To the S&B class:

To go directly to the approriate message click on its number: 1,2, 3, 4

Message #1 For the first week of class:

The computers that you will be working with are “clam”, “leinster”, and "hpc". Keywords and phrases are put into double quotes (“) in these messages. Please remember their meanings as I will be referring to them during class.
A “server” is a computer that usually runs all the big programs like gaussview that get “distributed” to all the “client” computers. They get distributed when you log into the server from a client computer. The clients are usually the computers that you are sitting in front of, they run smaller programs like editors or small graphics programs like gnuplot.

The server and the clients usually have the same hard drive so that all your data (in files with names) can be accessed by any one of the server or client computers, i.e. you don't have to "ftp" (file transfer protocol, much like logging into another computer so that you can transfer files back and forth) files.

The "hpc" server  computer is part of the Science Vision Center, made up of the chemistry, computer science, math, and physics departments. Its rather mundane name stands for high performance computer. Its clients are imaginatively named hpc001, hpc002, through hpc012. These SUN client computers are located in Room 424 of the BS Bldg. where class is held. The SUN clients all have the same hard drives as hpc, but not leinster (which is a DEC ALPHA machine). So, after logging into one of the SUN's in BSB424, you can use all the programs that are on the computer you are sitting in front of.

You can also run gv or g98 from one of the SUN fishes (client names) in BSB 133 if you first ssh

to erin or hpc. Clam is their server and they are connected to their own hard drive.

To use the GausView program on a SUN you must tell the SUN to allow outside

computers (erin, scivis, etc.) to display things on the SUN computer. To do this you type in one of the SUN windows:

xhost +

This command is valid throughout the session until you logout. After typing the xhost command you can then use the gv command in the erin window. (You cancreate the erin window before or after the xhost command, the gv command typed after the xhost command.)

Message #2: (After the first class)

The .cshrc file is used every time you open a new xterm window. It stores many useful commands that would have to be typed in the beginning if there weren't a .cshrc file. One of the commands that can be put in .cshrc is the alias command. This is to abreviate long commands, For example,

alias ll "ls -la"
(alias abbreviation "full command")

makes the new command ll which when typed does the same thing as ls with the la options. Another one is

alias tlh "ssh hpc"

Instead of typing <ssh hpc> while you are on clam, another fishy, an Irish county, or hpc0x you can

just type tls when you want to run big jobs on hpc.

<ssh hpc> might not seem like a long command type in but a command that you will be using over and over in a session is:

alias grsfd     "grep 'scf do' \!* ; grep -i 'mum f' \!*; grep -i 'mum disp' \!*"

I will give you more usefil aliases in class.

Message #3 (For Topic 5)

We have four more computers for our use, leinster(pronounced lenster), munster, ulster, and connacht(pronounced conn-ahkt). They are the names of the four ancient kingdoms of Ireland.