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Damn Small Linux can be an excellent tool for learning Linux commands and running the Linux operating system. But what if you are not interested in becoming a computer nerd; can this software still be useful to regular people? The answer is a resounding yes; you can make use of this tiny operating system whether or not you want to learn the sometimes gruesome details of operating systems. This article presents several free games that are immediately available once you have downloaded and installed Damn Small Linux.
To access these games either click on the DSL button in the lower-left hand corner or on the Apps icon toward the top of the screen. Then open the Games: there are eleven; Canfield, Freecell, Golf, Mastermind, Minesweeper, Pegged, Slide_Puzzle, Solitaire, Taipei, Thornq, and Xtris and Taiedit which is not a game, but a game editor. We will look at the games in order starting with Slide_Puzzle. As with any gaming systems, you must be careful not to get addicted.
Do you remember a hand-held non-electronic game that contained fifteen movable tiles and sixteen squares? By moving the tiles correctly you could reconstitute a series of numbers. Slide_puzzle is similar but even more challenging. First you load an image, a graphics file such as a jpg file. I didn’t have one readily available so I opened Firefox went to google images and downloaded into the /home/dsl directory the first crayfish image that Google offered me. Then I loaded it into the game which chopped it into little pieces to be reassembled. Left-click on a tile to slide it into the adjacent empty space. Right-click to see the original image. If you are really good you won’t have to take a peek at the original image. It helps if you selected an image that’s easy to reconstitute. I don’t recommend crayfish.
Solitaire is the good-old Klondike solitaire card game. While testing it for this article I won twice in a row and even came close the third time. This is the solitaire that I fondly remember as a kid. Watch out, it’s moderately addictive.
Taipei is a very addictive game in which you try to remove pairs of corresponding tiles. Of course whenever one tile is covered by another tile you must first remove the covering tile. To find out if a tile may be removed right-click on it. If it changes colors it may be removed by clicking on its available partner. The partner tile is usually a copy (9 and 9, Heart and Heart) but any of the direction tiles may be paired with any other direction tile, and any color tile may be paired with any color tile.) The numbers in the lower left hand corner of the screen indicate how many tiles remain and how many tiles are presently removable. In one game I started with 144 and 12. By judiciously removing two tiles I went to 142 and 15. I lost that game, like I lose most of the time. If the rules sound a bit complicated, they are. But you can learn by playing. And you can always press the Backspace key to undo your latest tile removal. The last time I played I was blocked, pressed the Backspace key, and went on to win. Some would say beginner’s luck. The instructions claim that every game can be won. I don’t believe it.
Taiedit lets you modify the game of Taipei. Good luck, this application looks moderately sophisticated.
Thornq is yet another solitaire card game. For more information about this game access their website at www.delorie.com/store/ace/docs/thornq.html .
You may not believe me, but I won this game without knowing how to play it. Beginner’s luck. The point is that Damn Small Linux offers a wide variety of solitaire card games. The final game offered with the system is xtris, a version of Tetris, a game in which you arrange falling blocks. This version offers a few controls including the possibility of playing several games at once. One at a time is more than enough for me.

Linux is an alternative operating system for computers. It’s one of the most well-known example for free softwares and open source codes. It can be freely modified, used, and redistributed by anyone.

In the interest of the system’s security the most important and the available files are separated. Linux can be used by more users. This would make the computer more vulnerable but it doesn’t. The users don’t have access to the root’s applications so we can’t modify them accidentally. The viruses can’t access to the system settings because the configure files are in a /etc directory and all this together gives the stability of the Linux.

Security-Enhanced Linux (SELinux) is an extra security service. We can define in one configuration that who has access to which applications and server and network procedures. This makes our network more protected.

SELinux implements security policies with the use of Linux Security Modules. LSM is a framework that lets Linux kernel to support security models. It has a lot of features for example the interfaces are well-defined, the policy is very flexible and it support for policy changes. The controls over the file systems, directories, files, messages and network interfaces are strong.

SELinux has become available for simple users with in a package with Red Hat Enterprise Linux version 4 and all future releases as well. It can be installed not only with Red Hat but with Fedora, Hardened Gentoo and Yellow Dog as well.

www.infosecuritylab.com

Just to set the record straight, we must tell you that Microsoft Windows comes with plenty of free applications. The most widely used freebie is Internet Explorer. To find most of the others go to Start, All Programs, Accessories, and start clicking. Why don’t you take a look right now? Outside of Internet Explorer how many free Windows applications do you actually use? When you feel like word processing do you fire up Notepad, Word Pad, or Microsoft Word? Guess which two of these word processors are free.

