_comand + ui.passphraselineEdit->text() );
  P->startDetached( QString("burp.exe"),s3 );  
  QString result_all = P->readAllStandardOutput();
 //QMessageBox::about(this, tr("JPSTEGO"),tr(result_all.toAscii()));
 
 
QFile file;
 
    file.setFileName("showjpegfile.txt");  
    file.open(QIODevice::WriteOnly);       
 
     QTextStream out(&file);
     out <<  result_all.toAscii();  
 
ui.textEdit->insertPlainText(result_all);
 
}

void steg::encrypt()
{
 QProcess *P =new QProcess ;
 char encrypt_comand[]= "-e";
 char key_comand[]= "-k=";
 QStringList s3;  
 s3 << encrypt_comand << ui.datalineEdit->text() << "coded.txt" << ( key_comand + ui.passphraselineEdit->text() );
  P->startDetached( QString("burp.exe"),s3 );  
  QString result_all = P->readAllStandardOutput();
 //QMessageBox::about(this, tr("JPSTEGO"),tr(result_all.toAscii()));
   

QFile file;
    
    file.setFileName("showjpegfile.txt");  
    file.open(QIODevice::WriteOnly);       

     QTextStream out(&file);
     out <<  result_all.toAscii();  

ui.textEdit->insertPlainText(result_all);

}

To copy to clipboard, switch view to plain text mode 

First I tried to take the Qstring and display in the message box. Nothing happened . Message box comes up but no message is there. Though burp .exe gets executed and gives msg everytime on the command prompt.
Then I tried to redirect the console output to a file and put in a textedit( not a clean way)but it also didnot work.

I am only sure that burp.exe gets executed sinceI find files encrypted as required.I am also sure that some console output always comes. But after that I am not able to find out the problem.

[jacek]

P->startDetached( QString("burp.exe"),s3 );
QString result_all = P->readAllStandardOutput();

I've already told you two times, that QProcess::startDetached() is a static method. There is no sense in invoking it on an object.

Try:

P->start( "burp.exe", s3 );
P->waitForFinished();
QString result_all = P->readAllStandardOutput();

P->start( "burp.exe", s3 );
P->waitForFinished();
QString result_all = P->readAllStandardOutput();

To copy to clipboard, switch view to plain text mode 

and make sure that this "burp" thing writes to standard output, not standard error stream.

[deekayt]

My requirement is to get the console output to the text browser.( Message box and text edit)
I have tried the following code

void steg::encrypt()
{
 QProcess *P =new QProcess ;
 char encrypt_comand[]= "-e";
 char key_comand[]= "-k=";
 QStringList s3;  
 s3 << encrypt_comand << ui.datalineEdit->text() << "coded.txt" << ( key_comand + ui.passphraselineEdit->text() );
  P->start( QString("burp.exe"),s3 ); 
  P->waitForFinished();
  QString result_all=  P->readAllStandardOutput();
  ui.textBrowser->setSource( result_all);
}

void steg::encrypt()
{
 QProcess *P =new QProcess ;
 char encrypt_comand[]= "-e";
 char key_comand[]= "-k=";
 QStringList s3;  
 s3 << encrypt_comand << ui.datalineEdit->text() << "coded.txt" << ( key_comand + ui.passphraselineEdit->text() );
  P->start( QString("burp.exe"),s3 ); 
  P->waitForFinished();
  QString result_all=  P->readAllStandardOutput();
  ui.textBrowser->setSource( result_all);
}

To copy to clipboard, switch view to plain text mode 

But it did not work . Then I tried to write the Qstring result_all to a file and then see the file manually.The file gets created but nothing is written to file. That means nothing is in QString result_ all . Then I tried to see that the Qstring result_all is put in the tetxEdit ( since setText is there and perhaps Url thing might be giving problem in TextBrowser) But that also did not work. Those codes are down below

QFile file;
    file.setFileName("showjpegfile.txt");  
    file.open(QIODevice::WriteOnly);       
     QTextStream out(&file);
     out <<  result_all;  //NOTHING HAPPENED
 
 ui.textEdit->textCursor().insertText(result_all); //NOTHING HAPPENED

QFile file;
    file.setFileName("showjpegfile.txt");  
    file.open(QIODevice::WriteOnly);       
     QTextStream out(&file);
     out <<  result_all;  //NOTHING HAPPENED

 ui.textEdit->textCursor().insertText(result_all); //NOTHING HAPPENED

To copy to clipboard, switch view to plain text mode 

How can I try to put in the message box
I tried the code below.But it doesnot work.

QMessageBox::about(this, tr("About JPSTEGO"),
            tr("<p>The <b>JPSTEGO</b> is a  data  hiding and extraction software"
               "forhiding data while converting image files to JPEG format",
               +result_all));

QMessageBox::about(this, tr("About JPSTEGO"),
            tr("<p>The <b>JPSTEGO</b> is a  data  hiding and extraction software"
               "forhiding data while converting image files to JPEG format",
               +result_all));

To copy to clipboard, switch view to plain text mode 

[jacek]

Does P->waitForFinished() return true? Does "burb.exe" write data to standard output?

