Aerospace Software Ltd.

The Linux Experience

For a die hard MS Windows user, working on a Linux computer is a little disconcerting. Most things work as expected, but a few things are strange. This guide attempts to explain some of the strangeness.

A typical Linux system comes with an enormous amount of software pre-installed. A Mandrake or Suse distribution has several CDROMs loaded with applications for hobbyists and professionals alike.

Your first problem therefore, is to figure out which of these 50,000 odd programs are meant for you. Years later, you will still discover useful programs that you wish you knew about long ago!

Logging In

You should be used to logging in with a username and password, but you should now get a choice of desktop environments. Select KDE, since it is the most MS Windows-ish desktop system.

If you want something a little different, select Gnome and if you want something simple and blazingly fast, select Ice. There are many desktop environments for Linux, but some are so weird, that it can be very difficult to figure out how to use them, so I suggest using KDE for starters.

The Desktop

When you sit down in front of a Mandrake Linux terminal, it should all look quite familiar. Both the KDE and Gnome desktops follow the Xerox PARC model and look very much the same as the MS Windows and Apple Macintosh desktops. It is somewhat like moving from an American to a European car - the differences are there, but they are subtle and present little difficulty.

Pretty soon, you'll find the Menu button and you'll have no trouble finding Office Applications or whatever you are looking for. Playing a music CD or writing a document will be straight forward.

Only once you have written a document and you want to save it, will you begin to notice some peculiarities.

File System

The MS Windows file system assigns drive letters to physical media and network shares. Your local hard disk is typically called C: and the CDROM is D:, while networked shares may be letters all the way up to Z.

On a Linux system, you don't have drive letters. The whole file system is described with English directory names in a single tree of subdirectories. There is some method in the madness though.

The base of the tree is called / (slash), so first of all, you have to learn not to type backslashes as in MS Windows file names. The slash key is under the question mark. Bear in mind that it is not Linux that is different - Unix was first, it is Windows that is different... ;-)

Every user has a private directory under /home. If your user name is Bob, then you will have a home directory called /home/bob and all your private data is in there.

Your CDROM drive is under /mnt/cdrom and the floppy drive /mnt/floppy. Usually, you need not be concerned with that, since you have icons on the desktop that open those devices, allowing you to drag and drop files to and from other directories.

There are many other directories, such as /root, /etc, /usr and /var - those are all good places to stay out of for now. Consider those directories to be the equivalent of the c:\windows directory - to understand those areas, you have to read a few Linux books.

If you stray into the system directories, it is very unlikely that you will be able to do any damage, since ordinary users cannot modify those areas, even if they try. You have to be a Super User to do damage.

The division of power between ordinary and super users is one of the corner stones of Linux security.

Managing Your Data

Say you wrote a little test document and you want to save it somewhere. Your word processor will by default try to save the file in a place called Documents. This directory is actually /home/bob/Documents.

Note the case. Linux is case sensitive, documents is not the same as Documents...

In general, it is best to keep all names in lower case and not to use spaces in filenames. Eventually, you are bound to find uppercase letters and spaces in filenames to cause you a weird headache - best avoided.

When you download a file from the internet using a browser, it will likely try to put it on the desktop so you can easily find it again. Your desktop is /home/bob/Desktop.

On the desktop, you will notice an icon called Home. If you double click it, it will open your home directory /home/bob and list all the files and directories in it. You can use this file browser to create new directories to store stuff in, or move things around between existing directories.

When you double click a file, Konqueror will try to run the relevant application to handle that file.

The Konqueror file browser is also a powerful web browser. If you type a URL in the directory box, it will open it up, eg. www.cnn.com will zoom off to the well known news site.

You will soon find that you use Konqueror for most things, you can even browse a MS Windows network with it.

E-mail Viruses

A nice surprise awaits when you receive rubbish e-mail. Linux is immune to Windows viruses and there aren't any Linux viruses, so you can open and click any e-mail with wild abandon if you are so inclined.

Your system is perfectly safe despite not having a virus scanner at all. The only reason for filtering out trash from your mail, is to reduce the clutter in your inbox.

The reason why there are no Linux viruses is that unlike in MS Windows, a program needs to have an execution flag set before it will run and only a Super User can set that flag.

To run an e-mail attachment, you have to first save it somewhere, then become a super user, change the execution flag and then launch the program. If you don't know how to do that, then you can't run the program and if you do understand how, you are even less likely to do so.

Therefore, if someone sends you stuff and you click it and it opens up, fine, then you can read it and if it doesn't open up, then it is just as well since it is probably a MS Windows virus.

The important thing is that you can relax about your e-mail. It can't do any damage.

Managing Your Desktop

The KDE desktop is extremely configurable. Most simple things can be set from a right click on the desktop, but there are also configuration utilities in the menu system.

The configuration utilities are best avoided, until you have read a few Linux books. It is possible to screw up the KDE desktop and make it rather hard or impossible to use.

The KDE configuration is stored in your home directory in a sub directory called .kde (dot KDE). In Linux, any filename starting with a dot, is hidden, though you can set Konqueror to show hidden files in its View menu.

In general, it is best to stay out of the dot directories and don't delete any files or directories starting with a dot, since those things tend to be important.

Printing

The common Linux printing system is called CUPS (Common Unix Print System).

An important point to remember is that CUPS effectively turns any printer into a PostScript printer.

Therefore, if you want to print to a printer attached to another Linux box, then you can tell your computer that the foreign printer is an Apple Laser Writer II and the system will print perfectly, irrespective of what brand or model it really is!

Occationally, something may go wrong in the communication with a printer and you may get a runaway printing process, where the printer keeps on spitting out page after page of meaningless gobbledygook.

It is very important that you know how to stop this. First of all, turn the printer off, or yank the paper cassette out to stop the waste.

Now launch the Konqueror web browser and type the URL:

http://localhost:631

That will launch the CUPS configuration utility.

In order to change anything, in this case, delete a print job, you need to be a Super User, so you need to dig out your Super User password.

Click on 'Do Administration Tasks', enter username 'root' and the 'password'. Now you can click 'Manage Jobs' and delete the active job.

After that, you can go and start the printer again.

Cut and Paste

There are various ways to cut and paste text in Linux.

You can use the MS Windows method: Highlight text, press Ctrl-C to copy it to a buffer, go to the new spot and press Ctrl-V to paste it.

You can also use the X-Windowing method: Highlight text, go to the new spot and press the middle mouse button to paste it.

Sometimes, the X method is problematic if the highlighting goes away while moving to the new spot. You have to try it and see for yourself and get used to it.

Restart X

Linux systems seldom need to be restarted. However, if you decided to try the Fluxbox desktop system and you cannot get going and cannot figure out how to get out of it either, then is useful to know how to restart the X-Windowing System.

The magic key combination to restart X is Ctrl-Alt-Backspace. It will instantly blow the desktop away and present you with a fresh login screen.

Whatever you were working on will be lost of course...

Restart Networking

If you are experiencing networking trouble, say with a wireless access device, then it may be useful to know how to restart networking, without restarting the whole system.

Open a terminal eg. Konsole and type the following:

$ su -
yoursuperuserpassword
# /etc/rc.d/init.d/network restart

Installing New Software

Eventually, you'll need to install new software. This is best accomplished by using the rpmdrake utility and rpmdrake is best launched from the drakconf utility.

Click Menu, System, Configuration, Configure your Computer, enter the super user password, select Software Management to get to the utilities to add or remove programs.

You'll need to experiment a bit, but once you get to this point, you are an advanced user and not a novice anymore, so congratulations are in order!