Few basic questions related to Linux answered here. This FAQ is inspired by by David Merrill's work, with assistance and comments from Linux users all over the world. Over the years it has passed through several hands, and I'd like to recognize all the folks who have worked on it.
Special thanks are due to Matt Welsh, who moderated news:comp.os.linux.announce and news:comp.os.linux.answers, coordinated the HOWTO's and wrote substantial portions of many of them, Greg Hankins the former Linux Documentation Project HOWTO maintainer, Lars Wirzenius and Mikko Rauhala, the former and current moderators of news:comp.os.linux.announce, Marc-Michel Corsini, who wrote the original Linux FAQ, and Ian Jackson, the previous FAQ maintainer. Thanks also to Roman Maurer for his many updates and additions, especially with European Web sites, translations, and general miscellany.
Last but not least, thanks to Linus Torvalds and the other contributors to Linux for giving us something to talk about!
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FAQs -
What is Linux ?
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Linux runs on almost every general-purpose computer made in the last 10 years. It runs on systems as small as PDAs (for example, the Sharp Zaurus) and on systems as large as IBM mainframes. There are Linux distributions specifically for mobile and handheld platforms. Information on the Linux distribution for the Compaq iPAQ is at http://www.handhelds.org. Linux was written originally for Intel processor based PC's, using the hardware facilities of the 80386 processor and its successors to implement its features. The 80386 family includes the 80486 and all of the Pentium chips. However, there are now many ports to other hardware platforms. Currently it supports more than 12 archs.  |
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What is Linux ?
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At any given time, there are several "stable" versions of Linux, and one "development" version. Unlike most proprietary software, older stable versions continue to be supported for as long as there is interest, which is why multiple versions exist. Linux version numbers follow a longstanding tradition. Each version has three numbers, i.e., X.Y.Z. The "X" is only incremented when a really significant change happens, one that makes software written for one version no longer operate correctly on the other.This happens very rarely -- in Linux's history it has happened exactly once. The "Y" tells you which development "series" you are in.A stable kernel will always have an even number in this position, while a development kernel will always have an odd number. The "Z" specifies which exact version of the kernel you have, and it is incremented on every release. The current stable series is 2.6.x, and the current development series is 2.6.x. However, many people continue to run 2.4.x and even 2.2.x kernels, and they als o continue to receive bugfixes. The development series is the code that the Linu x developers are actively working on, which is always available for public viewing, testing, and even use, although production use is not recommended! This is part of the "open source development" method. Eventually, the 2.5.x development series has been "sprinkled with holy penguin pee" and became the 2.6.0 kernel and a new stable series will then be established, and a 2.7.x development series begun. Or, if any really major changes happen, it might become 3.0.0 instead, and a 3.1.x series begun. |
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FAQs -
What is Linux ?
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If you need or want to configure and compile your own kernel, the web page at http://www.kernel.org/ lists the current versions of the development and production kernels.
If you want to download the source code, FTP to ftp.xx.kernel.org, where xx is the two-letter Internet domain abbreviation of your country; e.g., us for United States, ca for Canada, or de for Germany. Kernel versions 2.2.x are archived in the directory pub/linux/kernel/v2.2, as are patches for the prerelease versions. The kernel source code is archived as a .tar.gz file, and as a .tar.bz2 file.
Follow the instructions in any of the standard references to compile the kernel, as you would with any other custom kernel. The Documentation subdirectory contains information by the authors of various subsystems and drivers, and much of that information is not documented elsewhere.
If you want to participate in kernel development, make sure that you sign on to the linux-kernel mailing list to find out what people are working on. Refer to the answer: What Mailing Lists Are There?.
There is a story about the features of the 2.4 series kernels at http://features.linuxtoday.com/stories/8191.html. |
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What is Linux ?
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Run this command: $ uname -a |
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FAQs -
What is Linux ?
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Linux supports a few dozen USB devices at present, and work is underway to develop additional device drivers. There is a Web page devoted to the subject, at http://www.linux-usb.org. There is also LDP documentation at http://tldp.org |
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FAQs -
What is Linux ?
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The name "Linux" is used to refer to three similar yet slightly different things, which can be confusing to all but the hardcore geek. The three usages vary by how much of a complete software system the speaker is talking about. At the lowest level, every Linux system is based on the Linux kernel — the very low-level software that manages your computer hardware, multi-tasks the many programs that are running at any given time, and other such essential things. These low-level functions are used by other programs, so their authors can focus on the specific functionality they want to provide. Without the kernel, your computer is a very expensive doorstop. It has all of the features of a modern operating system: true multitasking, threads, virtual memory, shared libraries, demand loading, shared, copy-on-write executables, proper memory management, loadable device driver modules, video frame buffering, and TCP/IP networking. Most often, the name "Linux" is used to refer to the Linux Operating System. An OS includes the kernel, but also adds various utilities — the kinds of programs you need to get anything done. For example, it includes a shell (the program that provides a command prompt and lets you run programs), a program to copy files, a program to delete files, and many other odds and ends. Some people honor the request of Richard Stallman and the GNU Project, and call the Linux OS GNU/Linux, because a good number of these utility programs were written by the GNU folks. Finally, software companies (and sometimes volunteer groups) add on lots of extra software, like the XFree86 X Window System, Gnome, KDE, games and many other applications. These software compilations which are based on the Linux OS are called Linux distributions. So, there are three Linuxes: the Linux kernel, the Linux OS, and the various Linux distributions. Most people, however, refer to the operating system kernel, system software, and application software, collectively, as "Linux", and that convention is used in this FAQ as well. See also the Wikipedia articles on the Linux kernel and the Linux operating system. |
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FAQs -
What is Linux ?
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Officially an operating system is not allowed to be called a Unix until it passes the Open Group's certification tests, and supports the necessary API's. Nobody has yet stepped forward to pay the large fees that certification involves, so we're not allowed to call it Unix. Certification really doesn't mean very much anyway. Very few of the commercial operating systems have passed the Open Group tests. |
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What is Linux ?
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Linus Torvalds and a loosely knit team of volunteer hackers from across the Internet wrote (and still are writing) Linux from scratch. |
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What is Linux ?
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Linus has placed the Linux kernel under the GNU General Public License, which basically means that you may freely copy, change, and distribute it, but you may not impose any restrictions on further distribution, and you must make the source code available. This is not the same as Public Domain. See the Copyright FAQ, ftp://rtfm.mit.edu/pub/usenet/news.answers/law/copyright, for details. Full details are in the file COPYING in the Linux kernel sources (probably in /usr/src/linux on your system). There is a FAQ for the GPL at: http://www.gnu.org/copyleft/gpl-faq.html. The licenses of the utilities and programs which come with the installations vary. Much of the code is from the GNU Project at the Free Software Foundation, and is also under the GPL. Some other major programs often included in Linux distributions are under a BSD license and other similar licenses. |
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What is Linux ?
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This question produces an outrageous amount of heated debate. If you want to hear Linus himself say how he pronounces it, download english.au or swedish.au from ftp://ftp.funet.fi/pub/Linux/PEOPLE/Linus/SillySounds/. If you have a sound card or the PC-speaker audio driver you can hear them by typing $ cat english.au >/dev/audio The difference isn't in the pronunciation of Linux but in the language Linus uses to say, "hello". For the benefit of those who don't have the equipment or inclination. Linus pronounces Linux approximately as Leenus, where the ee is pronounced as in "feet," but rather shorter, and the u is like a much shorter version of the French eu sound in peur (pronouncing it as the u in "put" is probably passable). |
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What is Linux ?