Equipping an office with the standard Windows applications is an expensive activity. Some Microsoft applications make you purchase the software itself and then pay additional licensing fees when you connect your Microsoft client computer to a Microsoft server computer.

Damn Small Linux applications are free. Some of them are included with the initial download while others have to be downloaded and installed subsequently. There are several reasons for this seemingly intricate procedure. Not everybody wants to use the same applications. Furthermore, the very strict selection of the applications in its base package helps the Damn Small Linux distribution to respect the hard to believe 50 Megabyte limit. Once you have installed Damn Small Linux you can download Open Source (free) versions of Office and run them under Linux. Please note that you can download and run these programs under Microsoft Windows as well.

All work and no play makes Jack a dull boy. Well Jack doesn’t have to worry if he’s running Damn Small Linux. It comes with lots of free games. Somehow we have the impresssion that you will not need any tutorials to get the games running.

Some Linux applications are not only free but are actually superior when compared to the corresponding Windows applications. For example, have you ever heard of an e-mail client called Sylpheed? This application is part of the basic Damn Small Linux distribution. It has several advantages over those extremely popular (perhaps we should say unpopular) Microsoft e-mail offerings, Outlook and Outlook Express. Sylpheed handles spam much better than do its Windows counterparts. And Sypheed allows you to process threads of e-mail messages. For example, you correspond with several people about wholesale wine purchases. Sypheed makes it easy to process those messages while ignoring unrelated ones.

Since we’re talking about email, what about it’s cousin the Internet? That will be the subject of our next article in this series.

Linux and Windows share many characteristics. For example, most people have little interest in knowing how they work. These operating systems make the computer available for the applications that people want to apply; such as running an Internet server, browsing the Internet, creating and accessing data bases, writing programs, playing music, or, or, or. These tasks are coordinated by the operating system and require specialized programs that drive hardware efficiently and correctly. We’ll talk about Linux’s closely integrated “friends” and compare them to the similar but oh so different Microsoft offerings.

The Linux group is called LAMP, an acronym standing for Linux, Apache, MySql, and PHP. There is no similar Microsoft acronym for their set of interacting products. Could that be a symptom of their relatively low level of integration? In contrast Linux is closely integrated with the other LAMP components. In a sense these companions grew up together. Improvements to one component are easily transmitted to the others. These programs are all Open Source meaning that the actual code for all components is readily available. When a problem such as a security breach occurs (don’t let anybody tell you there are no security breaches in Linux and friends) people work on the problem and may post corrections rapidly. Now let’s look at the other LAMP components.

Apache is a highly regarded web server. It has been the most popular web server on the Internet since April, 1996. Believe me, if Microsoft with its virtually unlimited resources cannot dislodge Apache from the top of the pack this software must be doing a lot of things right. Of the four LAMP components Apache is the one that non-specialists are least likely to try to learn. But if you want to play with it, guess how much it costs. You can download a version which will run under Windows but it is unlikely to contain the full functionality. At the time of this writing the Windows version of Apache has some problems concerning its cryptographic functions. Apache is undergoing constant development; its new features, security enhancements, and bug fixes will be available first on the Open Source (LAMP) version. And then filter down to the Windows version.

MySQL is the most popular Open Source Database Management System. The MySQL Community Server is free. The more powerful MySQL Enterprise Server starts at $595 per server per year, a very reasonable price for a commercial product. Microsoft’s competitive database management system is Microsoft SQL Server. Licensing of this software is fairly complicated and believe me, costs a lot, lot more than does MySQL Enterprise Server. Microsoft often makes you pay for purchasing the server and client software and then pay annual server licenses and client licenses for system access.

MySQL runs on a wide range of hardware in conjunction with various operating systems. You can guess from its name that Microsoft SQL Server runs only under Windows. Both of these database management products are constantly upgraded and many technical features that once were available only on SQL Server now run on MySQL. In the past SQL Server clearly surpassed MySQL for enterprise-level systems, while itself often losing out to Oracle or other database management systems. Today’s reality is more complicated and MySQL Enterprise Server manages many huge database systems.

Talking about size, we didn’t finish discussing LAMP components in this article. PHP is the subject of the next one in this series.

