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

[jacek]

but it is public QDialog whereas you have gone for public QObject.Do I have to stick to Public Qobject only.

What is the difference between QObject and QDialog?

steg t (s2);

You create "t" on the stack and it gets destroyed immediately (together with QProcess), because it goes out of scope.
Instead of creating a new dialog, move the code that creates the process to steg::stego() slot.

[deekayt]

It does not work. I have now made steg.h as

#ifndef STEG_H
#define STEG_H
#include "ui_stegform1.h"
#include <QProcess>
#include <QMessageBox>
class steg  : public QDialog 
 {
     Q_OBJECT
 public:
     steg(QWidget *parent = 0); 
      QProcess *_proc;   
    // steg(QStringList s2)
      //{
	//   _proc = new QProcess( this );
               // _proc->setReadChannelMode( QProcess::MergedChannels );
	// connect( _proc, SIGNAL( readyReadStandardOutput() ), this, SLOT( read()));
	// connect( _proc, SIGNAL( finished(int, QProcess::ExitStatus) ), QCoreApplication::instance(), SLOT( quit() ) );
	// _proc->start(("cjpeg"),s2);
     // }
 
private slots:       
        void stego();
        void read()
      	 {
              QMessageBox::information( 0, "stego", _proc->readAllStandardOutput());
     		 }
private:
     Ui::steg ui;     
 };
#endif

#ifndef STEG_H
#define STEG_H
#include "ui_stegform1.h"
#include <QProcess>
#include <QMessageBox>
class steg  : public QDialog 
 {
     Q_OBJECT
 public:
     steg(QWidget *parent = 0); 
      QProcess *_proc;   
    // steg(QStringList s2)
      //{
	//   _proc = new QProcess( this );
               // _proc->setReadChannelMode( QProcess::MergedChannels );
	// connect( _proc, SIGNAL( readyReadStandardOutput() ), this, SLOT( read()));
	// connect( _proc, SIGNAL( finished(int, QProcess::ExitStatus) ), QCoreApplication::instance(), SLOT( quit() ) );
	// _proc->start(("cjpeg"),s2);
     // }

private slots:       
        void stego();
        void read()
      	 {
              QMessageBox::information( 0, "stego", _proc->readAllStandardOutput());
     		 }
private:
     Ui::steg ui;     
 };
#endif

To copy to clipboard, switch view to plain text mode 

and steg.cpp as

void steg::stego()  /*** THIS MODULE  HIDES  CODED.TXT ***/
{
	  if(QFile::exists("coded.txt")) 
			{  
			QStringList s2;
			s2 << "-steg" << "coded.txt" << "-q" << ui.compressionspinBox->text() << "cleanimage.ppm" << ui.jpeglineEdit ->text() ;
		 	//QProcess *_proc;
			_proc = new QProcess( this );
			_proc->setReadChannelMode( QProcess::MergedChannels );
 
	 		connect( _proc, SIGNAL( readyReadStandardOutput() ), this, SLOT( read()));
			// connect( _proc, SIGNAL( finished(int, QProcess::ExitStatus) ), QCoreApplication::instance(), SLOT( quit() ) );
			 _proc->start(("cjpeg"),s2);
			read();
	}

void steg::stego()  /*** THIS MODULE  HIDES  CODED.TXT ***/
{
	  if(QFile::exists("coded.txt")) 
			{  
			QStringList s2;
			s2 << "-steg" << "coded.txt" << "-q" << ui.compressionspinBox->text() << "cleanimage.ppm" << ui.jpeglineEdit ->text() ;
		 	//QProcess *_proc;
			_proc = new QProcess( this );
			_proc->setReadChannelMode( QProcess::MergedChannels );

	 		connect( _proc, SIGNAL( readyReadStandardOutput() ), this, SLOT( read()));
			// connect( _proc, SIGNAL( finished(int, QProcess::ExitStatus) ), QCoreApplication::instance(), SLOT( quit() ) );
			 _proc->start(("cjpeg"),s2);
			read();
	}

To copy to clipboard, switch view to plain text mode 

I have to have _proc declared in steg.h since I use it in read() also.
I donot know where is the problem

[jacek]

What happens if you add:

connect( _proc, SIGNAL( started() ), QApplication::instance(), SLOT( aboutQt() ) );

connect( _proc, SIGNAL( started() ), QApplication::instance(), SLOT( aboutQt() ) );

To copy to clipboard, switch view to plain text mode 

?

P.S. There is no sense in calling read() in stego(), QProcess will send a signal when there is something to read.

