Linux operating system (Linux) is a computer operating system. The name of the kernel of the Linux operating system is also "Linux". The Linux operating system is also the most famous example of the development of free software and open source.
Strictly speaking, the word Linux itself only refers to the Linux kernel, but in fact people have become accustomed to using Linux to describe the entire operating system based on the Linux kernel and using various tools and databases of the GNU Project ( Also known as GNU/Linux). Linux software based on these components is called a Linux distribution. Generally speaking, a Linux distribution package contains a large number of software, such as software development tools, databases, web servers (such as Apache), X Window, desktop environments (such as GNOME and KDE), office suites (such as OpenOffice.org), etc. .
The Linux kernel was originally designed for the Intel 386 microprocessor. The Linux kernel now supports a variety of hardware devices from personal computers to mainframes and even embedded systems.
In the beginning, Linux was just a product of personal enthusiasm. But now, Linux has become an operating system that has received widespread attention and support. Some computer industry giants, including IBM and Hewlett-Packard, have also begun to support Linux. Many people believe that compared with other commercial Unix systems and Microsoft Windows, Linux as a free software has the advantages of low cost, high security, and more reliability.
Overview
Most operating systems based on the Linux kernel use a large amount of GNU software, including a shell program, tools, libraries, compilers and tools, and Many other programs, such as Emacs. Because of this, Dr. Richard Matthew Stallman, the founder of the GNU project, proposed renaming the Linux operating system GNU/Linux. But some people just call the operating system "Linux".
Most systems also include programs that once ran on BSD, such as XFree86, which provides a GUI interface.
With the exception of some experts, most people don't choose every component or set up their own, but use the Linux package directly.
In 1983, Richard Stallman founded the GNU Project. One goal of this project is to develop a completely free Unix-like operating system. Since the launch of this project in the 1990s, GNU has begun to produce or collect a large number of necessary components for various systems, such as libraries, compilers, debuggers, and text editors. Text editors, web servers, and a Unix user interface (Unix shell) - except for the execution core (kernel) is still missing. In 1990, the GNU plan began to develop the system core based on the Mach microkernel architecture, also known as GNU Hurd. However, this Mach-based design was extremely complex and the development progress was relatively slow.
The Linux kernel was originally written by Finnish Linus Torvalds as a personal hobby when he was a student at the University of Helsinki. At that time, he was not satisfied with Minix, an operating system used for teaching. . In the initial vision, Linux was an operating system similar to Minix. The first version of Linux was released on the Internet in September 1991 by Ari Lemmke, a university FTP server administrator. Initially, Torvalds called the core "Freax", which means "free" and "freak" ), and appended the commonly used letter "X" to match the so-called Unix-like system.
However, the FTP server administrator felt that the original name "Freax" was not pleasant, so he changed the name of the core to "Linux". At that time, there were only 10,000 lines of code, and it still had to be executed on the Minix operating system, and it had to be booted from a hard disk; Then the second version (version 0.02) was released in October. At the same time, this college student from Helsinki, Finland posted a message on comp.os.minix:
Hello everybody out there using minix-< /p>
I'm doing a (free) operation system (just a hobby,
won't be big and professional like gnu) for 386(486) AT clones.
History
The history of Linux is closely linked to GNU. The GNU project, started in 1983, is committed to developing a free and complete Unix-like operating system, including software development tools and various applications. By the time the Linux kernel was released in 1991, GNU had almost completed the development of various necessary software except the system kernel. Thanks to the efforts of Linus Torvalds and other developers, GNU components can run on the Linux kernel. The entire kernel is based on the GNU General Public License, also known as GPL (GNU General Public License, GNU General Public License), but the Linux kernel is not part of the GNU project. In March 1994, Linux version 1.0 was officially released, and Marc Ewing established Red Hat Software Company and became one of the most famous Linux distributors.
Unix & Linux History The early Linux boot loader used LILO (Linux Loader), which had some intolerable flaws, such as the inability to recognize hard drives other than 8G. Later, GRUB was added (GRand Unified Bootloader) overcomes these shortcomings and has the function of 'dynamically searching core files', which allows you to edit your boot configuration system files when booting, and load Linux through the ext2 or ext3 file system. Kernel.