And here is our technology history lesson for today. In spite of what you may think, Bill Gates and Microsoft did not invent the Internet. In fact, these visionaries jumped aboard the information highway fairly late after vainly trying to counterpose their own MSN to the Internet.

In contrast Unix computers have been accessing the Internet and what’s more running the Internet for decades. Unix and the Internet have had plenty of time to evolve together. Of course you can access the Internet from Windows with Internet Explorer, Firefox, and numerous other browsers. Many sites do use Windows-based Internet servers. Whether you are a casual Internet user or an Internet Service Provider you probably want to know the concrete differences for you and your associates to help choosing between Linux and Windows for meeting your Internet needs. (Actually Internet Service Providers tend to know the differences and have made their choice, which is usually Linux. In the interest of fairness I must tell you that their choice is definitely not Damn Small Linux ‘ it’s just too small.) Let’s examine some important differences between Linux and Windows in respect to the Internet.

Linux browsers are much less likely to stall than their Windows competitors. This increased stability reduces those annoying Internet browser restarts and even more annoying operating system restarts. This latter advantage is particularly important for Internet Service Providers but is also important for individual Internet users.

The Linux Internet experience is much less likely to be interrupted by Adware, in which intruders foist their junk on unwilling victims. As far as I’m concerned Adware is theft of my time and energy. In spite of their claims I have a sneaking suspicion that I’m not the 10 millionth visitor to their site and even if I were there is no way that I won any free vacation to Las Vegas or Never-Never Land. Linux systems clearly surpass Windows when it comes to blocking these criminals and letting me do my Internet work or have my Internet fun.

I don’t want anybody snooping around my stuff, whether on the computer or not. Spyware is often a major problem with Internet browsers that run on Windows computers. Linux systems are more resistant to Spyware than their Windows competitors. But in the interest of fairness I want to refute those silly claims that Linux computers are completely resistant to Adware, Spyware, hacking, viruses and the like. Whatever some people can build, others can tear down or worm their way in.

This brings up our next subject, computer viruses. Do you think you can guess which operating system is better equipped to combat this major problem?

Unlike Windows, Linux users must have an account. This account is accorded permissions such as reading and writing files and executing programs. Accounts are combined into groups to simplify their management. Users who are members of a given group may be assigned additional permissions that smooth the process of accessing common files. Let’s take a closer look at how Linux handles these users. A future article examines permissions and groups.

Linux provides two categories of users, ordinary users essentially restricted to working with files of their own creation, and the superuser, or root, who administers the system and is allowed to do almost anything. The real situation is of course somewhat more complex. For example, ordinary users may be accorded restricted access to additional files deemed to be of interest to everyone. The superuser can assign some privileges to deputies reducing an otherwise crushing workload.

The root user is the only one authorized to run the adduser or the more complicated useradd command. If you have downloaded Damn Small Linux you can test these commands on your Windows computer. In response to the adduser command Linux requests the user name, the password, and then a few optional fields that may be skipped. An organization with many users has or should have a policy for composing user names.

The password is a key element in protecting the computer’s security. We could easily write an article discussing the password and password selection. Remember that Linux distinguishes between lower-case and upper-case letters. If you’re new to computing you may try working with easily remembered passwords at first. But protecting your account and account information depends on your unguessable passwords.

When Linux creates your account it also creates a directory whose name is easy to remember. If your account name is lucy then your working directory is /home/lucy . I’m leaving it up to you to find out the location of lucy’s working directory for Windows systems.

Damn Small Linux shares an interesting feature with many other Linux systems. The system administrator can provide new users with copies of some directories and folders by placing them in the /etc/skel directory before launching the adduser command.

How is the system administrator supposed to handle creating dozens, hundreds, or even thousands of new users, for example at the beginning of the semester? He or she won’t have the time to undertake this backbreaking task. And there is no way that the root password should be revealed to the employee who is assigned this task. The answer is simple: write a program to create these new accounts. This program can even spiff up the account creation interface and perhaps grab some necessary information from sources such as the student registration file.

Of course we don’t want to create users without the possibility of removing them. The live process is fairly complicated and includes removing the user’s password from the /etc/passwd directory, removing all files from the user directory, and other activities such as making backups of essential information. The next article discusses the related concepts of permissions and groups.

