I've been trying to figure out how to lock the screen in XUbuntu 16.04 and I can't seem to make anything work. Various posts suggest using the settings under 'Power Manager' and 'Light Locker Settings', which have selectors to enable and disable the screensaver, and I've tried all possible combinations of them, but none of them do anything.
Other places suggest running
xflock4 or hitting
ctrl-alt-del (which on the keyboard shortcuts runs xflock4), but that also does nothing. There's also no documentation for
xflock4 (man xflock4 says "No manual entry" and
xflock4 --help does nothing.)
After poking around things for awhile, I fould
dm-tool which has a
lock option. Running
dm-tool lock from a terminal successfully locks the screen. I can also set the keyboard shortcuts to make ctrl-alt-del run
dm-tool lock, so I can now lock the screen with a key combo.
However, I still can't figure out how to get it to lock the screen after a timeout...