PDF open problem

mrjj

@f.lerdino
What Qt is it ?
Sounds like QDesktopServices broke with update then.
( not QDesktopServices faults but something changed in the system)

JonB

@mrjj
The final error reads:

xdg-open: no method available for opening '/home/labotdd/doc3.pdf'

I don't see how QDesktopServices per se can be blamed for that?

@f-lerdino
There are mentions of "root" in the trace. Just to check: you have no root-ness going on when you run the Qt app vs when you do it outside of Qt?

I also tried to use xdg-open mypdf.pdf and the pdf file has been opened

Please try with xdg-open /home/labotdd/doc3.pdf

Also, FWIW, can you try from your Qt app with something other than a .pdf, if your code allows it?

f.lerdino

for mrjj : I have 5.11.1 and ubuntu 16.04 -kernel 4.13.0.-45.
for JonB: if I try ro run this 'xdg-open /home/labotdd/doc3.pdf the pdf' the file is opened whitout any problem.

f.lerdino

@JonB said in PDF open problem:

Also, FWIW, can you try from your Qt app with something other than a .pdf, if your code allows it?

I have tried with a txt file and with it works....

JonB

@f.lerdino
Root-ness? Do you have anything root-y going on? By any chance, is your Qt app being run as/by root?

Is your Qt app a GUI one or command-line only? Are you running Unity or not/other?

mrjj

Hi
Also could you list what
xdg-mime query default application/pdf
returns ?

f.lerdino

@mrjj said in PDF open problem:

xdg-mime query default application/pdf

labotdd@D7050:/opt/Qt/Tools/QtCreator/bin$ xdg-mime query default application/pdf
evince.desktop

mrjj

Ok. so that is not changed.
if u type evince in a shell ( normal user) it starts as normally ?

JonB

@f.lerdino
I really think this could be a root issue, which you have not answered. If I deliberately go

sudo xdg-open .....pdf

I get messages like I see in yours:

No protocol specified
Unable to init server: Could not connect: Connection refused
Cannot parse arguments: Cannot open display: 
No protocol specified
Unable to init server: Could not connect: Connection refused
Cannot parse arguments: Cannot open display: 
Warning: program returned non-zero exit code #1

JonB

@f.lerdino
I think this is not a Qt issue per se, but an Ubuntu 16.04 one. Try Googling for something like ubuntu 16.04 xdg-open. I think https://askubuntu.com/questions/779717/xdg-open-stopped-working-since-16-04-upgrade might be where you'll find what you need to do... ?

f.lerdino

@mrjj
I have an old version of ubuntu and everything work. Something is changed after the ubuntu update. Of course I run my QT Program as root.

mrjj

@f.lerdino
The link @JonB gives , suggest that
gvfs-info being deprecated.
so that might be your actual issue.
(some posts down)

f.lerdino

@JonB
I use root to run my Qt program

mrjj

@f.lerdino
but does it work then if u dont run as root ?

JonB

@f.lerdino

I use root to run my Qt program

Scary. Which is why I asked earlier.

Given that the error messages you show are complaining as not being able to do stuff as root, I presume when you tested running the xdg-opens and said they worked you did so as root too?

f.lerdino

@JonB said in PDF open problem:

Given that the error messages you show are complaining as not being able to do stuff as root, I presume when you tested running the xdg-opens and said they worked you did so as root too?

Yes I have tried as root...

f.lerdino

Can I run as external program the pdf viewer + mypdffile in QT/Ubuntu?

Thanks

mrjj

@f.lerdino
Well you could run it via QProcess.

ndreisg

I have the same problem and it seems like the problem is caused by this firefox bug: https://bugzilla.mozilla.org/show_bug.cgi?format=default&id=1323302
(and the resulting change: https://hg.mozilla.org/mozilla-central/rev/90a06cdcb48f)

It seems like xdg-open uses firefox in background to display the PDF files.

Unfortunately it seems like the firefox team has not provided a possibility to bypass this behavior.
(Chrome Browser for example provides "--no-sandbox" option to start it as root in a non-root user session)