When I'm watching a film in Mythtv the screen turns to black every 10 - 15 mins and I have to log back into Ubuntu. Very annoying!
How do I disable the black screen / screensaver / logout in Unity?
There no longer seems to be any options to turn the screen saver off as there were in Ubuntu prior to Unity.
Go to System Settings...Brightness and Lock:
The default screensaver idle time is 10 minutes, and the screen is locked once the screensaver activates:
You can adjust the idle time (or disable the screensaver), and also disable the lock:
Simply close Brightness and Lock to apply the new settings.
If you want to wrap your app in a script that takes care of this for you when you launch it (or GUI simply isn't an option), the best command-line solution as of Ubuntu 14.04 is:
To disable the screen blackout:
gsettings set org.gnome.desktop.session idle-delay <seconds> (0 to disable)
To disable the screen lock:
gsettings set org.gnome.desktop.screensaver lock-enabled false
You probably want to add their inverses at the end of the wrapper script to return your system to normal behavior on exit. In such a case, you want to prevent against ungraceful termination (i.e. interrupt, or SIGTERM during system shutdown), so create a function to restore normal behavior and use trap <function> 0 (for bash-type shells) to catch exits and apply the restoration functions.
To disable the automatic screen lock in Ubuntu 14.10 Gnome, these are the necessary steps:
To make this answer more useful as a Google search result for common search terms such as "disable lock screen ubuntu" (how I found this page), I've added this answer to extend the context of this page to include the steps to disable the automatic screen lock in Ubuntu 14.10 Gnome. System Settings (called simply "Settings" in Ubuntu 14.10 Gnome) are organized slightly differently within Ubuntu 14.10 Gnome than as described by the answer listed above, requiring a different user flow.
If the unity gui doesn't work, then you could try using xset
Open a terminal and type:
xset s off
To also prevent the display from blanking and to prevent the monitor's DPMS energy saver from kicking in, add the following:
xset s noblank
xset -dpms
Also try some things here:
https://wiki.archlinux.org/index.php/Display_Power_Management_Signaling#xset_screen-saver_control
Only caffeine extension worked for me in Ubuntu 19.04 to disable automatic screen lock and have manual locking still working.
This is disable locking screen alltogether, so is not good:
gsettings set org.gnome.desktop.lockdown disable-lock-screen 'true'
For me on kubuntu 16.04 (plasma) I have to go to System Settings -> Workspace -> Desktop Behavior -> Screen Locking -> turn off 'Lock screen automatically after'
On kubuntu 18.04 I find, K-menu -> Settings -> System Settings -> etc (see above).
Yet another potentially useful solution, along the lines of caffeine, is xssproxy. From its description in synaptic:
For example Firefox uses the org.freedesktop.ScreenSave D-Bus interface to disable the screensaver when playing videos. This package implements that interface and disables the X built-in screensaver in that case.
Like with caffeine, you'll need to run it when your X session starts.
I found that this works on Ubuntu 18:
# Configure dconf to disable screen lock
sudo mkdir -p /etc/dconf/profile/
sudo tee /etc/dconf/profile/user <<EOF
user-db:user
system-db:local
EOF
sudo mkdir -p /etc/dconf/db/local.d/
sudo tee /etc/dconf/db/local.d/10disable-lock <<EOF
[org/gnome/desktop/session]
idle-delay=uint32 0
EOF
sudo dconf update
On Ubuntu 16.04 you have to go to System Settings -> Screensavers and switch to Settings tab:
Over there you can disable several types of locking.
