1. Introduction

1.1 Is Linux Right for You?

You want to switch from DOS/Windows to Linux? Good idea: Linux is technically superior to DOS, Windows 95 and even Windows NT. But beware: it might not be useful for you if you are not the right type of user. In fact, DOS and Windows are mostly employed for games and office productivity, while Linux gives its best at networking, development, and scientific computing. Linux is incredibly powerful, but learning how to harness that power takes time. Thus, if mostly need commercial sw, or if you don't feel like learning new commands and concepts, you had better look elsewhere.

Work is underway to make Linux simpler to use, but don't expect to be proficient with it unless you read a lot of documentation and use it at least for a few months. Linux won't give you instant results. In spite of these warnings, I'm 100% confident that if you are the right user type you'll find in Linux your computer Nirvana, and never want to use DOS or Windows again. By the way, Linux + DOS/Win can coexist happily on the same machine.

Prerequisites for this howto: I'll assume that

• you know the basic DOS commands and concepts;
• Linux, possibly with X Window System, is properly installed on your PC;
• your shell---the equivalent of COMMAND.COM---is bash.

Unless specified, all information in this work is aimed at bad ol' DOS. There is information about Windows here and there, but bear in mind that Windows and Linux are totally different, unlike DOS that is sort of a UNIX poor relation. Please also note that this work is neither a complete primer nor a configuration guide!

1.2 It Is. Tell Me More

You installed Linux and the programs you needed on the PC. You gave yourself an account (if not, type adduser now!) and Linux is running. You've just entered your name and password, and now you are looking at the screen thinking: ``Well, now what?''

Now, don't despair. You're almost ready to do the same things you used to do with DOS/Win, and many more. If you were running DOS/Win instead of Linux, you would be doing some of the following tasks:

• running programs and creating, copying, viewing, deleting, printing, renaming files;
• CD'ing, MD'ing, RD'ing, and DIR'ring your directories;
• formatting floppies and copying files from/to them;
• tailoring the system;
• writing .BAT files and programs in your favourite language;
• the remaining 1%.

You'll be glad to know that these tasks can be accomplished under Linux in a fashion similar to DOS. Under DOS, the average user uses very few of the 100+ commands available: the same, up to a point, applies to Linux.

Introductory Concepts

The best way to learn something new is to get your feet wet. You are strongly encouraged to experiment and play with Linux: you can't damage the system that way. A few points:

• first of all, how to quit Linux safely. If you see a text mode screen, press <CTRL-ALT-DEL>, wait for the system to reboot, then switch off the PC. If you are working under X Window System, press <CTRL-ALT-BACKSPACE> first, then <CTRL-ALT-DEL>. Never switch off or reset the PC directly: this could damage the file system;
• unlike DOS, Linux has built-in security mechanisms. Files and directories have permissions associated to them; as a result, some cannot be accessed by the normal user; (see Section Permissions and Ownership). DOS, on the contrary, will let you wipe out the entire contents of your hard disk;
• there's a special user called ``root'': the system administrator, with full power of life and death on the machine. If you work on your own PC, you'll be root as well. Working as root is dangerous: any mistake can seriously damage or destroy the system just like with DOS/Win. Don't work as root unless absolutely necessary;
• much of the complexity of Linux comes from its extreme configurability: virtually every feature and every application can be tailored through one or more configuration files. Complexity is the price to pay for power;
• redirection and piping are a side DOS feature, a very inportant one and much more powerful under Linux. Simple commands can be strung together to accomplish complex tasks. I strongly suggest that you learn how to use them.

Getting Help

There are many ways to get help with Linux. The most important are:

• reading the documentation---I mean it. Although the HOWTO you are reading may serve as an introduction to Linux, there are several books that you really should read: Matt Welsh's ``Linux Installation and Getting Started'' ( http://sunsite.unc.edu/mdw/LDP/gs/gs.html ), Larry Greenfield's ``Linux User Guide'' ( ftp://sunsite.unc.edu/pub/Linux/docs/linux-doc-project/users-guide), and the Linux FAQ ( http://sunsite.unc.edu/mdw/FAQ/Linux-FAQ.html). Feel a guilty conscience until you have read at least one of them;
• the documentation of the packages installed on the machine is often found in subdirectories under /usr/doc/;
• to get some help about the ``internal commands'' of the shell, type help or, better, man bash or info bash;
• to get help on a command, type man command that invokes the manual (``man'') page pertinent to command. Alternatively, type info command that invokes, if available, the info page pertinent to command. Info is a hypertext-based documentation system, perhaps not intuitive to use at first. Finally, you may try apropos command or whatis command. With all of these commands, press `q' to exit.

1.3 Conventions

Throughout this work, examples will often follow the following format: <...> is a required argument, while [...] an optional one. Example:

$ tar -tf <file.tar> [> redir_file]

file.tar must be indicated, but redirection to redir_file is optional.

``RMP'' means ``please Read the Man Pages for further information''. I can't stress enough how important reading the documentation is.

When the prompt of a command example is `#', the command can only be performed by root.