Contents 1 Using the normal shell with sux 2 Using the normal shell without sux 3 Using SSH 3.1 Passwordless login 3.2 The SSH desktop file Using the normal shell with sux For this method, the tool sux (http://fgouget.free.fr/sux/sux-readme.shtml) is required. sux is available on most distributions. Otherwise you could rely on the normal shell without sux method below. sux allows you to change to another user with an implicit managing of the X forwarding details (authentication and DISPLAY exporting) in a clean and simple way. To login, type sux - kde-devel All environment variables and everything else should be set up correctly by your .bashrc. To start an application, simply type it's name; for example kwrite Note If you get errors about missing mimetypes or such, try running the following:unset XDG_DATA_DIRS ; kbuildsycoca4 Using the normal shell without sux The simplest method to launch KDE 4 applications is using su to login as the kde-devel user and then simply start any KDE 4 application from command line. To login, type su - kde-devel and then, after entering your password export DISPLAY=:0 Note Exporting the DISPLAY variable is necessary so that the KDE 4 applications appear on your normal KDE 3 desktop. All environment variables and everything else should be set up correctly by your .bashrc. To start an application, simply type it's name; for example kwrite Note If you get errors about missing mimetypes or such, try the following: run unset XDG_DATA_DIRS ; kbuildsycoca4 Note If you get an error about not being able to connect to an X server, be sure to issue sudo xhost +local:kde-devel as your regular KDE 3 user to ensure that the application can connect to your current X session. Although your X server should accept incoming TCP connections, this is often switched off as a distribution default (like with Kubuntu Feisty). When using kdm you must edit /etc/kde3/kdm/kdmrc as root and make sure it does not contain: ServerArgsLocal=-nolisten tcp Once you have fixed this, you will need to restart your X server. The xhost command should no longer return an "unable to open display" error. For convenience, you should put this in the Autostart of your regular user. To do this, create a new file in the $HOME/.kde/Autostart directory of your regular user with the following content: #! /bin/sh xhost +local:kde-devel Make sure that the new file is executable by using chmod +x on it. If you'd like to find out more about the security issues involved with using xhost, see this article Using SSH The simplest way to run a KDE 4 application with SSH in your current desktop environment is to get an X-aware shell prompt as the kde-devel user like this: ssh -X [email protected] Now you can launch KDE apps as usual, for example: kwrite The two lines can be conveniently combined: ssh -X [email protected] kwrite Note If this gives you any errors, try the troubleshooting tips from the section above. If you receive something like "kwrite: cannot connect to X server", open /etc/ssh/sshd_config and enable the "X11Forwarding" key. Restart sshd and it should work fine. Passwordless login Before anything serious can be done using this method, a passwordless login needs to be set up. To start, run the following command as the regular desktop user: ssh-keygen -t rsa Hit enter three times to accept the path of ~/.ssh/id_rsa and an empty passphrase. Now, copy the single line in ~/.ssh/id_rsa.pub that's printed after running this command: cat ~/.ssh/id_rsa.pub After that line is copied, ssh back into the kde-devel user and put the copied line in the file $HOME/.ssh/authorized_keys: ssh -X [email protected] $HOME/kde/bin/kwrite \ $HOME/.ssh/authorized_keys Paste in the line, save the file, and quit KWrite. Next make sure $HOME/.ssh/authorized_keys has the correct permissions: ssh [email protected] chmod og-xrw ~kde-devel/.ssh/authorized_keys Now try running KWrite again with the same SSH command; you shouldn't have to enter a password anymore: ssh -X [email protected] $HOME/kde/bin/kwrite Warning Using a passwordless SSH login has certain security risks, so make sure you protect your ~/.ssh/id_rsa file by restricting access to it with chmod og-xrw ~/.ssh/id_rsa (although the file should have these permissions when it is created) The SSH desktop file If you want to be able to launch apps more easily than running them with an SSH command from the command line, one way is to create .desktop files that ssh into the other account. Note This will only be useful if your desktop environment supports .desktop files, but at least KDE and GNOME do. You can start with an existing .desktop file as a template (like one from your desktop) or you can make one from scratch. The main idea is to prefix the command being run with this string: ssh -X [email protected] $HOME/kde/bin/ A simple .desktop file that runs KWrite would have the following contents: [Desktop Entry] Categories=Qt;KDE;TextEditor; Comment= DocPath=kwrite/index.html Encoding=UTF-8 Exec=ssh -X [email protected] /home/kde-devel/kde/bin/kwrite %U GenericName=Text Editor Icon=kwrite InitialPreference=8 MimeType=text/plain Name=KWrite (kde-devel) Path= StartupNotify=false Terminal=false TerminalOptions= Type=Application X-DBUS-StartupType=Multi X-DCOP-ServiceType=non X-KDE-StartupNotify=true X-KDE-SubstituteUID=false X-KDE-Username= Tip Apps launched using SSH like this don't trigger the correct launch responses, so you probably want to disable "launch feedback" for your .desktop files Note In order to create a .desktop file for a KDE 4 app by using this pattern, the app's package will have to have been installed into ~/kde/bin using the cmakekde command Retrieved from "https://techbase.kde.org/index.php?title=Archive:Getting_Started/Run/Shell&oldid=74126" Categories: Noindexed pagesKDE4 This page was last edited on 31 July 2012, at 15:55. 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