How do I automatically set the DISPLAY variable for my current session

Question

I see that  DISPLAY is set to localhost 0 0 if I am running over a vnc server this may not be correct  is there a way to automatically set it in my login script

User · Answer

Here s something I ve just knocked up  It inspects the environment of the last-launched  gnome-session  process  DISPLAY is set correctly when VNC launches a session window manager   Replace  gnome-session  with the name of whatever process your VNC server launches on startup   PID  pgrep -n -u  USER gnome-session  if   -n   PID     then     export DISPLAY  awk  BEGIN FS      RS   0     1   DISPLAY   print  2  exit    proc  PID environ      echo  DISPLAY set to  DISPLAY  else     echo  Could not set DISPLAY  fi unset PID   You should just be able to drop that in your  bashrc file

User · Answer

You ll need to tell your vnc client to export the correct  DISPLAY once you have logged in  How you do that will probably depend on your vnc client

User · Answer

do you use Bash  Go to the file  bashrc in your home directory and set the variable  then export it   DISPLAY localhost 0 0   export DISPLAY  you can use  etc bashrc if you want to do it for all the users   You may also want to look in    bash profile and  etc profile  EDIT   function get xserver          case  TERM in        xterm               XSERVER   who am i   awk   print  NF     tr -d                          XSERVER   XSERVER                             aterm   rxvt                                esac      if   -z   DISPLAY         then     get xserver     if    -z   XSERVER        XSERVER       hostname               XSERVER      unix      then          DISPLAY   0 0             Display on local host      else         DISPLAY   XSERVER  0 0    Display on remote host      fi fi  export DISPLAY

User · Answer

I m guessing here  based on issues I ve had in the past which I did solve    you re connecting to a vnc server on machine B  displaying it using a VNC client on machine A you re launching a console  xterm or equivalent  on machine B and using that to connect to machine C you want to launch an X-based application on machine C  having it display to the VNC server on machine B  so you can see it on machine A    I ended up with two solutions   My original solution was based on using rsh   Since then  most of our servers have had ssh installed  which has made this easier   Using rsh  I put together a table of machines vs OS vs custom options which would guide this process in perl   Bourne shell wasn t sufficient  and we don t have bash on Sun or HP machines  and didn t have bash on AIX at the time - AIX 5L wasn t out yet    Korn shell wasn t much of an option  either  since most of our Linux boxes don t have pdksh installed   But  if you don t face these limitations  you can implement the idea in ksh or bash  I think   Anyway  I would basically run  rsh  machine -l  user   cmd   where  machine  of course  was the machine I was logging in to   user  similarly obvious  though when I was going in as  root  this had some variance as we have multiple roots on some machines for reasons I don t fully understand   and  cmd was basically  DISPLAY  DISPLAY xterm   though if I were launching konsole  for example   cmd would be  konsole --display  DISPLAY    Since  DISPLAY was being evaluated locally  where it s set properly   and not being passed literally across rsh  the display would always be set correctly   I also had to make sure that no one did anything silly like reset DISPLAY if it was already set   Now  I just use ssh  make sure that X11Forwarding is set to yes on the server  sshd config   and then I can just ssh to the machine  let X commands go across the wire encrypted  and it ll always go back to the right place

User · Answer

Your vncserver have a configuration file somewher that set the display number  To do it automaticaly  one solution is to parse this file  extract the number and set it correctly  A simpler  better  is to have this display number set in a config script and use it in both your VNC server config and in your init scripts

[linux] How do I automatically set the $DISPLAY variable for my current session?

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