A shell is the command interpreter program that serves as an interface between some users and the operating system itself. We say some users because most users rely on the graphical user interface. The Windows shell is the DOS command line interface accessed by clicking on Run and then entering the cmd command. The Windows graphical user interface is Explorer. This article describes the Damn Small Linux shell interface and several utilities, useful programs that may be launched from the shell. A subsequent article will describe the corresponding graphical user interface.
Why would anyone want to bother with a shell when the prettier, easier-to-learn and easier-to-use graphical interface is available? The answer is: It depends who you are and what you want to do. For system administrators or their associates it’s often much less cumbersome to use the shell rather than the graphical user interface. While Damn Small Linux commands may be quite arcane, they can be very powerful. And efficient. The Linux tools for performing administrative and other technical tasks admittedly take time to learn and master. But it does the job and does it well. In all fairness, many Windows systems administrators often apply command-line utilities. But they don’t have a powerful shell to help them do their work.
Historically Unix used the Bourne shell, the C shell based on the C programming language, and the Korn shell. Linux’s most widely used shell is Bash, also spelled BASH, the (Bourne-Again Shell). Damn Small Linux offers many shells but most people go with Bash both to communicate interactively with the operating system and to write programs known as shell scripts. If you program in Linux no matter which programming language you use you should learn some Bash specifics.
Utilities enable you to handle some very sophisticated processing. You can think of them as commands or as prewritten programs. Unix-Linux people often send the output of one command or utility to another command or utility for further processing. For example, the ps command displays active processes. It tends to generate voluminous output, especially in a busy system. Let’s say that you are interested only in the processes associated with a given terminal. You send (the technical term is pipe, expressed by the | character) the output of the ps command to the grep utility which looks for patterns within the input. You code a single line, multipart command to obtain the list of processes associated with that particular terminal. Unix and Linux are well known for elegant solutions. In contrast the Windows solution to this information need is much more clumsy.
The grep utility has many other uses including validating e-mail addresses. Let’s say that your web site asks potential subscribers to furnish their e-mail accounts when signing up for a newsletter. A sophisticated but relatively short statement coded in grep could validate e-mail accounts.
Other Damn Small Linux text processing utilities include the related egrep and fgrep commands, mawk a pattern scanning and text processing language, sed an editor that handles large files, and diff a utility that compares files. DSL provides utilities that compress and archive files, and a wide range of other utilities. If you need them, these Linux utilities can be quite useful and time-saving.
Our next subject is Linux programming support.

Can you remember the 1992 Janet Jackson song entitled The Best Things In Life Are Free? You might even remember the 1956 Hollywood movie of the same name. In any case do not guarantee that you will find Damn Small Linux and our associated tutorials to be among the best things in your life. On the other hand we do guarantee that they are both completely free. Well, wait a minute. They are both free, but…

You may have to shell out some of your hard-earned cash to learn Linux. This is particularly true if you are downloading the software and running the tutorials on your home computer. Yes, you will have to pay for an Internet connection at least for the time spent downloading the files. By today’s bloated standards Damn Small Linux is really small; it weighs in at a mere 50 Megabytes. Downloading this software distribution is really quick, especially if you have a high-speed connection. And yet as we all know, sometime during the following month your Internet Service Provider will want money.

After downloading Damn Small Linux you won’t need the Internet to run it. But you may want to activate one or both of the Internet browsers that are part of the Damn Small Linux distribution. And you may want to download additional applications; there are lots of them. Because Damn Small Linux is so small you should still have scads of disk space available.

Your Damn Small Linux costs don’t end with the Internet. I would be surprised to learn that the electricity powering your computer is free. Surely the longer your days and nights spent in front of the computer the higher your light and heat bill. Furthermore, the more time you spend on Linux the more money you may end up spending on snacks, new eyeglasses, and taxis when you miss the bus to work because you just couldn’t tear yourself away from the computer in time. I think you get my drift. But we repeat. Damn Small Linux, this website, and many of the references on the web are free. Should you outgrow Damn Small Linux the larger versions of Linux are free, or at least quite inexpensive when compared to ostensibly similar versions of Microsoft Windows.

Most people don’t run operating systems in and of themselves but rather for the applications they enable. Reason number two: Damn Small Linux provides lots of free applications as discussed in our next article.

Let’s start by mentioning a few facts that can be very disconcerting to die-hard Linux and Unix fans. Serious computer viruses appeared first in Unix systems. And arguably the worst computer virus attack in history occurred on Unix systems about twenty years ago. The good news is that the lessons learned from this attack were integrated into the constantly evolving Unix and Linux systems. Of course, to some extent they have been integrated into protecting Windows systems, and that’s also good news.

