Motif and X-Windows

Remote Windows


It is possible to execute a Motif application on a computer around the corner or around the world and redirect the input and output for the application to your workstation. There are files located on the Science Cluster to help you position and display windows from a remote VMS system. Follow these steps to use them:

  1. Copy the x.com file to your home directory, for example:

$ copy stscic::sys$local:[windows]x.com sys$login:x.com
If your workstation is not part of the Science Cluster, you need to take the following steps to create the same environment on your workstation:

$ copy stscic::sys$local:[windows]xterm.com sys$login:xterm.com
$ copy stscic::sys$local:[windows]getcolor.com sys$login:getcolor.com
$@SYS$LOCAL:[WINDOWS]XTERM `P1 `P2
to:

$@SYS$LOGIN:XTERM `P1 `P2
  1. From one of the workstation windows, have the remote system execute the x command file and create the display on your workstation by using this command:

$ type airy::"0=x" 
  1. You may need to set your workstation security. The following error messages indicate a security problem:

-RMS-E-ACC, ACP file access failed
-SYSTEM-F-INVLOGIN, login information invalid at remote node
Xlib:  connection to "BABEL::0.0" refused by server
Xlib:  Client is not authorized to access server
%SYSTEM-F-CONNECFAIL, connect to network object timed-out or failed
%SYSTEM-F-NOPRIV, no privilege for attempted operation
If you see these messages, you must set your workstation security to allow the remote system to display to your workstation. To do this:



Figure 6.9: Security Options Window

  1. In addition to workstation security, you must have a proxy in place. The proxy is what makes it possible to avoid having to enter your username and password when running network commands. Proxies are established by the system managers. If error messages persist, contact your system manager.

Now that you know how to pop open a DECterm window on a remote system, you might like to do this from a menu item instead of typing it each time. You can add the appropriate command to your Applications menu. In addition, this new application could be added to your Automatic Startup...

Follow these steps to create a new menu item:

  1. Select the "Menus..." submenu item of the Session Manager Options menu.

  2. In the Menus window, Figure 6.10, click on the DCL command entry box and enter the DCL command. For example:

    type EOTVOS::"0=x"
  1. Click on the text entry box above the DCL Commands entry box. Enter the name you wish to call this application. For example:

    DECterm EOTVOS
  1. Click on the up arrow button. Notice that the new menu item is added to the Items Names list.



Figure 6.10: Adding Applications: the Menus Window

To add this new menu item to the Applications menu, follow these steps:

  1. Select "Applications" in the Menu Names list.

  2. From the Items Names list, select the menu item to be added. In this example, "DECterm EOTVOS".

  3. Click on the arrow button that appears. Notice the new menu item is added to the Applications menu.

  4. Finally click on the [OK] to save these changes. Don't forget to save these changes to your Session Manager.

You can also display a Unix window on your VMS workstation. This procedure it a little more involved. See your system manager for details.

If you try to run an application in a remote window, you might see an error message like this:

X Toolkit Error: Can't Open display
This usually means that the display is incorrectly set. To see where the output from a DECwindows application will be displayed, type SHOW DISPLAY. The node listed must be the name of the workstation that you are physically using. The following command is an example of to set the node:

$ SET DISPLAY /CREATE/NODE=athena

Opening VMS Windows from Unix

If you are logged into a Unix workstation and you'd like to run a Motif
application on a VMS system, with input and display on your local display, you can do so as follows:

  1. Give the remote VMS host permission to write to your local workstation using the Unix xhost command. The syntax is:

    % xhost +node
  1. Log in to the remote VMS system using telnet. (Make sure it is a system with Motif installed).

  2. Set the display to the name of your local Unix workstation, and make sure you specify that the transmission protocol is TCP/IP. The syntax is:

    $ SET DISPLAY/CREATE/NODE=node.domain/TRANS=TCPIP
  1. Start the Motif application using the SPAWN command (you could try RUN too, but it will lock your window onto the VMS host until the application terminates). The syntax for using SPAWN is:

    $ SPAWN/NOWAIT/INPUT=NL: application
The process might be clearer by looking at an example. We will show this one using RUN; normally, you will want to replace the RUN statement with a SPAWN statement. Assume that you are logged into the Sun Sparcstation lager.stsci.edu and want to log into the VMS host KEPLER so that you can access Bookreader documentation. Figure
6.11 shows how this is done.



Figure 6.11: Running a Motif Application on a Remote VAX from a Local Sun

Figure 6.9: - Security Options Window
Figure 6.10: - Adding Applications: the Menus Window
Opening VMS Windows from Unix
Figure 6.11: - Running a Motif Application on a Remote VAX from a Local Sun

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