Questions[xscreensaver](ubuntu)

I don't understand Linux and sys-admin stuff, but I have installed recently xscreensaver Ubuntu 18.04.4 LTS as described here and I have followed all the steps. If I lock the screen with Cntrl+Alt+L then the xscreensaver starts. But If I wait for the screen to time out, it just goes blank black like the gnome-screensaver does, despite that I have gnome-screensaver installed. Curiously, when I type locate screensaver.desktop I get:

/etc/xdg/autostart/gnome-screensaver.desktop
/home/nestor/.config/autostart/xscreensaver.desktop

I was afraid to delete the gnome-screensaver.desktop file, so I out commented everything in it. Still, same problem persists.

If after a restart I type xscreensaver -nosplash I get:

xscreensaver: 18:39:29: already running on display :0 (window 0x1a000de) 

I guess, this is good and excludes the possibility that screensaver just doesn't get automatically started on start-up.

Then I followed the instructions here and I did:

sudo apt-get remove --auto-remove gnome-screensaver
sudo apt-get purge --auto-remove gnome-screensaver
systemctl --user enable xscreensaver.service
systemctl --user start xscreensaver.service

After the last command I got the message:

Failed to start xscreensaver.service: Unit xscreensaver.service is not loaded properly: Exec format error.
See user logs and 'systemctl --user status xscreensaver.service' for details.

The referred log says:

● xscreensaver.service - XScreenSaver
   Loaded: error (Reason: Exec format error)
   Active: inactive (dead)

апр 03 18:07:22 nestor-Eve-V systemd[1492]: /usr/lib/systemd/user/xscreensaver.service:5: Executable path is not absolute: xscreensaver
апр 03 18:07:22 nestor-Eve-V systemd[1492]: xscreensaver.service: Cannot add dependency job, ignoring: Unit xscreensaver.service is not loaded properly: Exec format error.

This suggests the problem is "Executable path is not absolute", so I opened the file /usr/lib/systemd/user/xscreensaver.service and it contains:

[Unit]
Description=XScreenSaver
[Service]
ExecStart=xscreensaver
[Install]
WantedBy=default.target

Do I have to type there an absolute path? Any ideas how can I enable screensaver to work properly? thanks

How do I add a screensaver to the startup application? I have used this command:

xscreensaver -no-splash

What am I doing wrong or not doing? I am using the latest Ubuntu version.

I have installed Ubuntu 18.04 but found gnome too heavy for my old hardware.

So I installed Xubuntu-desktop:

sudo apt-get install xubuntu-desktop synaptic
sudo apt-get remove gdm3
sudo dpkg-reconfigure lightdm
sudo apt-get remove nautilus nautilus-* gnome-power-manager gnome-screensaver gnome-termina* gnome-pane* gnome-applet* gnome-bluetooth gnome-desktop* gnome-sessio* gnome-user* gnome-shell-common zeitgeist-core libzeitgeist* gnome-control-center gnome-screenshot && sudo apt-get autoremove

It worked beautifully, but now, sometimes xscreensaver locks my screen, sometimes lightlocker does.

I have them both installed, apparently:

$ sudo dpkg -l | grep locker
rc  gnome-screensaver                                           3.6.1-8ubuntu3                                     amd64        GNOME screen saver and locker
ii  light-locker                                                1.8.0-1ubuntu1                                     amd64        simple screen locker for lightDM display manager
ii  light-locker-settings                                       1.5.0-0ubuntu2                                     all          simple configuration tool for light-locker
$ sudo dpkg -l | grep xscreen
ii  xscreensaver                                                5.36-1ubuntu1                                      amd64        Screensaver daemon and frontend for X11
ii  xscreensaver-data                                           5.36-1ubuntu1                                      amd64        Screen saver modules for screensaver frontends
$ 

This is my production workstation and I'm afraid of messing it.

Having them working at the same time presents no huge problem for me, but it looks inconsistent.

I have a "Lightlocker settings" icon on my "Settings" app, but it doesn't work. So I can only configure sleep timeouts for xscreensaver. Would it be safe to remove xscreensaver (which is uglier)? And is there a way to make "Lightlicker settings" actually work and allow me to configure its timeouts? Or should I keep xscreensaver and remove lightlocker?

Thanks!

I have installed Lubuntu 12.04 and was wondering if there was a way to keep it from locking the screen when the screensaver starts?
The "lock screen after X minutes" box is unchecked, so that is not causing the problem. Does anyone know the solution for this problem? I'm not worried about security, so i don't need it locked.

I've just installed xscreensaver instead of gnome-screensaver in Ubuntu 12.04 in gnome-session-fallback (Gnome Classic) mode. It works fine, but I have a problem: I put "xscreensaver -no-splash" command to the startup applications list.

But it doesn't start automatically, I have to run this command manually. I think that the problem is that it tries to start before I log in. So how can I start it automatically after login?

Update Jan 2021

I moved to a different DE a long time ago, so this issue no longer affects me. New answers are still coming, however I cannot mark any of them as accepted as I can't test them any more.