[deekayt]

The code now looks like

QStringList s2;
			s2 << "-steg" << "coded.txt" << "-q" << ui.compressionspinBox->text() << "cleanimage.ppm" << ui.jpeglineEdit ->text() ;
		 	//QProcess *_proc;
			_proc = new QProcess( this );
			_proc->setReadChannelMode( QProcess::MergedChannels );
 
	 		connect( _proc, SIGNAL( readyReadStandardOutput() ), this, SLOT( read()));
			connect( _proc, SIGNAL( started() ), QApplication::instance(), SLOT( aboutQt() ) ); 
 
			// connect( _proc, SIGNAL( finished(int, QProcess::ExitStatus) ), QCoreApplication::instance(), SLOT( quit() ) );
			 _proc->start(("cjpeg"),s2);
 
			//read();

QStringList s2;
			s2 << "-steg" << "coded.txt" << "-q" << ui.compressionspinBox->text() << "cleanimage.ppm" << ui.jpeglineEdit ->text() ;
		 	//QProcess *_proc;
			_proc = new QProcess( this );
			_proc->setReadChannelMode( QProcess::MergedChannels );

	 		connect( _proc, SIGNAL( readyReadStandardOutput() ), this, SLOT( read()));
			connect( _proc, SIGNAL( started() ), QApplication::instance(), SLOT( aboutQt() ) ); 

			// connect( _proc, SIGNAL( finished(int, QProcess::ExitStatus) ), QCoreApplication::instance(), SLOT( quit() ) );
			 _proc->start(("cjpeg"),s2);

			//read();

To copy to clipboard, switch view to plain text mode 

Now I get the About QT inboth the case that is when there would be error message and when there is no error message.
I know that the program has worked fine ( data has been succesfully hidden ) after seeing the concerned file and classicaly speaking noerroror otherwise any message is not given on thecommand console hence nothing should come in the message pop also.But The About QT screen does come everytime.
The screen snapshot is attached as zip.
What do you say??

[jacek]

Now I get the About QT inboth the case that is when there would be error message and when there is no error message.

This means that the program was started successfully. Maybe you kill it immediately? Does my test program work on your system?

[deekayt]

Dear JACEK

I have tried to run the main.cpp but could not.
How did you run it .
I understand that I should have some form ( Q Dialog) and then on click of button the object should be made
thus runing the cjpeg.exe,since you had incorporated in the constructor only.
The error which I got while doing MAKE is in the erro_text_file.txt attached alongwith.
The code is at the test.zip file.

[jacek]

I have tried to run the main.cpp but could not.
How did you run it .

My program, without any modifications, should compile without any problems. In fact it's a self contained example which verifies that cjpeg.exe output can be captured --- it doesn't need any modifications to run.

The error which I got while doing MAKE is in the erro_text_file.txt attached

If you look closely you will see, that all error messages are referring to your code. If run qmake again, it should compile.

[deekayt]

I tried your code without modification
I should be getting the error since you had supplied invalid arguments "aaa" and "bbb"

_

proc->start( "cjpeg", QStringList() << "aaa" << "bbb" );

proc->start( "cjpeg", QStringList() << "aaa" << "bbb" );

To copy to clipboard, switch view to plain text mode 

and one should be getting the message box with the error captured.
The test1 does get compiled but when i run it nothing happens.It does get started which I see in the process runing in the Task Manager window of the operating system.
but that's all.No message at all.
I am attaching the whole folder which I compiled.
You will notice that I have edited makefile since I donot want any references to debug . Because when I make with the unedited makefile I get the error as captured in error_text1_file.txt.I did not want to repair the QT make thing hence this shortcut of first deleting all refernces to debug in makefile and then making the makefile.
Is it because of this shortcut that I am not getting the right thing from your main.cpp or is it something else.

Secondly you mentioned about the

"If you look closely you will see, that all error messages are referring to your code."

how to get this vtable error corrected

[jacek]

The test1 does get compiled but when i run it nothing happens.

How do you start it?

You will notice that I have edited makefile since I donot want any references to debug .

There is no need to edit automatically generated files. You have three possibilities:

1. compile Qt libraries in debug mode,
2. use "make -f Makefile.Release",
3. add:

   CONFIG -= debug_and_release
   CONFIG += release

   to the .pro file.

Secondly you mentioned about the

And I've also mentioned the solution.

[deekayt]

How am I suppose to start the test1.exe.
It is there in the release folder
I just double click hoping that message box with error will come but nothing happens.
I tried runing test1.exe from comd prompt but nothing happens.
I am still stuck.

[jacek]

I just double click hoping that message box with error will come but nothing happens.

If you start the program by double-clicking on it, the current directiry will be set to your desktop (AFAIR), but the program expects that cjpeg.exe will be in the current directory.

I tried runing test1.exe from comd prompt but nothing happens.

How? Is cjpeg.exe in the current directory?

[deekayt]

Once the test1.exe is made in the release directory of test1 folder I copy cjpeg.exe there with all other files which are required to be used . I have been doing the same for all other programs.After that either one double clicks the test1.exe after navigating to release folder or one can copy a shortcut to the desktop ( both work).I am sure that is not the problem.