One reason that Linux surpasses Windows for virus resistance is that Linux is open source. When an attack occurs hundreds or perhaps thousands of techies start working on solutions and post them to the Internet. You won’t have to wait for an anti-virus company to come up with something.

What other factors make Linux systems more virus resistant? For a virus to take effect it must be part of a running program. Simply opening an attachment in the Microsoft Windows environment does the trick. The last time (pun intended) I opened an electronic greeting card on my Windows computer I was rewarded with a nasty virus. It took quite some time to remove it even with the aid of technical support. Linux systems won’t launch the virus unless the user reads the email, saves the attachment, modifies the appropriate permission assigning execution permission to the attachment, and then explicitly executes the attachment. Unless all these steps happen the virus remains in quarantine. While an educated Linux user could carry out all these steps unleashing the virus this unhappy state of events doesn’t occur often in properly organized systems.

Another limits virus impact in the Linux world. Ordinary Linux users don’t have permission to do a lot. Even if they unleashed a virus it usually wouldn’t go very far. Getting beyond the individual computer requires administrative power – the kind held by Root Users in Linux and Administrators in Windows. Regular users of Linux are usually not accorded root permission. In contrast, a newly installed Windows system automatically creates the first user as an Administrator. In our mind this is asking for trouble.

Just think – a regular Windows user has permission to install files that can run amok and destroy lots of good things. It seems that in Windows the operating system, the applications, and the data are inextricably intertwined. As if they were asking for trouble.

I have read that bananas are in danger. It looks like biodiversity is a thing of the past in banana-land or at least in the commercial banana world. So there is some chance that one powerful banana virus will make banana splits a thing of the past. The very diversity of Linux systems offers some protection. And it’s a LAMP onto the world as discussed in the next two articles.

Damn Small Linux can be an ideal platform for supporting a wide range of programming languages. You can even program directly from the command line via a programming shell such as Bash. Major programming languages used in this environment include C, C++, and Java. If you are developing for the Internet you may want to use PHP, a web programming language and MySQL, a language for database system development. All these programming languages are also available in the Windows environment. So the question arises, why would you want to program under Linux rather than under Windows?
Many web developers and Internet service providers feel that Linux provides a more stable web site environment than does Windows. The most widely used web server, Apache, is available under both these operating systems but its new features, security enhancements, and bug fixes always are made available first on the Open Source (LAMP) version. And then they filter down to the Windows version. At the time of this writing the Windows version of Apache has problems with its cryptographic functions.
While programming languages are essentially the same across these two operating systems, their libraries are quite different. Basically, when you write complicated programs you want to make use of as much prewritten software as possible to reduce your programming and debugging effort. One example is handling the graphical user interface. As programmers often say, why reinvent the wheel? Linux provides a wider choice of libraries and graphical user interface toolkits.
When you program in Linux it is often fairly easy to port your programs to the Windows environment. Unfortunately, the inverse is rarely true. Of course as Linux systems become more popular, you will find more and more Windows-based programming systems that enable you to convert your programs to run under Linux. To do so makes clear economic sense.
Program conversion tools may be fairly difficult to develop. For example, executing programs must access the actual computer hardware. As you may imagine Linux and Windows programs access hardware quite differently. The modules that manage hardware access are called drivers. Linux drivers tend to be of higher quality than Windows drivers.
These two operating systems differ substantially in the way they manage programs during their execution. In other articles we discussed Linux’s increased security compared to Windows. We conclude this article by repeating a point that we have often made; you can run Damn Small Linux and its associated applications on very reduced hardware. You can do Linux, PHP, and MySQL development on old computers, ones that may have seemed ready for the garbage heap. In contrast many Windows competitors such as SQL Server Developer Edition require substantially more powerful computers, the kind of computers that people purchase for one or a few thousand dollars. When your programs will be used by dozens of people simultaneously, you will need powerful hardware. Don’t forget the operating system; can you guess which one we recommend? Our next subject is the graphical user interface.