The logo and mascot of Linux is a penguin named Tux. The origin of the logo is because Linus was bitten by a penguin in the zoo when he was in Australia, so he chose the penguin as the Linux operating system. logo. Linux is a registered trademark owned by Linus Torvalds. This is because in 1996, a lawyer named William R. Della Croce began to send letters to various Linux publishers, stating that he owned the ownership of the Linux trademark and requiring each publisher to pay royalties. These publishers collectively appealed and demanded Reassign the registered trademark to Linus Torvalds. Linus Torvalds has repeatedly stated that Linux is free and he can sell it, but Linux must not be sold.
Some versions of Linux are versions that can be used without installation. They are called LiveCD.
User group
Promotional graphics designed by GNU/Linux enthusiasts and licensed under the GPL
Stereoscopic graphics designed by the GNU/Linux community and licensed under the GPL Traditional Linux users generally install and set up their own operating system, and they tend to be more experienced than users of other operating systems, such as Microsoft Windows and Mac OS. These users are sometimes called "hackers" or "geeks."
However, as Linux becomes more and more popular, more and more original equipment manufacturers (OEMs) begin to pre-install Linux on the computers they sell. Among Linux users, there are also ordinary computer users, and Linux systems also begin to slowly seize the market. Desktop computer operating system market. At the same time, Linux is also one of the most popular server operating systems. Linux also has an advantage in the embedded computer market, and its low cost makes Linux popular among users. The main cost of using Linux is the cost of transplantation, training and learning. In the early days, because there were fewer people who could use Linux, the cost was higher. However, with the increasing popularity of Linux and the increasing number of software on Linux, the cost has become more and more expensive. More, more and more convenient and reduced.
Desktop systems such as KDE and GNOME make Linux more like an operating system such as Mac or Windows, providing a complete graphical user interface, unlike other systems that use the Command Line Interface (CLI) Unix-like operating system.
The direction of the future software industry
Linux, as an earlier open source operating system, will lead the direction of future software development.
Based on the open source nature of Linux, more and more large and medium-sized enterprises and governments are investing more resources in developing Linux. In today's world, many countries are gradually moving computers in government agencies to Linux, and this situation will continue. The widespread use of Linux has saved government agencies a lot of money and reduced concerns about the potential security of closed source software.
The English pronunciation of Linux
According to Torvalds, the pronunciation of Linux rhymes with "Minix".
The pronunciation of "i" in "Li" is similar to the pronunciation of "i" in "Minix", while the pronunciation of "u" in "nux" is similar to the pronunciation of "o" in the English word "profess" pronounce. According to the International Phonetic Alphabet it should be ['linэks].
There is an audio of Torvalds himself speaking, and the audio content is "Hello, this is Linus Torvalds, and I pronounce Linux as Linux".
Application
KDE desktop environment running on SUSE. In the past, Linux was mainly used as a server operating system, but its cheapness, flexibility and Unix background make it suitable for a wider range of applications. Traditionally, the Linux-based "LAMP (a combination of Linux, Apache, MySQL, Perl/PHP/Python)" technology has been widely popular among the developer community and is also the most commonly used by current website service providers. platform.
Based on its low cost and high degree of configurability, Linux is often used in embedded systems, such as set-top boxes, mobile phones, and mobile devices. On mobile phones, Linux has become the main competitor of Symbian OS; on mobile devices, it has become an alternative to Windows CE and Palm OS. The currently popular TiVo digital cameras use customized Linux. In addition, there are many hardware-based network firewalls and routers, such as some LinkSys products, which are driven internally by Linux and use the firewall and routing functions provided by the operating system.
More and more supercomputers use Linux. According to the November 2005 issue of the TOP500 supercomputer list, the two fastest groups of supercomputers in the world currently use Linux as their operating system. Among the 500 systems listed in the table, 371 groups (or 74.2%) use Linux as the operating system. Among the top ten, 7 groups use Linux.
