Xfce Forum

casaschi

Member

Registered: 2013-05-11

Posts: 6

unlocking xfce4-screensaver from ssh console

Hello,

I have a new xfce4 install on ubuntu 22.04 that I access from vnc.
If xfce4-screensaver locks the screen, vnc is frozen and I can't unlock from the main display.

How can I unlock xfce4-screensaver from an ssh console?

I tried "xfce4-screensaver-command --deactivate" but I normally get an error message saying that xfce4 screensaver is not active.
Setting just the DISPLAY variable does not help.

"xfce4-screensaver-command --deactivate" works, but only from a screen session that I started from the main display and then detached.

How do I get xfce4-screensaver-command talk to xfce4-screensaver on the vnc screen?

Thanks!

casaschi

Member

Registered: 2013-05-11

Posts: 6

Re: unlocking xfce4-screensaver from ssh console

This is the exact error message I get when trying "xfce4-screensaver-command --deactivate" from the ssh terminal:

"Screensaver is not running! Start xfce4-screensaver first"

ToZ

Administrator

From: Canada

Registered: 2011-06-02

Posts: 11,485

Re: unlocking xfce4-screensaver from ssh console

I have a new xfce4 install on ubuntu 22.04 that I access from vnc.
If xfce4-screensaver locks the screen, vnc is frozen and I can't unlock from the main display.

Testing this on Arch linux using x11vnc as the server (started with "x11nvc -ncache 10 -display :0") and using xtightvnc as the viewer from a second computer, everything works fine - I can lock and lock the screen via xfce4-screensaver.

I tried "xfce4-screensaver-command --deactivate" but I normally get an error message saying that xfce4 screensaver is not active.

Doesn't ubuntu use light-locker instead of xfce4-screensaver? What does the following return:

ps -ef | grep -E 'saver|lock'

---

Please remember to mark your thread [SOLVED] to make it easier for others to find
--- How To Ask For Help | FAQ | Developer Wiki  |  Community | Contribute ---

casaschi

Member

Registered: 2013-05-11

Posts: 6

Re: unlocking xfce4-screensaver from ssh console

Thanks for responding, here is the output of the command (few irrelevant lines removed):

$ ps -ef | grep -E 'saver|lock'
ubuntu      1145       1  0 May21 ?        00:00:00 /usr/bin/xfce4-screensaver
ubuntu      1265    1193  0 May21 ?        00:00:00 /usr/lib/aarch64-linux-gnu/xfce4/panel/wrapper-2.0 /usr/lib/aarch64-linux-gnu/xfce4/panel/plugins/libactions.so 14 37748750 actions Action Buttons Log out, lock or other system actions
ubuntu      8183    8175  0 12:22 pts/0    00:00:00 grep --color=auto -E saver|lock

If this helps, this was not a direct full xubuntu installation, it started with a minimal ubuntu 22.04 cloud installation, then I added the xfce4 and xfce4-goodies.

The tricky part is that, after locking the desktop, if I simply ssh into the machine and try "xfce4-screensaver-command --deactivate", then I get the error message "Screensaver is not running! Start xfce4-screensaver first".

If instead I use the same command from a screen terminal that I had started from the xfce4 desktop and then I had detached... then "xfce4-screensaver-command --deactivate" works!

It seems to me that from a plain ssh connection, xfce4-screensaver-command does not know where to look for the screensaver process. I tried comparing the environment variables of the plain ssh and the screen session, startion from the DISPLAY=:1.0 setting, but I could not make it work.

Any suggestion welcome...

Thanks,

casaschi

Member

Registered: 2013-05-11

Posts: 6

Re: unlocking xfce4-screensaver from ssh console

I did a bit more of systematic test and the environment variable that needs to be properly set is DBUS_SESSION_BUS_ADDRESS

Unfortunately, every time the machine is rebooting the vnc session has a different value for DBUS_SESSION_BUS_ADDRESS

The question now is, how do I add a command at the xfce startup, that stores the vaue of DBUS_SESSION_BUS_ADDRESS somewhere accessible to the ssh terminal?

casaschi

Member

Registered: 2013-05-11

Posts: 6

Re: unlocking xfce4-screensaver from ssh console

Got something working... at startup the xfce4 session for vnc stores the value of DBUS_SESSION_BUS_ADDRESS somewhere so that the ssh user can set the variable accordingly, thus being able to unlock the xfce4 screensaver.