evild4ve's questions

I have a systemd timer service which runs a script every 5 minutes to check if the monitor has been powered off. If it is powered off, it locks the screen.

But I'm having some problems with the users and permissions. It seems the script must be run as sudo to query the monitor's power state, but this causes the xsecurelock to require the root password to unlock the screen. How can I fix this?

I should say: I want to keep this approach and the use of xsecurelock since this is working on my other PCs. Needing sudo to query the power state seems peculiar to this PC.

1. Systemd service

Description=Check if Monitor is switched off and run xsecurelock
After=network.target

[Service]
User=dave
Environment=XAUTHORITY=/home/dave/.Xauthority
Environment=DISPLAY=:0
Type=simple
ExecStart=/home/dave/monitor_check.sh --debug
StandardOutput=journal
StandardError=journal
Restart=no
[Install]
WantedBy=multi-user.target

2. Script

XSECURELOCK_SAVER=saver_xscreensaver
export XSECURELOCK_SAVER
echo "The value of XSECURELOCK_SAVER is: $XSECURELOCK_SAVER"

    state=$(ddcutil getvcp D6 2>&1)
        echo "$state"
    sleep 2

    if [[ "$state" == *"Display not found"* ]]; then
        echo "Monitor is off, executing command..."
        exec xsecurelock
        break
    else
    echo "Display is found, nothing to do."
    fi

This is on Ubuntu Studio 20.04 with an SPDIF / IEC958 optical connection to a multichannel AV receiver. It's in stereo not 5.1.

The soundcard is HDA Intel AD1989B Kernel version is 5.4.0-126-lowlatency

There are two overlapping sounds - a constant hissing/white noise and a constant, regular clicking-thrumming (every 0.25s). I'm not certain when they started but they haven't always been there. I'm pretty sure it was after the upgrade from 18.04 to 20.04. What applications are open doesn't affect it.

Both sounds start up when the Xfce splash screen appears - toward the end of the boot sequence. They carry on until the next reboot or shutdown. Unless:-

• I play any audio file in any program. This must have sufficient volume for it to work though. (if I play vlc in the background it has to be >5% to stop the thrumming) (it starts again immediately afterward)

• I reload ALSA (it starts again immediately afterward)

• I restart pulseaudio (it starts again immediately afterward)

• I mute the sound

The sounds aren't visible in Pavucontrol. So this might be purely in the sound hardware - perhaps picking up static from the card's idle state? Other devices going into the AV receiver don't have issues.

The sounds vary in volume, and independently from each other. The clicking-thrumming gradually worsens the longer it goes on, and restarting pulseaudio can reduce it back down. They never rise to the point of being painful or drowning out conversation.

There have been several other posts about similar problems, to do with soundcard powersave. My gut feeling is that there might be some other config file for this that has been missed off the other solutions:-

Buzzing sound when speaker idle

I don't have the file mentioned

Laptop Soundcard buzzing when not in use

I tried this and it didn't work

External speakers are buzzing when no sound is playing

I tried these and they didn't work

Strange hissing sound from speakers when idle

I tried this and it didn't work

Buzzing from external speakers, think it's related to power management

I read this but didn't do any of it except this one check

$ cat /sys/module/snd_hda_intel/parameters/power_save_controller

N

So the list below seem to be possible places where a powersave setting could be. I wonder if Ubuntu Studio and/or Xfce might have some additional possible config files?

sudo nano /usr/lib/pm-utils/power.d/intel-audio-powersave

etc/modprobe.d/audio_powersave.conf

/etc/modprobe.d/alsa-base.conf

sudo nano /etc/default/grub

/etc/pulse/default.pa

I'm not sure what I will do next. I might try some of the other possible connections from soundcard to receiver but will need more wires and I think I might have disabled them somewhere in the past. Upgrading to 22.04 and seeing if it works - this will be difficult because it's broken on my system at the moment saying not all packages are up-to-date when they are.

I'd be most grateful for any suggestions or solutions

When I plug in a PS4 dualshock controller, via USB, a Bluetooth Authentication message pops up in the top right corner with:-

Bluetooth Authentication Authorisation request for: Wireless Controller (##:##:##:##:##:##) Service: Human Interface Device Service (HID) Always Accept | Accept | Deny

1. according to the panel icon (blueman-applet), Bluetooth isn't On
2. Choosing "always accept" doesn't do anything, the message just pops up repeatedly (until they fill the whole screen)

How do I either 'Always Accept', or stop the messages popping up?

