Thanks! Marking solved.

How can I fix this problem?

Writing a newline separately works, as suggested by micland. Thanks guys!

We can do something. You need to use event filters along with process communication. Can you paste the which you have tried ? That will help us quickly get you the solution.

Do you have any logging going on that would allow you to check whether your nodejs server does something ?

One thing to add to @kshegunov, terminating these applications ungracefully may have side effects on the stability of your system.

@marlenet15

@Paul-Colby said:

Of course you should always be careful with sudoers, but even more so when using wildcards.

That's good advice and only to throw my 2 cents in:
Allowing users to change system-wide settings somehow defeats the whole point of having users in the first place. What happens if one user changes the timezone, but another is not happy with that and changes it back? These are system changes we're talking about, so that's one good reason for actually having a super user that manages them ...

Hi,
Thanks for your response. The whole body of code is proprietary so I'm not sure I can share it in a public forum.
However I can make a note that it used to work fine a month ago and after that no changes occurred to this code and no qt libraries were replaced, so the issue is like to be caused by hardware malfunction.

Thanks again ))

Glad you found out and thanks for sharing !

Since you have it working now, please mark the thread as solved using the "Topic Tool" button so that other forum users may know a solution has been found :)

Basically, it's not a part of Qt that you access directly. It's part of the platform plugins that abstracts away the differences between the various supported OSs.

The best I can recommend is to contact the KDE folks about how the startup notification is handled by them.

@SGaist Thanks, it helped!

I realized that the command was wrong and wasn't recognizing my partitions.

@the_

will work

Such a strong word ... it depends on the advisory locking mechanism used and most linux-es will support more than one. As duly noted in the documentation it's only guaranteed to work if the same scheme is used across all processes:

Serialization is only guaranteed if all processes that access the shared resource use QLockFile, with the same file path.

Thanks again,
Does seem implementing the startDetached() is the better option ( if i understand correctly) as when the app closes , closing down the started sup processes could be problematic.

On a side note:
Needing to keep the instance around is also an interesting complexity, if logic serves,

The app starts a process (perhaps stored in a QList Or QHash) Maintain the state so when the sup-process terminates i can ether re-use the process or remove the process and create another instance .
*with the understanding that if the main app closes all sup-process's will close.

Is the logic sound?

Thank you!

QString file = filemodel->data(index, Qt::DisplayRole).toString(); QDesktopServices::openUrl(QUrl::fromLocalFile(file));

Works perfekt! :D

thank you for ALL !!!
I present final solution
header

#ifndef MAPP_H #define MAPP_H #include<QCoreApplication> #include<QProcess> #include<QFile> class mApp : public QCoreApplication { Q_OBJECT QProcess* fproc; const QString progName{"/usr/bin/firefox"}; const QStringList wwwSite{{"localhost"},{"-P marek"},{"-no-remote"}}; const QStringList killffox{{"firefox"}}; public: mApp(int argc, char *argv[]); ~mApp(); signals: public slots: void ffoxClose(int a); }; #endif // MAPP_H

souce

#include "mapp.h" #include<QFileInfo> mApp::mApp(int argc, char *argv[]):QCoreApplication(argc, argv) { fproc=new QProcess(this); QFileInfo lock("/home/tygrysy/.mozilla/firefox/marek/lock"); //file exist when firefox is run if (lock.isSymLink()){ fproc->start("killall",killffox); fproc->waitForFinished(); } fproc->start(progName,wwwSite); connect(fproc,SIGNAL(finished(int)),this, SLOT(ffoxClose(int))); } mApp::~mApp() { fproc->close(); fproc->destroyed(); } void mApp::ffoxClose(int a) //gdy aplikacja się skończy to odpalam ponownie { QFileInfo lock("/home/tygrysy/.mozilla/firefox/marek/lock"); // file exist when firefox run :P if (!lock.isSymLink()){ fproc->start(progName,wwwSite); } }

Good !

Since you have it working now please mark the thread as solved using the "Topic Tool" button so that other forum users may know a solution has been found :)