run external application in linux using qprocess

Question

I am creating an GUI application using QT creater in Raspbian. When I click a button I want to open an external application like terminal, or browser, etc.

I have tried many attempts

attempt 1

std::system("/usr/share/raspi-ui-overrides/applications/scratch.desktop&");

it says me permission denied

attempt 2

QDesktopServices::openUrl(QUrl("/usr/share/raspi-ui-overrides/applications/scratch.desktop"));

this one is working but its not opening the application but its opening in terminal:

QDesktopServices::openUrl(QUrl("/usr/share/raspi-ui-overrides/applications/scratch.desktop"));

Are you able to execute /usr/share/raspi-ui-overrides/applications/scratch.desktop& from a terminal? — R Sahu
– R Sahu, Commented May 28, 2019 at 5:17

afenster · Accepted Answer · 2019-05-28 05:19:12Z

1

I'm assuming the question is about Raspberry Pi and Raspbian.

In Raspbian, the scratch.desktop and other *.desktop files are not executables, but just text files that describe which application to run.

Example:

pi@raspberrypi:~ $ cat /usr/share/raspi-ui-overrides/applications/scratch.desktop 
[Desktop Entry]
Encoding=UTF-8
Version=1.0
Type=Application
TryExec=scratch
Exec=scratch
Icon=scratch
Terminal=false
Name=Scratch
Comment= Programming system and content development tool
Categories=Application;Development;
MimeType=application/x-scratch-project

You need to use an actual binary to start the process. For scratch, it would be /usr/bin/scratch. For a browser, it's likely to be /usr/bin/epiphany-browser. Look at Exec= line in the *.desktop file to see the name of the executable, then use which in the terminal to see its location:

pi@raspberrypi:~ $ which epiphany-browser 
/usr/bin/epiphany-browser

answered May 28, 2019 at 5:19

afenster

3,63821 silver badges26 bronze badges

Sign up to request clarification or add additional context in comments.

7 Comments

Mohd Viquar Over a year ago

Hi I have tried using this path /usr/bin/scratch still the application is not opening

afenster Over a year ago

Does it work if you run /usr/bin/scratch in the terminal?

afenster Over a year ago

Also, it's not QDesktopServices::openUrl, it's more likely QProcess::execute as @eyllanesc suggests.

eyllanesc Over a year ago

@MohdViquar use QProcess::startDetached("/usr/bin/scratch");

Mohd Viquar Over a year ago

hi yes its working when I use /usr/bin/scratch on qprocess::execute command how to find the location of other application? thanks

|

eyllanesc · Accepted Answer · 2019-05-28 05:37:59Z

1

The .desktop files are not executable, but serve as shortcuts for the desktop system. Assuming that the scratch.desktop has the following:

scratch.desktop

[Desktop Entry]
Name=Scratch
Comment= Programming system and content development tool
Exec=scratch
Terminal=false
Type=Application
Icon=scratch
Categories=Development;
MimeType=application/x-scratch-project

Then the executable is /usr/bin/scratch, And you can run it with Qt:

QProcess::startDetached("/usr/bin/scratch");

Or:

QProcess::execute("/usr/bin/scratch");

edited May 28, 2019 at 5:37

answered May 28, 2019 at 5:25

eyllanesc

246k19 gold badges205 silver badges282 bronze badges

Collectives™ on Stack Overflow

run external application in linux using qprocess

2 Answers 2

7 Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

7 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related