The SONY PlayStation 3, which was launched in 2006, also uses the Linux operating system. Previously, Sony had also launched a DIY package called PS2 Linux for their PlayStation 2.
As for game developers Atari and id Software, they have launched Linux desktop versions of their games. In addition, Linux Game Publishing also specializes in writing games for the Linux platform, and is committed to porting other game program codes compiled on the Windows platform to the Linux platform, and providing licenses for ported games.
A project called One Laptop Per Child (OLPC), which aims to provide laptops to all children living in developing countries, uses Linux as the default operating system.
Distributions
Linux is primarily used as part of a Linux distribution (often called a "distro"). These distributions are written by individuals, loosely organized teams, as well as commercial and volunteer organizations. They usually include other system software and application software, as well as an installation tool to simplify the initial installation of the system, and an integrated manager to allow software installation and upgrade. Distributions are made for many different purposes, including support for different computer architectures, localization for a specific region or language, real-time applications, and embedded systems, and many even intentionally include only free software. Currently, more than three hundred distributions are actively developed, with about a dozen of the most commonly used distributions.
A typical Linux distribution includes: the Linux kernel, some GNU libraries and tools , a command-line shell, a graphical interface for the X Window System and corresponding desktop environments such as KDE or GNOME, and contains thousands of application software from office suites, compilers, text editors to scientific tools.
Outlook
A project called One Laptop Per Child (OLPC), which aims to provide laptops to all children living in developing countries, uses Linux as a tool for shortcomings. Provincial operating system.
The beginning of chaos
It was 1991, and the painful Cold War was gradually coming to an end. An air of peace and tranquility began to rise over the horizon. In the field of computing science, with the introduction of powerful hardware, the ultimate capabilities of computers have exceeded our imagination, and a brilliant future seems to be beginning to emerge.
But something is still missing. In the field of operating systems, there is a large void.
On the one hand, DOS also rules the huge personal computer kingdom. Bill Gates bought DOS from a Seattle hacker for $,000. After that, relying on smart marketing strategies, this simple operating system quietly penetrated into every corner of the world. PC users have no other choice. Although the Apple machine was good, no one could afford its sky-high price. It remains far removed from popular demand.
Another camp in the computing world is the UNIX world. But UNIX is even more expensive. In pursuit of high profits, UNIX vendors raise prices high enough to scare away any PC user. Bell Labs has generously provided UNIX source code to universities. But now, these source codes are carefully guarded and no longer open to the public. What makes PC users around the world even more upset is that the big players in the software market have failed to provide an effective solution to this problem.
MINIX seems to be an option. It was written from scratch by Andrew S. Tanenbaum, an American who is a professor in the Netherlands. The original intention of MINIX was to teach students the inner workings of operating systems. MINIX was designed for the most popular Intel 8086 microprocessor at the time.
As an operating system, MINIX is not top-notch. But the good thing about it is that you get its source code. As long as you have the book "Operating Systems: Design and Implementation" written by Tanenbaum, you can get the 12,000 lines of source code written in C and assembly. For the first time, programmers or hackers had the opportunity to read the operating system's source code -- something closely guarded by software vendors. Tanenbaum explores the art of writing operating systems in detailed and concise terms. He was a first-rate author who captivated some of the brightest minds in the computer field at the time.
Computer students all over the world are studying this book and understanding the MINIX operating system running on their computers by reading its source code.
Linus Torvalds is one of these students.
