Using Xming for Remote Graphics

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• Overview
  • To use graphics on turing from another machine, you need a server for the X protocol, commonly called X-Windows. You can learn more about X at X-Windows in Wikipedia.
  • The term predates Microsoft Windows and has nothing to do with it. The use of the term window for a GUI window existed long before Microsoft created their operating system. The current version of X is X11, so you will sometimes see that term also.
  • If you are running on Windows, Xming is the easiest and best one to get. It is also free and open source.
  • As a security measure, you also have to tell putty that you are willing to have graphics sent back from turing to run on your machine.
  
  
• Getting Xming
• Xming should already be installed on the lab computers.
• If you're running on your own PC, you may need to download and install it first.
  • You can get the software (free and open source) from Xming on SourceForge.
  • Just download and unzip it (all the default options are fine). It will give you an XLaunch icon on your desktop that you can use to start it.
  • If you want more information, you can get it from the Xming web site.


• Using Xming
  • You need to start Xming from the start menu before you start putty.
  • On the putty configuration screen, before you click 'open', do the following two things:
    • Under connection | SSH | auth, check "allow agent forwarding."
    • Under connection | SSH | X11, check "enable X11 forwarding."
  • If you are running on your own machine, you can save a session with those settings.
  • After starting Xming and putty, try running xclock from your putty session on turing. If you see a picture of a running analog clock, then everything is working correctly.
  • Now you can start geany, gedit, or any graphical program of your choice. Use a trailing ampersand if you want access to your terminal session while your graphical program is running.


• Connecting from another linux box
  • If you are connecting from another linux box, you don't need the emulator, just the -X option of ssh to give permission to use the X-server.
  • If you are running on the graphical console of your own linux box, you don't need either putty or the emulator.


• Error messages
  • If you get this error:
         no display name and no $DISPLAY environment variable
    you do not have an X-Windows server running on the machine you are running on, or you have not told putty you want to use X-Windows.
  
  
  • If you get this error:
        Can't open display: localhost:10.0
    you have the correct putty settings but you forgot to start Xming first.


• Emacs
  • You can run emacs either graphically or in a terminal window. The default varies from machine to machine.
  • If you are getting the graphical version (or one of the errors above) and want the other version, use emacs -nw, i.e., "no window".