Xubuntu 14.04: Any way to *permanently* set default session?

General discussion relating to the O2 Joggler, from the default O2 setup, to alternative operating systems and applications.
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MikeHG
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Xubuntu 14.04: Any way to *permanently* set default session?

Post by MikeHG »

Hello,

I'm using the Xubuntu 14.04 image to run XBMC (thanks to everyone involved - it's working really well).

One bugbear is I'd like the login screen to have a particular session selected regardless of what the last thing I logged into was.

This doesn't seem easy. I've tried editing .dmrc, and the shadow copy of it in /var/cache/lightdm. I've tried changing them to root:root, and revoking write permissions. I've tried using scripts to edit them after logging out. I've tried uninstalling accountsservice. I've tried other DMs (KDM works, but has the same 'remember last used session' behaviour). I've even tried commenting out the lines that update .dmrc in LightDM's source and recompiling it - works in a VM, but won't let me actually log in on the Joggler (loading screen freezes before it gets to the greeter).

Is there a sane way to do this, or is this time to give up?

Thanks.
Juggler
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Re: Xubuntu 14.04: Any way to *permanently* set default sess

Post by Juggler »

Seems to be a bit of a PITA !

I just use one account - would that work for you ? I seem to recall that you can auto login as one account (on boot?), would that take priority over last being logged in under a different account ? All you'd need to do then is to switch accounts when logged in. Not tried this so just ideas...

Some of the other ubuntu / linux forums may have some info, as I don't think this is particular to the Joggler, or am I misunderstanding what you are asking ? But if you find the answer elsewhere, please post back here.
MikeHG
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Re: Xubuntu 14.04: Any way to *permanently* set default sess

Post by MikeHG »

Thanks for the response.

I only have one (non-ssh) account, which has no password, but I don't want to set it to autologin, because XBMC (which I use much more than anything else) does everything it can to disable power management. My Jogglers are used as a radio (often for falling asleep), and as a kitchen 'TV', so power management is essential - I want to be able to set them playing something, and have them stop and kill the screen, no matter what, X hours later.

I've achieved that by forcing them to log out automatically, since power management works at the LightDM greeter (the file in /usr/share/xsessions points to a script, which says something like 'at now +2 hours -f logout.sh; /usr/bin/xbmc-standalone', while logout.sh says something like 'killall -2 xbmc.bin').

So that's almost perfect, but the final touch would be making it *always* default to the timeout XBMC login, no matter what I picked last. It's not a huge issue, and I'm unlikely to dig any deeper (I tried compiling KDM... not going to happen :) ), but figured I'd ask if anyone had any ideas first.

Two of those annoying situations where the complex behaviour 99% of people want overrides the simple behaviour I want, and it seems to be impossible to disable without tinkering with the source.
Juggler
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Re: Xubuntu 14.04: Any way to *permanently* set default sess

Post by Juggler »

I think the most power-hungry part of a Joggler is the screen. Maybe, if your using the radio and/or the TV, after a certain amount of time you could reduce the brightness right down. Also, because your using X, you can effectively turn the screen off. I think, to do this use the xset command or something like that. There are a few threads here on that. I was quite interested in this, as was another member who started a thread and was looking at code in the end to see how X turned the screen off. But our requirement was to turn the screen off on a Joggler ubuntu without an X server.

The difference between being on full brightness and lowest is around 4 watts. Turning the screen off fully, would make an even greater saving.

Best to search for the thread here, also this may be of help:

https://systembash.com/how-to-turn-off- ... in-ubuntu/
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BuZz
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Re: Xubuntu 14.04: Any way to *permanently* set default sess

Post by BuZz »

Kodi (and XBMC before) has the ability to shut the screen off after no activity for a set period. http://kodi.wiki/view/Settings/System#Power_saving it also has a shutdown timer.
MikeHG
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Re: Xubuntu 14.04: Any way to *permanently* set default sess

Post by MikeHG »

The difficulty is I want to be able to play something like a 24 hour news channel stream, and have it switch the audio and screen off automatically after ~2 hours (without having to turn on 'Sleep mode' or something each time).

I didn't think I could make that work with the settings I could find, but I'll have more of a poke around.

Cheers for the input.
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BuZz
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Re: Xubuntu 14.04: Any way to *permanently* set default sess

Post by BuZz »

Try an addon ? a quick search brought up http://forum.kodi.tv/showthread.php?tid=154282 for example - there might be other options.
Juggler
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Re: Xubuntu 14.04: Any way to *permanently* set default sess

Post by Juggler »

On my joggler now with BuZz's xubuntu,...

Command to turn screen off fully is :

xset dpms force standby

When you press any key / move mouse, screen comes back. Could you hook this command into the x screen saver, if this still works with kodi running ? Command doesn't affect audio, so you'd need to mute the speaker, if that was required, or maybe have speaker mute on a separate schedule.
MikeHG
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Re: Xubuntu 14.04: Any way to *permanently* set default sess

Post by MikeHG »

There's a simple sleep timer plugin here, seems to work so far:

http://forum.kodi.tv/showthread.php?tid=167997

Combined with the Kodi setting to turn the screen off, I'm happy. Thanks for the suggestions
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hawsey
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Re: Xubuntu 14.04: Any way to *permanently* set default sess

Post by hawsey »

Messing around with Kodi streaming off a Plex server on my Revo 3610 and my music was stuttering badly , I blamed the Revo at first but then realised I had made a new stick up and forgot to set the thermal PSV to 80 , so I set it to 80 and problem solved :-)

BuZz , why don't you pre set your builds to 80? I have a feeling some people will try builds , find them unreliable due to throttling and give up ;
it's just a thought and apologies if I'm out of order here but I don't know of anyone saying any harm has ever come to a Thermal PSV =80 Joggler ,
Happy Joggling
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BuZz
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Re: Xubuntu 14.04: Any way to *permanently* set default sess

Post by BuZz »

hawsey wrote: BuZz , why don't you pre set your builds to 80? I have a feeling some people will try builds , find them unreliable due to throttling and give up ;
it's just a thought and apologies if I'm out of order here but I don't know of anyone saying any harm has ever come to a Thermal PSV =80 Joggler ,
I prefer to leave it to the user to make choices that could affect the life of the hardware (whether or not I think it's safe). if someone tries the image, but doesn't read the instructions, that's their problem :) I could perhaps add a more prominent note on the download page.
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hawsey
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Re: Xubuntu 14.04: Any way to *permanently* set default sess

Post by hawsey »

Suppose that's the safest way BuZz , we can always help new people get there with regards to setting the throttling higher .
Happy Joggling
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