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When I use Ubuntu 12.04, after I click the "Lock" button from status bar in desktop, it will show the locked screen. I use another computer to ssh to this locked computer. And use command 

export DISPLAY=:0    
gnome-screensaver-command -d

to unlock the screen. It works well.

But now, I upgrade Ubuntu from 12.04 to 14.04. When I click the "Lock" button from status bar, it will show the new locked screen which looks like the unity-greeter. Then I use the same command as before:

export DISPLAY=:0    
gnome-screensaver-command -d

Nothing happens~ I can't unlock the screen by command.

It looks like a bug in Ubuntu. https://bugs.launchpad.net/ubuntu/+source/gnome-screensaver/+bug/1307163

But is there any workaround to solve this problem?

[update]

I found if we use lock screen command from ssh

export DISPLAY=:0
gnome-screensaver-command -l

it will show the gnome classic screensaver just like Ubuntu 12.04. And use command gnome-screensaver-command -d can unlock the screen.

So is there a way to switch to gnome classical screensaver when click the lock button in status bar?

PS, I have tried CompizConfig Settings Manager, there is not option about changing the lockscreen~~

lee
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3 Answers3

0

A workaround would be to use an alternative screensaver, for example the classic linux xscreensaver. this can be deactivated from command line with 

xscreensaver-command -deactivate
Julian Berger
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  • Actually I do not want to use other screensaver. Is there a way to use the gnome classical screensaver? When I use command `gnome-screensaver-command -l` via ssh, it will show the normal gnome classical screensaver. Also I can unlock it via `gnome-screensaver-command -d`. But when I press Lock button, it will show the Unity screensaver. – lee Dec 22 '16 at 02:46
  • in that case maybe this will help you? http://askubuntu.com/questions/457204/how-can-i-lock-the-screen-using-the-new-lockscreen-from-the-command-line – Julian Berger Dec 22 '16 at 13:53
  • It won't work if screen is locked – 0andriy Dec 28 '20 at 17:09
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To lock the screen via terminal (for Ubuntu 14.04 and 16.04) I use:

dbus-send --type=method_call --dest=org.gnome.ScreenSaver /org/gnome/ScreenSaver org.gnome.ScreenSaver.Lock

Therefore to unlock it this would work:

dbus-send --type=method_call --dest=org.gnome.ScreenSaver /org/gnome/ScreenSaver org.gnome.ScreenSaver.Unlock

Unfortunately I don't have SSH installed to test it. I can test it from the Terminal when the screen is already unlocked and it gives no error message.

I did find another post where this is supposed to work:

dbus-send --session --dest=org.gnome.ScreenSaver --type=method_call --print-reply --reply-timeout=20000 /org/gnome/ScreenSaver org.gnome.ScreenSaver.SetActive boolean:false

The advantage claimed here is that it doesn't ask for a password to unlock the screen. The full thread is here: (Unlock gnome-screensaver instead of deactivating)

Community
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WinEunuuchs2Unix
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  • Yes, you are right. But the question is if you unlock screen via **Lock button on status bar**, then the use the two unlock commands you mentioned won't work. These two unlock commands only works if the lock screen is **gnome classical screensaver**. But when click Lock button on status bar, it will use the new **Unity screensaver**. So I update my question: ***Is there a way to change the original way Lock button clicked, and change it to use gnome classical screensaver***. – lee Dec 22 '16 at 04:00
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Not sure how to switch to gnome-classical screensaver, however the gnome-screensaver-command bug workaround definitely works:

First, enable on-screen keyboard:

gsettings set org.gnome.desktop.a11y.applications screen-keyboard-enabled true

The on-screen keyboard appears when you first sign-in but you can close it.
Lock the screen (needs to happen after enabling on-screen keyboard)
Now gnome-screensaver-command -d works to unlock the screen.

Should work with 14.04 from ssh:

export DISPLAY=:0
gnome-screensaver-command -d

For 16.04, need to set dbus session also:

export DISPLAY=:0
export $(cat /proc/`pidof compiz`/environ | tr '\0' '\n' | grep DBUS_SESSION_BUS_ADDRESS )
gnome-screensaver-command -d

Or better yet, just use loginctl which doesn't need any workaround:

loginctl unlock-sessions
lemonsqueeze
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