How do I disable the screensaver/lock?

Solution 1:

• 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.

Solution 2:

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.