This is a book about Linux, a freely available clone of the Unix operating system whose uses range from embedded systems and personal data assistants (PDAs) to corporate servers, web servers, and massive clusters that perform some of the world's most difficult computations.
Whether you are using Linux for personal software projects, for a small office or home office (the so-called SOHO environment), to provide services to a small group of colleagues, or to administer a site responsible for millions of email and web connections each day, you need quick access to information on a wide range of tools. This book covers all aspects of administering and making effective use of Linux systems. Among its topics are booting, package management, and the configuration of the GNOME and KDE desktops. But foremost in Linux in a Nutshell are the immeasurable utilities and commands that make Linux one of the most powerful and flexible systems available.
In addition to the tools and features written specifically for it, Linux has inherited many from the Free Software Foundation's GNU project, the Berkeley Software Distribution (BSD), the X Window System (XFree86), and contributions from major corporations as well as the companies that created the major Linux distributions. More recent projects extend Linux in exciting ways, some through changes to the kernel and some through libraries and applications that radically change the user's experience; the GNOME and KDE desktops are the most prominent examples.
This book is a quick reference for the basic commands and features of the Linux operating system. As with other books in O'Reilly's "In a Nutshell" series, this book is geared toward users who know what they want to do and have some idea how to do it, but can't always remember the correct command or option.
0.1. Other Resources
This book doesn't tell you how to install and come up to speed on a Linux system. For that, you will probably want O'Reilly's Learning Red Hat Linux, which contains a Linux distribution on CD-ROM and provides help with installation and configuration. Alternatively, Running Linux is an in-depth guide suitable for all major distributions. For networking information, check out the Linux Network Administrator's Guide. In addition to these and other Linux titles, O'Reilly's wide range of Unix, X, Perl, and Java titles may also be of interest to the Linux user.
0.1.1. Online Documentation
The Internet is full of information about Linux. One of the best resources is the Linux Documentation Project at http://www.tldp.org (or one of the dozens of mirror sites around the world), which has numerous short guides called HOWTOs, along with some full manuals. For online information about the GNU utilities covered in this book, consult http://www.gnu.org (also widely mirrored). The Free Software Foundation, which is in charge of the GNU project, publishes its documentation in a number of hard-copy and online books about various tools.
Each distribution maintains its own web site, and contains documentation for the software it provides as well as guides to maintaining your system under that distribution.
0.1.2. Web Sites
As befits a hot phenomenon, Linux is the central subject of several web sites and a frequent topic of discussion on others. Some sites offer original content; others just have links to articles posted elsewhere and threaded discussions (which can be a useful service). Among the sites frequented by Linux users are:
0.1.3. Linux Journal and Linux Magazine
Linux Journal and Linux Magazine are monthly magazines for the Linux community, written and published by a number of Linux activists. With both print editions and web sites, they offer articles ranging from novice questions and answers to kernel programming internals. Linux Journal, at http://www.linuxjournal.com, is the older magazine and is published by S.S.C. Incorporated, http://www.ssc.com. Linux Magazine is at http://www.linuxmagazine.com.
0.1.4. Usenet Newsgroups
Most people can receive Usenet news at work or through their ISPs. While this communications technology has lost ground in the past several years to web-based threaded discussions, it is still a valuable source of help and community connections on many topics. The following Linux-related newsgroups are popular:
There are also several newsgroups devoted to Linux in languages other than English, such as fr.comp.os.linux in French and de.comp.os.linux in German.
0.1.5. Online Linux Support
The freenode IRC service is an Internet relay chat network devoted to so-called "peer-directed" projects, particularly those involving free software. Some of its channels are designed to provide online Linux support services.
Internet relay chat is a network service that allows you to talk interactively on the Internet to other users. IRC networks support multiple channels where different groups of people type their thoughts. Whatever you type in a channel is seen by all other users of that channel.
There are a number of active channels on the freenode IRC network where you will find users 24 hours a day, 7 days a week who are willing and able to help you solve any Linux problems you may have, or just chat. You can use this service by installing an IRC client (some distributions install them by default), connecting to server name irc.freenode.org:6667, and joining a channel focusing on Linux, such as:
And so on. Please be sure to read up on the rules of chat etiquette before chatting. In particular, the participants in these groups tend to expect people to read documentation and do some experimentation before asking for help with a problem.
0.1.6. Linux User Groups
Many Linux User Groups around the world offer direct support to users. Typically, Linux User Groups engage in such activities as installation days, talks and seminars, demonstration nights, and purely social events. Linux User Groups are a great way of meeting other Linux users in your area. There are a number of published lists of Linux User Groups. Some of the better-known ones are:
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