[SOLVED] How to choose which display (on dual monitor) when starting a program

[Paddy Landau]

I have two screens (dual monitor).

Generally, X11 chooses on which screen to start a program, and it's quite sensible about it.

However, there are a couple of programs that I always want to start on a specific display.



Sometimes, a program specifically has an option for this. For example, firefox has a startup option --display=DISPLAY. In this case, what do I put as DISPLAY? I tried firefox --display=0 and firefox --display=VGA, but neither works ("Error: cannot open display: 0").
What about if a program doesn't have a specific option for the display? Is there a way to specify in which screen to start the program?

[Paddy Landau]

Bump?

[northern lights]

Edit the launcher(s) for these apps. In the box titled "Command:" enter
DISPLAY=:0 ACTUAL COMMANDwhere ACTUAL COMMAND is what is already written there.

For the other monitor, make it "DISPLAY=:1"

[Paddy Landau]

Thanks for the advice.

Unfortunately, it doesn't work. I've used firefox as the test program.


From the Terminal:

"DISPLAY=:0 firefox" and "firefox --display=:0" both start firefox in the secondary monitor.
"DISPLAY=:1 firefox" and "firefox --display=:1" both return the error, "Error: cannot open display: :1".





From the menu:

"DISPLAY=:0 firefox" returns the error, "Failed to execute child process "DISPLAY=:0" (No such file or directory)".
"firefox --display=:0" opens firefox in the secondary monitor.
"DISPLAY=:1 firefox" returns the error, "Failed to execute child process "DISPLAY=:1" (No such file or directory)".
"firefox --display=:1" does nothing (presumably because of the error).



Is there, perhaps, some sort of setup I have to do first?

[northern lights]

How about "DISPLAY:=0.1" instead of "...:=1"?!

[Paddy Landau]

I must have something incorrectly set up.
I get an error for every one of the following.


DISPLAY=:0.1
DISPLAY=:0.2
DISPLAY=:1.0
DISPLAY=:1.1
DISPLAY=:1.2

However, the following (default value) does work, albeit on the secondary monitor.


DISPLAY=:0.0

Do you know where this is documented? I don't find it in man (presumably I'm looking in the wrong places).

[unutbu]

When you have two monitors, X treats them as one display with (DISPLAY=:0.0) with a big resolution. You can control the location of some apps by using a "geometry" flag. For instance:


gnome-terminal --geometry=100x20+500+500

will open a gnome-terminal which is 100 characters wide, 20 charactors long (vertically), and which has its upper left corner set at pixel coordinate (500,500).

Firefox, on the other hand, is notoriously obstinant -- FF has no geometry flag.

There is a package, devilspie, which can give you a lot of control over where all windows appear, however. I don't use devilspie, so I can't give you specific instructions, but these might point you in the right direction:

https://help.ubuntu.com/community/Devilspie
http://burtonini.com/blog/computers/devilspie
http://foosel.org/linux/devilspie
http://ubuntuforums.org/showthread.php?t=634048

[Paddy Landau]

Thanks for the information.

Devil's Pie is a fairly complex system, and I'll require a fair bit of experimentation to get it to work.

I also found a GUI interface to it from Google:
http://code.google.com/p/gdevilspie/
That's a help, too.

I've installed devilspie and gdevilspie and will slowly learn it.

[Paddy Landau]

Hmm...

I've installed devilspie and gdevilspie, and experimented.

Devil's Pie works, but only on existing windows when it starts up. It doesn't work on new windows.

For example, if I start devilspie and then open Firefox, then Firefox opens in its usual place. But, if I then kill devilspie and restart it, then it moves Firefox's window to the right place.

Do you know how I fix this problem and get devilspie to work on all windows created after devilspie has started running?

(Strange name, "Devil's Pie"!)

[unutbu]

Please post your devilspie script.
Not sure that I can help, but I'll see if I can get it to work on my machine...

[Paddy Landau]

Please post your devilspie script.
Not sure that I can help, but I'll see if I can get it to work on my machine...
Here it is. It was automatically generated by gdevilspie. As I said, it works if I kill devilspie and restart it (on the existing windows only). The indentation is mine; the original doesn't have it.

; generated_rule Thunderbird - open email
( if
( and
( is ( application_name ) "Thunderbird" )
( matches ( window_name ) ".*- Thunderbird" )
)
( begin
( geometry "890x970+1400+0" )
( println "match" )
)
)Thanks for looking at this for me.

[unutbu]

Try replacing your current script with this:


(debug)
( if
( is ( application_name ) "Thunderbird" )
( begin
( geometry "890x970+1400+0" )
)
)


If it doesn't work:
Open a terminal and type:

killall devilspie
devilspie
Open a thunderbird window to exhibit the problem.
Then post the output from devilspie.

If it does work:
Take out the (debug) line from the script and you should be good to go.

[Paddy Landau]

Interesting. When I started devilspie, it gave the following output, clearly related to those windows already open.

got eof
Window Title: 'paddy@paddy-ubuntu: ~'; Application Name: 'paddy@paddy-ubuntu: ~'; Class: 'Gnome-terminal'; Geometry: 1280x800+0+224

** (devilspie:13329): CRITICAL **: e_sexp_eval: assertion `f->tree != NULL' failed
Window Title: 'Inbox - Thunderbird'; Application Name: 'Thunderbird'; Class: 'Thunderbird-bin'; Geometry: 1280x1000+1280+0

** (devilspie:13329): CRITICAL **: e_sexp_eval: assertion `f->tree != NULL' failed
Window Title: 'Desktop'; Application Name: 'File Manager'; Class: 'Nautilus'; Geometry: 2560x1024+0+0

** (devilspie:13329): CRITICAL **: e_sexp_eval: assertion `f->tree != NULL' failed
Window Title: 'Bottom Expanded Edge Panel'; Application Name: 'Bottom Expanded Edge Panel'; Class: 'Gnome-panel'; Geometry: 1280x24+1280+1000

** (devilspie:13329): CRITICAL **: e_sexp_eval: assertion `f->tree != NULL' failedThen, when I opened a new email, it gave the following extra output.

Window Title: 'Mozilla Thunderbird'; Application Name: 'Thunderbird'; Class: 'Thunderbird-bin'; Geometry: 900x800+1280+0

** (devilspie:13329): CRITICAL **: e_sexp_eval: assertion `f->tree != NULL' failedI don't know where to look up these "CRITICAL" codes; do you? I don't find any troubleshooting or error codes anywhere in the official Devil's Pie pages.

[Paddy Landau]

Stop press...

It's working, despite those messages!

I'll now experiment to find out where I went wrong, and post the results once I've found out.

[overdrank]

Moved to Multimedia & Video :)

[Paddy Landau]

I'll now experiment to find out where I went wrong, and post the results once I've found out.
I have to thank you for pointing me in the right direction.

It seems that when Thunderbird opens a window, it opens it as one name and immediately renames it. Thus, my initial condition, which included the window name, was causing Devil's Pie to skip it.

Thanks again!

[mixmastamyk]

Been wrestling with the same problem and was able to beat Thunderbird into submission like so. Doesn't need a background process either. Put this into the launcher icon:


sh -c "thunderbird %u & sleep 3; wmctrl -r thunderbird -b remove,maximized_vert,maximized_horz; wmctrl -r thunderbird -e 0,1920,0,1200,1600"

[BicyclerBoy]

If you use separate x screens for each display then the DISPLAY variable works..

This is a config option for nvidia X server.

Most apps stay on the screen they are launched from etc..
Complete video mode independence etc..