Beginning Linux - Chapter 1


Shailendra Patel

This chapter includes the basic fundamentals that you must know before learning about Linux like What is Linux Kernel, UNIX, GNU etc. Also we have used a lot of sources for making the tutorials which includes:

1. Wikipedia

2. Beginning Ubuntu Linux – Apress.

UNIX is an extremely successful OS, originally developed in 1969 at Bell Labs, New Jersey, by a group of AT&T employees. Its creators, who included Ken Thompson, Dennis Ritchie, and Brian Kernighan, are ranked today as some of the most prominent personalities in computer history and are even idolized by some UNIX gurus. UNIX was, and still is, a very modern, portable, multi-tasking OS.

In the late 1970s and early 1980s, UNIX had a tremendous preeminence in academic circles. It was highly respected by computer scientists of the day and became the basis for many subsequent variants made by different companies. Operating systems such as HP-UX, Solaris, and IBM AIX were a result of those efforts.

What is GNU?
GNU is a Unix-like computer operating system developed by the GNU Project. It is composed wholly of free software. It is based on the GNU Hurd kernel and is intended to be a “complete Unix-compatible software system”. It is a recursive acronym for “GNU’s Not Unix!”, chosen because GNU’s design is Unix-like, but differs from Unix by being free software and containing no Unix code. Development of GNU was initiated by Richard Stallman(Formerly Worked At MIT in AI dept.) in 1983 and was the original focus of the Free Software Foundation (FSF), but no stable release of GNU yet exists as of May 2013. Non-GNU kernels, most famously the Linux kernel, can also be used with GNU.

According to Stallman, free software is a matter of the users’ freedom to run, copy, distribute, study, change and improve the software. More precisely, it refers to four kinds of freedom, for the users of the software:

  • The freedom to run the program, for any purpose (freedom 0).
  • The freedom to study how the program works, and adapt it to your needs (freedom 1). Access to the source code is a precondition for this.
  • The freedom to redistribute copies so you can help your neighbor (freedom 2).
  • The freedom to improve the program, and release your improvements to the public, so that the whole community benefits (freedom 3). Access to the source code is a precondition for this.
The Rise of the IBM PC… and of Microsoft
In 1981 IBM introduced the IBM PC which was a huge success that in the end it turned against its creator and undermined IBM’s market dominance. IBM, unlike it’s previous corporate culture this time, to shorten the development cycle, it chose to integrate components from different vendors instead of using proprietary components from IBM itself. One of those components was the CPU: IBM used the Intel 8088 microprocessor. This allowed other computer manufacturers to create compatible computers, collectively known as PC clones. And there was also the operating system: MS-DOS, from Microsoft. Bill Gates and his company had a brilliant idea: instead of selling their OS to IBM, they only licensed it. They thus reserved their right to license the OS to other hardware makers—namely the ones that were already cloning the IBM PC. So the only identifiable components that remained the same across all these computers were the processor and the OS. Eventually the “Wintel” duo (short for Windows and Intel) began replacing “IBM PC” as the brand of the new revolution. The dream of “a PC on every desktop” running Microsoft software spun off in a thousand directions from that point onwards.

Independence from any particular hardware provider and the freedom to license its OS to different manufacturers has been the foundation of Microsoft’s success with Windows. The hardware and the OS evolved, from XT to Pentium, and from MS-DOS to Windows, but the underlying business model remained the same (with an ever-stronger arm to force deals as Windows became more popular). Microsoft became one of the most salient examples of a closed and proprietary software business model.

The Linux kernel is a Unix-like operating system kernel used by Linux-based operating systems. It is a prominent example of free and open source software. The Linux kernel is released under the GNU General Public License version 2 (GPLv2) (plus some firmware images with various non-free licenses), and is developed by contributors worldwide. Day-to-day development discussions take place on the Linux kernel mailing list.

The Linux kernel was initially conceived and created in 1991 by Finnish computer science student Linus Torvalds. Linux rapidly accumulated developers and users who adapted code from other free software projects for use with the new operating system. The Linux kernel has received contributions from thousands of programmers.

But Linux wasn’t a complete OS. It was just a kernel, unable to do anything useful without programs running in top of it. So Linux was in search of programs already available for free that emulated the working environment of a UNIX-like computer… which was exactly what the GNU project was producing. Meanwhile the GNU project was struggling to develop a free, open source, UNIX-like kernel… which was exactly what Linus Torvalds and his crew were doing. So a perfect match was found. It is not that both teams merged into one. The GNU project continued with its development of the HURD. It’s just that for practical purposes, if one person wanted to have a complete OS, he needed both parts: the Linux kernel and the GNU applications. That was the origin of a very fruitful relationship between Linux and GNU. Today many free software advocates call the OS by the full name GNU/Linux (pronounced “GNU slash Linux”). Richard Stallman even proposed the name “Lignux” one time. It you ever come across a discussion as to whether the OS should be called “Linux” or “GNU/Linux,” you should know that the latter name is defended by the followers of Richard Stallman who think his applications are as important as the kernel itself.

