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About Basic UNIX Commands

Firstly you need to log in.

Once you have logged in for the first time, your first priority should be to reset your password from the one you gave when you joined to something else. To select a password, you should consider the following guide lines:

Use at least 6 different letters/numbers/symbols
Use a mixture of lower and uppercase
Use a mixture of numbers and letters and symbols
Don't use names of family members / boyfriends / girlfriends etc.
Don't use words which appear in the dictionary
Do consider using acronyms (with mixed case) to generate what would appear to be a random mix of letters, numbers and symbols to anyone who didn't know the acronym.

In order to change your password, type the command passwd. You will be prompted for your old password and then you have to enter the new password twice. Once you have done this there is no way for any of the Computer Society System Admin to find out what your password is. If you forget your password, it must be reset by the Admin to a new one.

The Command Line
When you login, you will be faced with a variety of messages which end up with the display of a prompt. At this point you can type in commands; pressing return results in the commands being executed. To start with try out some of the commands listed below. They all return immediatly to the command line after they have executed resulting in the display of another prompt at which you can enter another command.

Here is a list of simple commands with brief descriptions:

ls List files in the current directory
ps List all the process you are running
who List who is on the system and where they are
w List who is on the system and what they are doing

Most commands are very short; they are often used with command line arugments. If you type:

ls -la

Then you will get a long listing of all your files. The "-la" part of the command is referred to as it's command line arguments. You could also try:

ps -aux

As this will produce a list of all the processes (programs) being run on the computer which will be much longer than the list the command produced earlier. Don't worry if you did not understand the output produced by this program, it will be explained later. If the text scrolled off the top of your screen, then try typing:

ps -aux | more

This time you will see only a single screenful of information. Press the space bar to see the next screen, press return to see the next line; pressing b will make the text scroll back one page. When you have finished viewing the document, type q if the prompt has not been redisplayed.

The Online Manual
Another useful command is the man command. If you type man followed by another command, then the instructions for that command is displayed. The man command uses the more program that you used earlier and so you use the same keys to control this program. Try the following:

man man

man who

The output from the manual program often seems daunting to the begginner, but if you learn how to interpret it, it is very useful.

Finally
Try some other commands, such as those below:

finger username - Find out about others on the system
talk username - Talk to another user
write username - Write to a users screen
cp file1 file2 - Copy a file
mv file1 file2 - Move a file
mkdir name - Make a directory
rmdir name - Remove a directory
cd name - Change directory
cat name - View a text file (use cat file | more if the file will not fit on the screen)
chmod perms name - Change file permissions
chsh - Change your login shell
chfn - Change your real name and contact information on the system