How do I lock the screen from a terminal?

Question

I am using Ubuntu 12.04. Is there any way to lock the screen or session from a terminal command or script?

Solution 1

Simple:

gnome-screensaver-command -l

The following can also work, if the screensaver is set to lock when activate (see screensaver settings), since the command activates the screensaver:

gnome-screensaver-command -a

You can add an alias to the command by editing the file .bashrc (or .bash_aliases) in your home directory:

gedit $HOME/.bashrc

and adding the following line:

alias lock='gnome-screensaver-command -l'

Then from terminal:

source .profile

This will activate the alias. From now on, the alias lock in a terminal will have the effect of locking the screen.

Solution 2

In addition to what January said, this also works:

gnome-screensaver-command --lock

or

gnome-screensaver-command -l

According to the gnome-screensaver-command man page...

-l, --lock                 Tells the running screensaver process to lock the screen immediately
-a, --activate             Turn the screensaver on (blank the screen)

For further clarification, here is another question/answer (also by January) which describes the differences between invoking the lock and activating your screensaver:

Difference between gnome-screensaver-command -a and gnome-screensaver-command -l

Solution 3

Starting in Ubuntu 14.04, Unity's lock screen no longer uses gnome-screensaver. The command gnome-screensaver-command -l will still work in most cases, but see this question for exceptions.

If that command does not work (say, for instance, that gnome-screensaver is not installed), bringing up the proper Unity lock screen (not the greeter where you can switch users) can be done via this command in a terminal:

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

Solution 4

Please install vlock. Then you can switch to a VT (text terminal, using Ctrl+Alt+F1) and run

vlock -a -s

This works whether you have X11 running or not.

Solution 5

$!(sleep 10s ;  xset dpms force suspend) & xdg-screensaver lock

this starts the screen saver in locked mode and then puts your display in standby. sweet and simple, no sudo. command line or shell script works fine. i use this for a keyboard hotkey. Ubuntu Mate 15.10

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Comments

[mx7]

Thank you . now I'm in mobile . I'll try and let you know

[mx7]

looking nice . ok I'll try and let you know . thank you .

[mx7]

ok its looking good , but suits only for TTY .

[January]

Sorry, I had to modify your changes. (i) no need to use sudo (ii) better .profile than .bashrc, since .bashrc gets called every time you create a new shell and (iii) alias works only when called from shell.

[mx7]

ok now its looking good , you like the idea ?

[January]

sure. I usually lock with a single keypress, though, makes it quicker when leaving the office for a coffee.

[mx7]

I think if we add more answer about creating a custom-shortcut key will improve , what do you say ?

[Bohr]

For Tmux, set-option -g lock-command vlock (require vlock)

[pbhj]

dm-tool lock seems better as that just locks the screen. "switch to greeter" ended my session when I tried it.

[jippie]

Works on Kubuntu 16.04 too.

[zamnuts]

ty for xdg-screensaver lock, +1, however your answer didn't do the trick on ubuntu 16.10 gnome 3, i use: xdg-screensaver lock && sleep 2s && sudo pm-suspend. i have this aliased, and also with pm-suspend in my sudoers.d: yourusername yourhostame = NOPASSWD: /usr/sbin/pm-suspend

[Dinesh]

Using this in a cron job does not work? Script : lock_script.sh #!/bin/sh dm-tool switch-to-greeter Cron-job : 42 9 * * * /home/user/lock-script.sh

[Rolf]

dm-tool is not very safe. Not on my system, anyway. Try going to a text TTY (Alt-Ctrl-F2) then back to your X TTY (Ctrl-Alt-F7 for me). It makes the lock screen disappear!

[Brad]

This was definitely the best - because the other "screen-saver" based ones gave you a different "lock screen" which ONLY allows you to enter a password (no changer-user, logout, restart, etc). Also: May want to do stuff like: DISPLAY=:0 sudo -u username xdotool key Ctrll+alt+l

[friederbluemle]

Version 2.0.4 of vlock does not seem to have the -s switch anymore. Just running vlock -a works fine.

[Timo]

In Version 2.2.2, the s flag exists and is defined as -s or --disable-sysrq: disable SysRq while consoles are locked to prevent killing vlock with SAK. SAK is the secure attention key, which protects against trojan password capturing according to kernel.org. In a tty the a flag is enough to password protect.

[Timo]

ERROR: Unknown command 'lock' in Lubuntu 18.4. LTs

[Amin]

Thank you - this works without installing gnome screen save

[holms]

holms@debian:~$ xdg-screensaver lock ERROR: Unknown command 'lock'

[holms]

nothing happens in dwm

[Eric]

This works on Mint mate 20.1, which is based on Ubuntu 20.04.

[Eric]

Doesn't work, on my Linux mint mate, instead xdg-screensaver lock works.

[electrovir]

The accepted answer uses a command that I don't even have installed on Ubuntu 20.04. This one works without installing anything extra.

[aasutossh]

@user218867 perfect for Pop_OS too. Another command is loginctl lock-session. To unlock the screen loginctl unlock-session.

[Admin]

gnome-screensaver-command doesn't appear to be installed but xdg-screensaver lock confirmed to work on Ubuntu 22.04.