[deekayt]

While I was awaiting your reply I tinkered with the code and was able to figure out the error.
In fact burp.exe was writing to standard error channel instead of standard output. I then further improved it to merge the channels and the code is as
below

void steg::encrypt()
{
 QProcess *P =new QProcess ;
 char encrypt_comand[]= "-e";
 char key_comand[]= "-k=";
 QStringList s3;  
 s3 << encrypt_comand << ui.datalineEdit->text() << "coded.txt" << ( key_comand + ui.passphraselineEdit->text() );
  P->setReadChannelMode(QProcess::MergedChannels); 
P->start( QString("burp.exe"),s3 ); 
 P->waitForFinished();
 QString result_all=  P->readAllStandardOutput();
 QFile file;
 //QDir::setCurrent("E:");
    file.setFileName("encrypt_error.html");  
    file.open(QIODevice::WriteOnly);       
 
     QTextStream out(&file);
     out <<  result_all;  
     file.close();
  ui.textBrowser->clear();
  QUrl myurl1;
  myurl1=QUrl::fromLocalFile( "encrypt_error.html" ) ;
  ui.textBrowser->setSource(myurl1);  
 
}

void steg::encrypt()
{
 QProcess *P =new QProcess ;
 char encrypt_comand[]= "-e";
 char key_comand[]= "-k=";
 QStringList s3;  
 s3 << encrypt_comand << ui.datalineEdit->text() << "coded.txt" << ( key_comand + ui.passphraselineEdit->text() );
  P->setReadChannelMode(QProcess::MergedChannels); 
P->start( QString("burp.exe"),s3 ); 
 P->waitForFinished();
 QString result_all=  P->readAllStandardOutput();
 QFile file;
 //QDir::setCurrent("E:");
    file.setFileName("encrypt_error.html");  
    file.open(QIODevice::WriteOnly);       

     QTextStream out(&file);
     out <<  result_all;  
     file.close();
  ui.textBrowser->clear();
  QUrl myurl1;
  myurl1=QUrl::fromLocalFile( "encrypt_error.html" ) ;
  ui.textBrowser->setSource(myurl1);  
  
}

To copy to clipboard, switch view to plain text mode 

1. Now I am able to get whatever is the output to the textBrowser . But I believe there would be better way without getting through the file thing. Could you suggest a better method.

2. Moreover I want to output to textbrowser the messages defined by me after comparing what is the output of these exe processes. Is there a method in QT to compare the message, or look for a string and then make own message or delete a part of the message or append a part from the user side and then get it to the textbrowser.

[jacek]

Now I am able to get whatever is the output to the textBrowser . But I believe there would be better way without getting through the file thing. Could you suggest a better method.

QTextEdit::setPlainText() or QTextEdit::setHtml()

Moreover I want to output to textbrowser the messages defined by me after comparing what is the output of these exe processes. Is there a method in QT to compare the message, or look for a string and then make own message or delete a part of the message or append a part from the user side and then get it to the textbrowser.

QRegExp and QString::find()

[deekayt]

Now I am facing a peculiar problem .
After resolving the issue of burp.exe with the following code

void steg::encrypt()
{
 QProcess *P =new QProcess ;
 char encrypt_comand[]= "-e";
 char key_comand[]= "-k=";
 QStringList s3;  
 s3 << encrypt_comand << ui.datalineEdit->text() << "coded.txt" << ( key_comand + ui.passphraselineEdit->text() );
  P->setReadChannelMode(QProcess::MergedChannels); 
P->start( QString("burp.exe"),s3 ); 
 P->waitForFinished();
 QString result_all=  P->readAllStandardOutput();
 QFile file;
 //QDir::setCurrent("E:");
    file.setFileName("encrypt_error.html");  
    file.open(QIODevice::WriteOnly);     
     QTextStream out(&file);
     out <<  result_all;  
     file.close();
  ui.textBrowser->clear();
  QUrl myurl1;
  myurl1=QUrl::fromLocalFile( "encrypt_error.html" ) ;
  ui.textBrowser->setSource(myurl1);  
}

void steg::encrypt()
{
 QProcess *P =new QProcess ;
 char encrypt_comand[]= "-e";
 char key_comand[]= "-k=";
 QStringList s3;  
 s3 << encrypt_comand << ui.datalineEdit->text() << "coded.txt" << ( key_comand + ui.passphraselineEdit->text() );
  P->setReadChannelMode(QProcess::MergedChannels); 
P->start( QString("burp.exe"),s3 ); 
 P->waitForFinished();
 QString result_all=  P->readAllStandardOutput();
 QFile file;
 //QDir::setCurrent("E:");
    file.setFileName("encrypt_error.html");  
    file.open(QIODevice::WriteOnly);     
     QTextStream out(&file);
     out <<  result_all;  
     file.close();
  ui.textBrowser->clear();
  QUrl myurl1;
  myurl1=QUrl::fromLocalFile( "encrypt_error.html" ) ;
  ui.textBrowser->setSource(myurl1);  
}

To copy to clipboard, switch view to plain text mode 

I had to use it for another exe program that is cjpeg.exe. I used the following code

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->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();
 
  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->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();
     
  QUrl myurl2;
  myurl2=QUrl::fromLocalFile( "hide_error.html" ) ;
  ui.textBrowser->setSource(myurl2);  
  }

To copy to clipboard, switch view to plain text mode 

The above code is suppose to convert a .ppm(image file) to jpeg while hiding a text file in it. If all is ok then no output is thrown on the console else one gets an error message.
I deliberately choose parameters to generate the error message but i get blank hide_error.html(which do get created everytime). cjpeg.exe does work since when all parameters are ok I get the jpeg file made. When I run the cjpeg command on command prompt or through a .bat file i get the messages on the console.
In order to verify the code I just replaced cjpeg.exe with burp.exe and i immediately got the error message of burp in my text browser. I know the problem is with cjpeg.exe.But the same thing is fine on command prompt. In fact it is runing even through this code since i got the desired file ( as output ) . I donot know what is the problem.
Could u tell please me How to debug and resolve??
I have been trying forlast three days, but no luck.

[jacek]

I know the problem is with cjpeg.exe.But the same thing is fine on command prompt. In fact it is runing even through this code since i got the desired file ( as output ) . I donot know what is the problem.

Maybe that cjpeg program detects that it wasn't started from the console and sits quietly?

[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);  
  }

To copy to clipboard, switch view to plain text mode 

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.