xset: unable to open display

Question

For the longest time after about 5 minutes my screen would blank out. Now the screen will go blank after 5 minutes but then 2 seconds after that it will light up white and keep the laptop backlighting on. I didn't change any settings to my knowledge it just happened randomly after powering it on one day and has occurred since then.

I wish to resort back to blanking the screen out completely since I leave this computer on all the time and it's hard to sleep with a huge white light all the time.

xset dpms force off just yields me:

xset:  unable to open display ""

score 15 · Answer 1 · edited Aug 26 '14 at 07:18

15

You need to tell xset which display to use:

export DISPLAY=:0
xset q

edited Aug 26 '14 at 07:18

Anon

12,389

answered Aug 26 '14 at 06:35

mariocosmi

157

5

export DISPLAY=:0 > xset q after that I have ' unable to open display ":0" '
– KeyTrap Jun 12 '15 at 12:58
Had same problem when was trying to access monitor remotely with user other than logged in. – Nikolay Ruban Dec 11 '15 at 11:51
3

Then I get xset: unable to open display ":0" – yode Jul 02 '17 at 03:57
export DISPLAY=0 instead. It should work – KRoy Oct 28 '18 at 15:06
Neither of the methods works in systemd foked process. – Seff Aug 23 '20 at 19:09
For me a combination of sudo & running the normal command worked. Combination of export DISPLAY=:0 and sudo xset q. Pretty weird. – TimNode Aug 02 '21 at 00:40

score 3 · Answer 2 · answered May 09 '16 at 21:37

3

Try vbetool instead xset:

sudo vbetool dpms off

It's works fine for me.

answered May 09 '16 at 21:37

Jouri Kondratiev

31

2

Sorry I got the error "Real mode call failed" – bitdancer Oct 27 '19 at 14:51
2

I got "Failed to initialise LRMI (Linux Real-Mode Interface)." – Anh-Thi DINH Jun 23 '22 at 07:52

xset: unable to open display

2 Answers2