Instructor notes for using the lab computers

Information about the physics lab, including these instructions, can be found on the lab web page http://www.geneva.edu/~bvds/lab. Information about the computers and instructions for recovery after a hard disk failure on the file server jael can be found at http://www.geneva.edu/~bvds/computing/build.html.

Do not turn the computers off. Do not reset the computers.
When you are done, you need to log out. The computers should all be logged out at the end of the lab.
The following must be done as root. To switch between the window system and a terminal console, use Ctrl-Alt-F1 and Ctrl-Alt-F7. Then you can easily log in as root.
If the window system freezes, restart the window system using init 3, wait a few seconds, then init 5.
If a student completely messes up the luser account, luser should log out and replace the files rm -r -f /lhome; cp -a /usr/local/etc/skel /lhome.
Use passwd luser to change the luser password.
Sometimes the printer queue on abimelech doesn't work. Use service cups restart to restart the printer queue. If this doesn't help, use lpq and lprm to remove the offending print job.
It is good to periodically check the log files on the server jael. Use less /var/log/messages to do this.
The server jael sends out a daily logwatch digest via email. To have this sent to you, set the root alias in /etc/postfix/aliases (near the end) and run newaliases.

Here is some general advice to get you started with UNIX:

Right-click on the desktop to get a shell window.
Mathematica is only installed on the machine bvds. In a shell window, type ssh bvds to log onto bvds. Type mathematica & to get the notebook version or type math to get the terminal version. (The & creates a detatched process so you can still use the shell window.) To enter a command in Mathematica, you have to use the Enter key on the corner of your keyboard. The Mathematica book can be found in the lab.
My favorite spreadsheet program is Gnumeric. You can start this program by typing gnumeric & in a shell window.
My favorite text editor is Emacs. Start by typing emacs & in a shell window.
The fortran compiler is run using the command g77; C is gcc; and C++ is g++.

Other useful commands:

`ls`	list directory contents
`cd`	change directory
`rm`	delete a file. `rm *.log` will delete all files that end with ``.log''
`mv`	move a file
`cp`	copy a file
`lpr`	print a file. You can also print from emacs. The default printer `lab` is already set.
`xeyes`	you'll see

Also:

`~`	is your home directory
`.`	is the directory you are now in
`..`	go up one directory level
`*`	wild card (matches any name). Thus `ls *.f` lists all files that end with ``.f''

If you want to find out about a command, say ls, then type man ls or type info ls.