Using X Windows

The ATNF Visualisation software and some of the PGPLOT devices work via X-windows. For these to work, you must ensure that you have setup your environment to allow communication with your X server. In particular

• You should be working at a workstation running X windows!

• You do not need to run the display tasks on the same computer as the X-windows server. However if you are running on a different machine, then you will need to tell the display software which machine is running your X server.

  If you have connected through SSH, then the SSH client should have, or can be made to automatically configure X-windows forwarding to your local screen. To ensure that X-forwarding is enabled, use the SSH connection command:

  % ssh -X user@remotehost

  Different SSH clients may use -Y or -x to enable X-forwarding; check your man page to determine which is appropriate for your installation.

  If you have connected in another way - telnet for example - then you will need issue the command

  % setenv DISPLAY localhost:0

  to the machine you are running Miriad tasks on. Here localhost is the name of the host machine running X windows. Normally this will be you local workstation. Do NOT just type localhost as this will not work.

• X windows has a simple security feature to prevent arbitrary people drawing plots on your screen. To authorise a particular machine to send commands to your X server, you will need to issue the command

  % xhost +remotehost

  to your local host. Here remotehost is the name of the host machine that you want to grant permission to. For Miriad applications, this will be the host you are running the plotting task on.