37

When I am running some software using sudo command it showing error like 

cannot connect to X server

For example if I run the following command: 

$ sudo gedit /etc/profile

I am getting following command

(gedit:6758): WARNING **: Command line `dbus-launch --autolaunch=84b871d735f31ffe014dc9ba00000009 --binary-syntax --close-stderr' 
exited with non-zero exit status 1: 
Autolaunch error: X11 initialization failed. 
Cannot open display:
Run 'gedit --help' to see a full list of available command line options.

Or if I am running super-boot-manager I am getting following error 

buc: cannot connect to X server

Please help.

Peachy
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Apurba
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  • Where do you run super-boot-manger from? – Thor Aug 15 '12 at 09:49
  • First I have tried to run super-boot-manager directly from unity luncher, it did not worked. Then I have tried it from terminal, then I got those error massage. – Apurba Aug 15 '12 at 13:21
  • As in a terminal within the graphical user environment? What does: echo $DISPLAY say? You should run it without sudo as super-boot-manager runs sudo internally. – Thor Aug 15 '12 at 15:23
  • echo $DISPLAY is giving :0.0. And I am not running super-boot-manager as sudo. I am running just using command super-boot-manager from terminal. – Apurba Aug 16 '12 at 19:36
  • also If I am not using the part DISPLAY=$DISPLAY in command gedit is not opening using sudo – Apurba Aug 16 '12 at 19:40
  • buc might be running as a different user, try removing the X restrictions with xhost +. – Thor Aug 16 '12 at 19:51
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    Finally the problem is solved. I have just added the line: Defaults env_keep="DISPLAY XAUTHORITY" at the end of visudo. Thanks to all, specially @Thor for kind help. – Apurba Aug 17 '12 at 08:03
  • Nice solution, forgot about sudoers env_keep. – Thor Aug 17 '12 at 08:09
  • You should add your solution as an answer, it would make it easier for others to find. – Thor Aug 27 '14 at 09:34
  • I've made a script for this purpose: gist.github.com/wachambo/bd22e12db2d5a46dc109bd0d553733be – Alejandro Blasco Oct 09 '18 at 12:42
  • Can you please hep me with this issue https://stackoverflow.com/questions/71464381/java-runtime-execution-not-working-in-cron-job-reboot-showing-error-unable-to – rickoonidioser Mar 20 '22 at 12:42

4 Answers4

53

You need to allow the root user access to the X server:

xhost local:root

And point the command to the right DISPLAY:

sudo DISPLAY=$DISPLAY gedit /etc/profile
Thor
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20

Finally the problem is solved. I have just added the line:

Defaults env_keep="DISPLAY XAUTHORITY"

at the end of visudo.

To do that you have to run:

sudo visudo

it will open the file then add the above line at the end.

Thanks to all, specially @Thor for kind help

BeastOfCaerbannog
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Apurba
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    Defaults env_keep="DISPLAY" works for me. – sugab Mar 09 '15 at 16:28
  • I have been searching high and low for this answer forever. I wish I could upvote both of you multiple times for your answers. Thank you so very much! :) – Ev- Dec 28 '16 at 06:38
5

Supplementing @Thor's answer, run:

xhost local:root

before sudo gedit. To make this permanent, add the line

xhost local:root

to the ~/.xinitrc 1 file. Create the file if it doesn't exist.

1 https://askubuntu.com/a/720120/452398

BeastOfCaerbannog
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adabru
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0

set DISPLAY and XAUTHORITY variable environment before running your scrip. for example in systemctl service file:

[Unit]
Description=Start Clock

[Service]
Environment=DISPLAY=:0
Environment=XAUTHORITY=/home/pi/.Xauthority
ExecStart=/usr/bin/python3 /home/pi/clock.py
Restart=always
RestartSec=10s
KillMode=process
TimeoutSec=infinity


[Install]
WantedBy=graphical.target
Hamid
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