Damn Small Linux is an excellent tool for learning Linux commands and running the Linux operating system. But what if you don’t plan to be a computer nerd; can this software still be useful? The answer is a definite yes; you can make use of this tiny operating system whether or not you want to learn the sometimes gruesome details of operating systems. This article introduces the text editors that come with your free Damn Small Linux that runs on even obsolete Windows computers. You can use these applications to compose simple text or programs of any level of complexity.
Once you have downloaded and installed Damn Small Linux there are several equivalent ways of launching its text editors. You can click on the DSL button in the lower-left hand corner or on the Apps icon toward the top of the screen. Then open the Editors: there are four, Beaver, Nano, Notepad, and vi (actually vim). We will look at these editors in order plus an additional one.
Beaver is my choice for creating and editing the text files used in my Damn Small Linux tutorials. The name Beaver stands for Beaver is an Early AdVanced EditoR which is the kind of joke that many Linux and Unix people find funny. This editor is particularly useful for programming and web page editing. Beaver’s special features include color coding and the ability to convert text to Upper Case, Lower Case or to capitalize the first letter of every word. You can convert text among the following formats: Unix, DOS, and Mac. Programmers will be glad to know that Beaver formats code for the following programming languages: C/C++, HTML, Perl, JavaScript, PHP, and Bash. Unfortunately there is no Help function.
The nano program is especially used for email messages. It stems from the widely used Pico email program that is not available for some versions of Linux. I have not worked with nano but am told that many Linux and Unix people like it.
What the Damn Small Linux people call Notepad is actually another text processor that is similar to the DOS/Windows Notepad. I haven’t used it because Beaver is more powerful, and just about as easy to use.
The final application in this group is VIM, vi IMproved. The original vi was a very-widely used text editor for Unix and Linux systems. Today almost all Unix and Linux people work with other, more sophisticated text editors. When I teach Linux on systems other than Damn Small Linux I teach a reduced version of vi. This editor is cumbersome, but you make like the improved version. Damn Small Linux offers you a choice.
The Office folder includes Ted, a word processor which is compatible with Microsoft Word. Ted saves documents in RTF (rich text format) that can be read by Microsoft Word and other word processors including Open Office. Ted and Beaver belong to different worlds; you can’t take documents back and forth between these two applications.

Linux people like to claim that directories are really just another type of file. This statement can be misleading. We saw in a previous article that you create a file using a file editor. We will see later in this article how to create a directory.

So just what is a Linux directory? A directory is a collection that may include one or more directories, one or more files, or in fact be empty. You may think of a directory as a computerized file folder or loose-leaf notebook that contains dividers (themselves directories) and pages (files.) Just like a notebook page may not contain a divider, a Linux file may not contain a directory.

Up to now our comments about Linux directories hold for Windows directories as well. Now let’s take a look at some differences between these two systems. First come the naming conventions. Linux always distinguishes between lower-case and upper-case characters in directory names. Microsoft Windows does not. For example, Linux treats pay12june and Pay12june are as two different directories, as different as the directories pay12june and heighho. These directory names were used as file names in the previous article. While Linux does have some reserved directory and file names, in general one cannot tell by the name whether it is a file name or a directory name. So be careful. Linux helps you out here ‘ the ls command that lists the contents of a given directory usually displays files and directories in different colors.

Directories are hierarchical. They resemble a tree or a family tree. But unlike a tree (or Microsoft Windows) Linux has only one root. The root, designated as / lies at the top, rather than at the bottom, of the hierarchy. Right underneath the root directory you will find several subdirectories. For example, the /home directory is a child of / the root directory. The number and names of the first-level subdirectories vary from one version of Linux to another. For example, some Linux distributions include a /root directory while others do not. The /root directory (or subdirectory, both terms are used) is a child of /, the actual root directory.

The /home directory is an important directory. It is divided into subdirectories, one for each user. We like to work with Damn Small Linux, a free version of Linux that runs on the Windows desktop and requires only 50 Megabytes of disk space. Damn Small Linux automatically creates a user called dsl whose home directory is /home/dsl ; a working area essentially reserved for this user. All Linux versions subdivide the /home directory into user subdirectories according to this simple naming convention.

Linux provides several commands to process directories. For example, the mkdir command creates a directory. The rmdir command removes a directory, but in the simplest case only when it is empty. The cd command changes the working directory, the directory in which you are positioned. The pwd (print working directory) command displays (not prints) the working directory. Beginners should run this command often to reduce errors. For example, if you, the dsl user, think that you are positioned in the /home/dsl directory but in fact are positioned in the / directory you won’t be able save your files with a simple command. Why? Because you lack the requisite permission, the subject of our next article.