Slackware – One of the first Linux distributions and the oldest in active maintenance, which intends to keep its design simple often to the detriment of its usability. First released in 1993.

Debian – A free Linux distribution that emphasizes the principles of free software and collaborative development through the Debian Constitution and a Social Contract. Debian is released with access to a load of free applications available online. It was created by Ian Murdoch in 1993, the name being a combination of Debra, the name of his girlfriend, and his own.

SuSE Linux – A Linux distribution based originally on Slackware and created by four German students in 1994. It is very popular in Europe and in academic circles. In 2004 it was acquired by Novell and later divided into a free and developmental version (openSuSE), and two commercial ones (SuSE Linux Enterprise Server and SuSE Linux Enterprise Desktop). Novell has an interoperability agreement with Microsoft (which is a source of a lot of scorn towards SuSE in the free software community) and leads several projects that aim at being friendly with Windows shops (such as the Mono project or the Evolution mail and calendar client).

Red Hat – One of the first and most popular commercial versions of Linux. First launched in 1994, Red Hat gave Linus Torvalds shares of stock when it went public, allowing him to make a small fortune (he hadn’t profited much from Linux before). In 2003 it spawned the Fedora project to take advantage of external and community developers instead of relying exclusively from internal programmers. It now sponsors both a free distribution, Fedora, and Red HatEnterprise Linux, available only through a subscription.

Mandriva – A French distribution, derived from Red Hat and formerly known as Mandrake Linux. Is very popular in France and focuses on ease of use.

CentOS – CentOS is a distribution based almost exclusively on Red Hat Enterprise Linux. As thesource code of that OS is entirely available for free, it can be packaged to create another distribution, and that’s what CentOS does after stripping it of Red Hat branding and logos. Even its version schema exactly follows that of Red Hat.

Ubuntu – A distribution based on Debian. It has also some derivatives like Kubuntu (that uses KDE instead of GNOME), Edubuntu (for the academic public), and even Goobuntu, a version developed by Google employees for internal use in the company. It was first launched in 2004 and is maintained by Canonical, a UK-based company.

Chrome OS – An OS developed by Google which is designed to work only with web applications. Based on Linux and launched in 2010, it runs only on specialized hardware.

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What is Ubuntu Linux?
Ubuntu Linux is basically an operating system based on Debian that gives it some Characteristic features. But to describe it only as an OS would be nothing short of unfair: it also has a Wide range of pre-installed applications and many more readily available at the click of the mouse, and an ever-growing user community.

As an OS Ubuntu has all the features that an operating system must possess. An OS tells your OS how to start and how to work and run various system processes and user processes, without an OS your computer would not work and will ask for a boot disk.

Ubuntu is a free and open source software, part of the larger family of Linux distributions, it uses Linux as it’s Kernel. The kernel is the portion of the OS that performs the most basic functions, such as memory and process management. Linux is an open and free kernel, strongly based on concepts first sketched up for UNIX, Linux’s honorable ancestor. That’s why it is said that Linux is a UNIX-like OS.

Because Linux is just a kernel, it usually needs other programs to run as a full OS. Different Linux distributions (or distros for short) package all the other software needed to make an OS, each with a different philosophy in mind. More often than not, there are organizations behind each distribution, and these organizations often drive the development of new packages.

Ubuntu Linux is one such distribution, but it isn’t completely original, which is to say it wasn’t created from scratch. It is in fact an adaptation of Debian. Debian has been around almost as long as Linux itself, having been founded in 1993, just two years after Linus Torvalds made his initial announcement of the Linux kernel. Debian is widely respected within the Linux community and has some claim to be the definitive Linux distribution. The Debian project was started by a computer scientist named Ian Murdock, and its name comes from a combination of his Christian name with that of his girlfriend Deborah—hence Deb-Ian. Debian is well known for its strict adherence to the spirit of free and open source software, which is embodied in the Debian Social Contract and the Debian Free Software Guidelines (DFSG). These documents lay down rules for the governance of the decentralized worldwide community that is Debian.

Debian is not, like many other Linux distributions, sponsored by any company, but rather by a non- profit organization called Software in the Public Interest. Debian is also well known for how it manages its software. Part of the Debian project is to maintain an online database and repository of software, which is available to all Internet users. Today, more than 25,000 free applications are in there, and much care has been taken to make software installation and upgrade as easy as possible.

Ubuntu is based on Debian yet it is very different. Debian is mainly for servers but Ubuntu is generally used for desktop, yet now we have Ubuntu for servers and portable devices as well. Debian issues a release after a thorough bug testing procedure, but Ubuntu is very aggressive, which allows to include more modern software though sometimes is not so stable version.

Credits: LinuxLounge

This you can find in Wikipedia etc. But why does not describe the daily use of Linux? All settings, recompiling the kernel with news...

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