How to gain Remote Access to the CVL over the Internet

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A (very brief) introduction to graphics on Linux/Unix machines like the CVL

While working on a project from home or from another location on campus, it is possible to access the programs contained in the CAD and Visualization Lab. This generally comes in either command-line form directly, or as a graphical application that is launched via the command-line. The command-line is also called a "shell" in Unix-speak. There are many different tutorials available on the net to familiarize yourself with the basic file operations that can be performed via the command-line shell. A few examples can be found in this UNIX / Linux Tutorial for Beginners, or this Introduction to the Unix Shell. Fortunately, not very many of these command-line utilities are required to access and use the software installed in the CVL. Generally, only the basics of listing the files (ls) in your home directory, making project directories (mkdir), moving files in and out of those directories (mv) are only basic operations required.

The program called "Secure Shell" or SSH is the supported way of connecting to a command-line shell on the CVL from another machine. This establishes a secure, encrypted connection to a command shell ona remote machine, has wide support on many operating systems, and even allows file transfers over the same encrypted channel.

Applications on Unix are not restricted to command-line programs. The Unix standard for graphical applications is called "X-windows," or just "X" for short. In fact, the graphics capabilities of this X-windows system are much more flexible than in Windows or MacOS because they allow for interacting (viewing windows, buttons, pointing, clicking, etc) on a different machine than is actually running the application. All that is required to do this is a network connection between the two, and what's referred to as an "X-server" on the machine that the user physically viewing the windows and manipulating the mouse. This "client/server" naming convention seems backwards in that the "server" runs on the workstation (e.g. your Windows laptop), and the "client" is the application running on the CVL (e.g. Matlab). Linux clients generally have this X-server installed, but Windows users have to install one if graphical access to the CVL is required.

Accessing the CVL Remotely from a Windows Operating System

In order to accomplish this you must have a SSH client and a X windows server installed on your Windows machine. ECE supports PuTTY as our SSH client and Cygwin/X as our X windows server.

To download, install, and setup these programs follow these short tutorials.

PuTTY tutorial
Cygwin/X tutorial

At the end of the Cygwin Tutorial you will be given the instructions on how to access the CVL remotely. For step-by-step instructions, see RemoteAccess.docx.

In order to copy files (e.g. Matlab scripts, data files for processing, etc), you can transfer files to and from your CVL account using a program similar to SSH for transferring files. One very simple application that can be used is called WinSCP. The WinSCP homepage has either a full installation package, or just a single executable file on its download page.

Accessing the CVL Remotely from a Unix Based Operating System

To access the CVL from a Unix system just open a terminal and type:

  ssh -X

Use the user name and password that you created from the CVL Account creation page.

To copy files to your home directory on the CVL use the command

  scp -r myfile

or, to get "myfile" from your home directory on the CVL, the command

  scp -r ~

will copy them to your home directory on your local machine.

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