Archive:Getting Started/Run/Nested Session

From KDE TechBase
Revision as of 12:51, 31 July 2012 by KennethMartinez (talk | contribs) (minor updates)



Nested KDE 4 Session

Nested

Instead of using a full-blown new X session for developing software you can use Xephyr to run your development build of KDE 4 in a session parallel to your normal working session.

You can also do this with xnest, but as xnest cannot handle extensions like Render many people prefer Xephyr.

Note
In some cases Xephyr/xnest will make the keyboard work incorrectly because of bug:19365. The workaround is to run KDE on a standalone X as described below.


Assuming you setup your build environment following the instructions in Getting_Started/Build/Environment, simply put the following script in ~/kde/src/run_kde_nested.

#!/bin/bash
Xephyr :1 -screen 1024x768 &
sleep 3
export DISPLAY=:1
dbus-launch $KDEDIR/bin/startkde

Make this file executable. Entering the ~/kde/src directory should set up the required environment variables, so do that before running the script.

You can also use Xephyr with KDM via the Xdmcp protocol and simply a new KDE 4 session to KDM.

On Kubuntu, you can enable it by changing

[Xdmcp]
# Whether KDM should listen to incoming XDMCP requests.
# Default is true
Enable=false

in /etc/kde3/kdm/kdmrc to

[Xdmcp]
# Whether KDM should listen to incoming XDMCP requests.
# Default is true
Enable=true

Adjust your /etc/kde3/kdm/Xaccess to allow your local machine access. Additionally you should make sure to set up a port blocking policy on all external interfaces for the Xdmcp port if you are doing this on a laptop or a PC in an untrusted environment.

If you are done, simply launch Xephyr:

Xephyr -query localhost :1 -host-cursor -screen 1024x768&

where -host-cursor tries to reuse the host's cursor and -screen sets the screen dimensions.

Note
If you get lots of refused connection errors, you might want to use the -ac option of Xephyr. When I tried to launch an application into the Xephyr instance, but I received 3-4 "No protocol specified", after finally saying "could not connect to X Server :1". The below code fixed it for me. It only happens when I am crossing users though, as opposed to doing it all in my main user.


Xephyr -ac :1&

Another option to try if you get lots of refused connection errors is you may need to grant access to your kde-devel user to your X server. Do that using:

xhost +local:kde-devel

If you do not have Xephyr, you can also use Xnest:

Xnest -ac :1& export DISPLAY=:1



You may run into this error:

Call to lnusertemp failed (temporary directories full?)
  Check your installation."

If so, try this:

mkdir /var/tmp/kde-devel-kde4

The above code assumes you work with user kde-devel.


Microbial Oasis Discovered Beneath the Atacama Desert

Two metres below the surface of the Atacama Desert there is an oasis of microorganisms. Researchers from the Center of Astrobiology (Spain) and the Catholic University of the North in Chile have found it in hypersaline substrates thanks to SOLID, a detector for signs of life which could be used in environments similar to subsoil on Mars.

[Microbial Oasis Discovered Beneath the Atacama Desert]

[GoodvilleNews.com - good, positive news, inspirational stories, articles]

10 Keys to Happier Living

Action for Happiness has developed the 10 Keys to Happier Living based on a review of the latest scientific research relating to happiness. Everyones path to happiness is different, but the research suggests these Ten Keys consistently tend to have a positive impact on peoples overall happiness and well-being.

[10 Keys to Happier Living]

[GoodvilleNews.com - good, positive news, inspirational stories, articles]

Authors Nominate Top Books of All Time

In 2002, the Norwegian Book Clubs gathered 100 authors from 54 countries and asked each one to list the 10 best works of fiction of all time. The authors responded and this list was created. The titles are arranged alphabetically by author name, so no one book stands above any other. The following list is the groups selection of the worlds 100 best books.How many have you read?

[Authors Nominate Top Books of All Time]

[GoodvilleNews.com - good, positive news, inspirational stories, articles]

Rats Walking Again After Spinal Cord Injury

Scientists in Switzerland have restored full movement to rats paralyzed by spinal cord injuries in a study that spurs hope that the techniques may hold promise for someday treating people with similar injuries.

[Rats Walking Again After Spinal Cord Injury]

[GoodvilleNews.com - good, positive news, inspirational stories, articles]

Awakening Our Collaborative Spirit

The physicist, David Bohm, while researching the lives of Einstein, Heisenberg, Pauli and Bohr, made a remarkable observation. Bohm noticed that their incredible breakthroughs took place through simple, open and honest conversation. He observed, for instance, that Einstein and his colleagues spent years freely meeting and conversing with each other.

[Awakening Our Collaborative Spirit]

[GoodvilleNews.com - good, positive news, inspirational stories, articles]