Linux and JUDE Community Lab

CS 245

Sept. 19, 2010

Login to a Windows workstation and start a GNOME session on phoenix using NX Client for Windows. Login to phoenix. GNOME is a GUI interface, required for JUDE Community and Eclipse.
Linux is case sensitive -- be careful when entering username and password!
You may install the NX Client software on your own workstation. Check here
(http://phoenix.goucher.edu/~kelliher/nxclient/). for details.
(If you only need shell access, you could start the SSH Secure Shell Client software on a lab workstation. Click the Quick Connect button and enter the Host Name
(phoenix.goucher.edu) and User Name information requested for the dialog box which pops up. Click the Connect button and then enter your password into the next dialog box.
A brief bit of documentation on SSH Secure Shell is available here
(http://phoenix.goucher.edu/~kelliher/SSH/). In particular, you can request a copy of the software for educational use.
There is also a Java SSH client applet available on phoenix here
(http://phoenix.goucher.edu/ssh/). )
You need to open a shell. Open the Applications menu, go down to System Tools and choose Terminal.
A window will open and you will now have a command line prompt on phoenix similar to this:
```
[kelliher@phoenix ~]$
```
You type a command and then press Enter to run it. You can edit a command before you run it by using the arrow keys to navigate the command line.
If you've just logged in for the first time, you'll probably want to change your password. Due to its exposure to the Internet, phoenix is picky when it comes to accepting new passwords. You may want to review http://phoenix.goucher.edu/password.shtml for some advice on selecting a good password. When you're ready, run the passwd program to change your password:
```
passwd
```
In order to enforce the use of strong passwords, I run password cracking software from time-to-time. If this software discovers your password, you will receive a ``nastygram'' from me and your account will be disabled until you see me to select a strong password.
Using gedit, create a file named name containing your name. Print the file in HS 149 using gedit. Alternatively, once you have saved the file, you can use the lpr command in the shell to print the file:
```
lpr -P hs149ps name
```
The file should be printed on the printer in HS 149. The default printer is the printer in the X Lab, hs123ps.
Using the shell, remove the file you just created:
```
rm name
```
Unlike Windows, once you remove a file in Linux, it is gone for good. So be careful!
The file can also be removed by using the File Browser, which is available under the Applications menu. The File Browser is similar to Windows Explorer.
Change directories to /etc:
```
cd /etc
```
You can verify that you're where you think you are by running the print working directory command: pwd.
Using the ls command, list the files in /etc. Too many to fit on a single screen? Pipe the output to the paging program:
```
ls | less
```
Repeat again using the -l option to ls What's the difference?
Change directories back to your home directory (run cd without an argument). List the files in your home directory. Try again using the -a option. What's the difference? Read the man page for ls to read about these two options and find what other options are available:
```
man ls
```
Using the mkdir command, create a sub-directory within your home directory: foo. You can guarantee the the contents of the directory are private by using the chmod command:
```
chmod go= foo
```
Use ls -l to verify. Finally, remove the directory with rmdir:
```
rmdir foo
```
and use ls to verify its removal. As a safety precaution, rmdir only works on empty directories.
It is a good idea to create a new directory each time you start a new assignment or project, so that you don't clutter up your home directory. Using sub-directories for your assignments also helps keep others out of your files.
It's time to start JUDE Community. Run the command
```
jude &
```
(The & runs JUDE Community in the background, letting you continue to type shell commands.)
Create a new file for your ``project'' (look under the File menu).
Experiment with creating a couple use case and class diagrams. You'll find a lot of JUDE Community documentation on the course web site.
If you'd like some examples to guide you, here's a use case and a class diagram:

$\includegraphics[width=4.5in]{Figures/useCaseDiagram.eps}$

$\includegraphics[width=4.5in]{Figures/classDiagram.eps}$
Export your diagrams as PNG images (look under the Tool menu).
If you now wanted to attach the exported diagrams to your project wiki, the easiest thing to do at this point would be to open a Web browser from your X session, browse to your project, and attach the diagrams.
Save your project.
When you're finished, exit from JUDE Community and use the exit command to close your shell. Open the Actions menu to logout from phoenix.

Thomas P. Kelliher 2010-09-22

Tom Kelliher