This is Xfce added onto Ubuntu Studio 20.04.

The graphics card is GeForce GTX970 and the proprietary legacy driver v390. Which is pretty stable and has been working for years.

There are two monitors side-by-side. The problem affects both desktop areas.

Sometimes when the computer boots up, the desktop area is unresponsive: if a window is minimized an image of it stays on the screen; or if a window is moved it leaves afterimages of itself. The Xfce menus and panels all work okay, and the desktop folder opens fine in Thunar. It's just the displaying of it.

Other times, it's fine.

In Xubuntu 20.04, if a window won't close first time, it brings up a dialogue with words to the effect of "This application is taking a long time to close, do you want to kill the process?"

What is it actually doing? Is it something like sending 5 close requests with a 5s interval between them and if the process is still running it then offers the user to send a kill request?

Can the number of attempts or the interval be changed somewhere as a setting? Or is there any way to add "kill" to the right mouse menu?

I have a home-media fileserver, to which I have connected a new user on Ubuntu 20.04 (via Samba). The file-server is a micro-PC doing the job of a NAS.

The new user is aged 9 and would like read permissions to a couple of folders of kids' videos, her own files, etc. I could just make her a local copy of them, but it would be nicer to find some way of limiting the access from the guest-side rather than on the server.

I'm interested in leaving the user with root permissions to the samba share but apparently-limiting it some other way in the UI

1. Is there an intentionally-hamstrung / read-only filemanager I can install that doesn't have any ability to delete or change files? Or which can use an internal allowed or disallowed lists of folder locations, without reference to the user's permissions?

2. Is it (likely to be) possible to remove the -rm and -mv commands from Thunar's capabilities? e.g. custom actions could be used to disable the 'delete' key (and it isn't in the menus) but there is still the ability to navigate around on the fileserver. In this case the "parent" directory literally is the parent's directory

3. Is there any parental controls-type utility that can restrict File Managers as well as, or instead of, Internet access?

4. As an alternative to 1. this is only for playing media, so is there any client-only "Video Jukebox" application that can't move/rename/delete?

5. Also as an alternative to 1. I could potentially set up a media server application on the fileserver, round the side of Samba - but this doesn't seem like it would be simple with the packages available to Puppy Linux

===

People often say "children find ways round these things", but this involves a bunch of assumptions about ability levels - remember my workaround is to make a local copy

thanks xx Catty

hi I'm trying to install a theme on Ubuntu Studio 20.04 with Xfce. It is a theme from gnome-look.org

The various online guides for Xubuntu say to go to Whisker Menu > Window Manager to choose a theme, and that this menu is reading /usr/share/themes

But not all the folders there appear in the Window Manager, including the new one I want to add

And there is a second UI/frontend tool in the Menu at Settings > Appearance which shows a slightly different list of themes but also not including the one I've copied to the /usr/share/themes folder. Both menus work.

I tried using Catfish to search for folders containing 'Greybird' and there is also a folder /snap/gtk-common-themes/1514/share/themes, but this doesn't have all the themes of either UI menu and presumably these themese came in with something I installed via Snap

Some online guides mention /.local/usr/share or ~/.themes/ but on my system these folders don't exist

Neither frontend has the option to add/install a theme or says where it is looking

I tried giving rw permissions on the new folders but this doesn't seem to make them appear in the UI.

Are there certain files that must be present in the theme's directory for the UI to pick it up? (if so this would have been important for the online guides to have mentioned) some of the ones my UI recognizes had a .theme file inside, but not all of them and I didn't notice something common to all.

Should I install xfce-theme-manager or is that deprecated? I worry it would just give an extra broken UI and folders.

Or since it is Xfce is there a config file where the paths to the downloaded themes can be typed in?

Thanks for your time xx Catty

I've just noticed that Thunar on my pc COPIES files when they are dragged and dropped into another folder, rather than MOVING them.

There is another answer to this question saying Thunar can MOVE files by dragging and dropping with the right mouse button. But I'd be grateful to know if it's possible to change the behaviour for dragging and dropping with the left mouse button from COPY to MOVE?

thanks, Catty