Segmentation fault (core dumped) on my application

[Hamed.Masafi]

@Renn No, they are not same. The a with qApp and QApplication::instance() is equal.
Can you please paste full source (main.cpp, ui_class.cpp and ui_class.h) ?

[jsulm]

@Renn Well, I think if you don't call ui->setupUi(this) then ui->browse will probably be null and you just dereference a null pointer which leads to the segmentation fault.
ui->setupUi(this) initializes all the stuff in ui.

if(getuid() > 0){
// Here you do not call ui->setupUi(this);!
pkexec.start("pkexec " + locate);
pkexec.waitForFinished();
}
else{
ui->setupUi(this);
}

[Renn]

@jsulm What should I do now? If I put ui-> setupUi (this); before and after, there are still some more than one, the other one did not go through pkexec root, while the other was entering through pkexec root.

[Renn]

@Hamed.Masafi Oh not the same, this is code that really complete the form ui is just testing me so that the application can go through pkexec root. under the code themselves:
untitled.h
#ifndef UNTITLED_H
#define UNTITLED_H
#include <QMainWindow>

namespace Ui {
class untitled;
}

class untitled : public QMainWindow
{
Q_OBJECT

public:
explicit untitled(QWidget *parent = 0);
~untitled();

private slots:

private:
Ui::untitled *ui;
};
#endif // UNTITLED_H

untitled.cpp
#include "untitled.h"
#include "ui_untitled.h"
#include <QProcess>
#include <QDebug>
#include <QFileDialog>
extern QString locate;
untitled::untitled(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::untitled)
{
//ui->setupUi(this);
qDebug() << getuid();
QProcess pkexec;
if(getuid() > 0){
//ui->setupUi(this);
pkexec.start("pkexec " + locate);
pkexec.waitForFinished();
ui->setupUi(this);
}
// else{
// ui->setupUi(this);
// }
//Change button to Icon Image

QPixmap pix("/home/rnd/untitled/image/image.ico");
QIcon icon(pix);
//ui->browse->setIcon(icon);
//ui->browse->setIconSize(pix.size());

}

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

main.cpp
#include "untitled.h"
#include <QApplication>
QString locate;
int main(int argc, char *argv[])
{
QApplication a(argc, argv);
locate = a.arguments().at(0);
untitled w;
w.show();

return a.exec();

}

[Hamed.Masafi]

#include "untitled.h"
#include "ui_untitled.h"
#include <QProcess>
#include <QDebug>
#include <QFileDialog>
extern QString locate;

untitled::untitled(QWidget *parent) : QMainWindow(parent), ui(new Ui::untitled)
{
	qDebug() << getuid();
	QProcess pkexec;
	if(getuid() > 0){
		//ui->setupUi(this);
		pkexec.start("pkexec " + locate);
		pkexec.waitForFinished();
	}
	
	ui->setupUi(this);

	//Change button to Icon Image
	QPixmap pix("/home/rnd/untitled/image/image.ico");
	QIcon icon(pix);
	//ui->browse->setIcon(icon);
	//ui->browse->setIconSize(pix.size());
}

[Renn]

@Hamed.Masafi That's the same mas, will appear 2 form as I mentioned earlier..

[jsulm]

@Renn You should explain better what you actually want to do. Why do you call ui->setupUi(this) only if getuid()>0?

if(getuid() > 0){
// Do you want to have an UI in this case?
pkexec.start("pkexec " + locate);
pkexec.waitForFinished();
}
else{
ui->setupUi(this);
}

[Hamed.Masafi]

Oh, you'r right, but what is getuid() ??

[Renn]

@jsulm Actually I outsmart gui so that I can enter the root through the framework polkit using pkexec in QProcess. When I write code
ui->setupUi (this);
pkexec.start("pkexec" + locate);
pkexec.waitForFinished();
form it appears 2, I outsmart menggunakai if else, in part if I enter the command QProcess and else that I enter ui->setupUi(this);
When I was running in qt no anything, but when I run through the terminal, at that time I realized that my application that I made it crashes with a notice "Segmentation fault (core dumped)"

[jsulm]

@Hamed.Masafi Get user ID (man getuid)

[Renn]

@jsulm Now I have to do?