This page will serve as a very cursory overview of the key points to using a Unix-like operating system in the course of our daily work here in the lab. Entire books have been written on this very subject so only the most crucial points will be hit upon and the tone will be towards the absolute novice user. If you have never used Unix before, using the information on this page should at least allow you to look busy while sitting at a terminal.

A very common operating system (OS) installed on many of the lab's computers is GNU/Linux, commonly just referred to as "Linux". Other, older systems have a "true" Unix installed called OSF1 (Tru64) Unix.

Once logged into a Unix or Linux machine, you will be presented with a prompt likely similar to one of the following:

• js123_lnx6166>
• [js123@lnx6166 ~]$

That prompt indicates that the command shell is now waiting for you to tell it something to do. The command shell is a small program that runs automatically and its purpose is to interpret your commands and see to it that they are executed in the way you wish. There are two main families of shells installed on the lab's computer systems. Minor wars have probably been started over opinions on which is supposedly superior and this tends to boil down to personal taste. The two types of shell are

• The Bourne shell and it's derivatives -- sh, bash
• The C shell and it's derivatives -- csh, tcsh

The table below summarizes the most commonly needed commands in a Unix or Linux environment in the course of daily activities.

Command	Description
man <command>	Print the MANual page for a given command. Insanely useful.
info <command>	Similar to man, sometimes gives more in-depth information.
pwd	Print your current working directory
cd <dir>	Change your current working directory to some other directory
ls	List of all files in your CWD
ssh	The secure shell program for obtaining shell access on another machine

-- MattRendina - 19 Sep 2007