Essentials

To follow along with the examples shown here using the virtual machines is it safer to use an account other than the administration account (root). By pressing the button below a new account is created called "demo", password is also "demo". Log in using this account and you cannot do any damage. If you mess the account up and want to start again, just press the button again.

Once created, you can log into this account using telnet or ssh, logging into the hostname linuxzoo.net. Remember the username is demo and the password is demo. And remember, you cannot break anything using this account! The account begins with an empty directory, so dont be shocked that "ls" shows nothing...

MAKE SURE YOU USE THE USER demo. If you do this with "root" or another account, you will be marked wrong. If you start with the wrong user, make sure you delete any files you created wrongly before changing to demo.

To access the system you need to start the image (select the most up to date Centos image available). You then need to log into the image remotely using a variety of methods. You should try to use telnet or ssh, plus the graphical interface VNC. You need to have either ssh installed (e.g. putty.exe) or use the JavaScript ssh. Note putty can only be used if you have a unique public IP, so if you are sharing behind a NAT you must stick with the JavaScript interfaces.

On some highly secured networks, you may not be able to use ssh, but give all of the methods a go and try to get both a command prompt "terminal" interface and VNC working.

The username is "demo" and the password is "demo".
The terminal is started within the graphical interface by clicking on the terminal icon at the bottom of the screen.

The "cd" command changes your current directory. On its own it changes it to your HOME directory, otherwise you need to specify a parameter which either is an absolute directory (such as cd /home) or a relative directory (such as cd dir1 which takes you to dir1 in your current working directory).

Type

cd
pwd

What is your current working directory? :

Make three directories in your HOME directory. Name these directories "mydir", "data", and "images".

Change your working directory into "data". Create two more directories in /home/demo/data called "dir1" and "dir2". If you create them in the wrong place delete them using "rmdir".

Change directory into dir2.

What is your current working directory? :

Change your current working directory to /home/demo. You can either "cd /home/demo" or "cd ..", as ".." means the directory above the current directory in your directory tree. Check with pwd to make sure you are in the right directory. Then try to delete the data directory using "rmdir data". What message to you get back?

Use the more powerful and dangerous command

rm -rf data

The "ls" command on its own shows you the contents of the current working directory. However it can also take a number of useful parameters.

Filenames which begin with a "." character do not usually appear when you use "ls". These are called "hidden" files, and they are used for things like application configuration and some GUI state information. They are rarely needed so this is the reason they are hidden from normal "ls".

Use the option "-a" to see the hidden files. View the hidden files in your HOME directory. The file list starts with "." (which is a directory that you can use to describe the current directory in commands) and ".." (which describes the directory above this one in the tree).

What is the first file (in alphabetical order) which appears when you use "-a" in your HOME directory, other than "." and "..". :

Use the "-l" option to see a long listing of a file. Get a long listing of "/etc/passwd" and identify its size in bytes. :

Demonstrate your understanding of relative, absolute, and the use of ".." and "/" and "." in the "cd" command by answering these questions. Try to answer them in your own head, and use the command line only if you are confused. Remember paths beginning with "/" are relative to the top level directory, whereas others are relative to the current directory. ".." takes you up a directory, and things can be seperated with "/" such as "../.." taking you up 2 directories. "." indicates the current directory, and is really only useful where you really need to specify a parameter but you mean to say the current directory. Always supply the SHORTEST solution, remember the answers are CASE SENSITIVE, and if you type spaces in an answerbox where no space should be entered then it will be marked incorrectly.

Consider these commands:

cd /usr/share/doc
cd ..
pwd

Consider these commands:

cd /usr/share
cd vim
pwd

Consider these commands:

cd /usr
cd lib
cd kernel
pwd

Consider these commands:

cd
cd ../.. 
pwd

Consider these commands:

cd
cd ../demo
pwd

Consider these commands:

cd /usr/share
cd vim/../../lib/kernel
pwd

Consider these commands:

cd /usr/share
cd /etc/sysconfig
cd ..
pwd

Consider these commands:

cd 
cd ../../usr/share/doc
pwd

Consider these commands and fill in the blank:

cd
cd ../
pwd

Consider these commands and fill in the blank:

cd /usr/share/doc
cd /
cd demo
pwd

Consider these commands and fill in the correct blank using a RELATIVE pathname. It should be the SHORTEST possible solution.

cd /usr/share/man
cd 
pwd

Consider these commands and fill in the correct blank using a RELATIVE pathname. It should be the SHORTEST possible solution.

cd /usr/share/perl
cd 
pwd

Consider these commands and fill in the correct blank using a RELATIVE pathname. It should be the SHORTEST possible solution.

cd /etc
cd 
pwd