Falling to the ground
In 1991, Linus Benedict Torvalds was still a Finnish student, studying computer science in his second year at the University of Helsinki. He is also a self-taught hacker. This handsome 21-year-old Finnish guy with beach yellow hair and a soft-spoken voice loves to tinker with his computer and push it to its limits. But he lacked a suitable operating system to meet his such professional needs. MINIX is good, but it is only suitable for students. It is a teaching tool, not a powerful practical system. At that time, programmers around the world were very optimistic about Richard Stallman's GNU project - a movement dedicated to launching free, high-quality software. In the realm of computing science, Stallman is a revered mythical hero. His admirable career began at the famous MIT Artificial Intelligence Laboratory. In the mid-to-late 1970s, he developed the famous Emacs editor there. In the early 1980s, commercial software companies attracted most of the best programmers from artificial intelligence laboratories and signed strict confidentiality contracts with them. Stallman was very unhappy about this. He believed that software, unlike other products, should not be subject to any restrictions on copying and modification. Only in this way can we develop better and more powerful software. In 1983, he announced the launch of the GNU project to the world in the famous "GNU Manifesto" and began the free software movement to implement his philosophy (Note: the word GNU is the recursive abbreviation of 'GNU's Not Unix'). In order to finally realize his dream of developing a free operating system, he had to create some tools. So, in early 1984, Stallman began to create a work that impressed commercial enterprise programmers---the GNU C compiler (gcc). His superb technical genius puts all commercial software programmers to shame. gcc is recognized as one of the most efficient and robust compilers in the world.
By 1991, the GNU project had developed numerous tool software. The long-awaited GNU C compiler has also been released. But free operating systems weren't around yet. MINIX was also subject to copyright (later, in April 2000, Tanenbaum released the free MINIX under the BSD license). The GNU operating system kernel ---HURD --- is still under development and may not be available for a few years.
After putting it off for so long, it’s finally time to talk about Linus.
On August 25, 1991, Linus posted a historic post on the MINIX news group...
From: torvalds@klaava.Helsinki.FI (Linus Benedict Torvalds)
Newsgroups: comp.os.minix
Subject: What would you like to see most in minix?
Summary: small poll for my new operating system< /p>
Message-ID: <1991Aug25.205708.9541@klaava.Helsinki.FI>
Date: 25 Aug 91 20:57:08 GMT
Organization: University of Helsinki
Hello, friends who use minix,
I am writing a (free) operating system based on a 386 (486) AT machine (just as a hobby, I don’t know how to do it) (as big as gnu and as professional as gnu). I started brewing it in April and it’s almost done now.
Now I want to know some of your opinions on minix. What is good about it? What's not good? Because my operating system is somewhat similar to minix (the file system uses the same physical layout (for practical reasons, there are similarities in other aspects)). I've ported bash (1.08) and gcc (1.40) and they work fine. This means that over the next month I will be adding more practical features to it. So I want to know what features everyone wants it to have. Suggestions are welcome, but I can't guarantee that your suggestions will be implemented :-)
Linus (torvalds@kruuna.helsinki.fi)
P.S. Yes, it does not include Any minix code, and it has a multi-threaded file system. It cannot run on other hardware now (because of the use of 386 task switching mechanism, etc.), and except for AT hard drives, it basically does not support any other hardware. That's all:-(.
It is easy to see from this post that Linus himself did not expect that his little creation would change the entire field of computing science. In mid-September 1991, Linux version 0.01 came out , and was put online. It immediately attracted people's attention. The source code was downloaded, tested, modified, and finally reported to Linus on October 5, accompanied by Linus' famous statement: < /p>
From: torvalds@klaava.Helsinki.FI(Linus Benedict Torvalds)
Newsgroups: comp.os.minix
Subject: Free minix-like kernel sources for 386-AT
Message-ID: <1991Oct5.054106.4647@klaava.Helsinki.FI>
Date: 5 Oct 91 05:41:06 GMT
Organization: University of Helsinki
Are you nostalgic for the good old days of the minix-1.1 era? At that time, you wrote the driver yourself and were full of a sense of accomplishment. There are no good projects to do now, are you? Trying to chew on an operating system and modify it to meet your own needs, right? Now that there is nothing you need to improve in minix, you feel disappointed, right? There is no chance to stay up all night to improve a small program, right? If so, then this post is for you
:-) A month(?) ago I mentioned that I was developing a free version of An operating system similar to minix. Now it's finally out (although it may not live up to your expectations). I'd love to make the source code available to the public so it can be disseminated more widely. It's now only version 0.02 (plus a (tiny) patch). But I have successfully run bash/gcc/gnu-make/gnu-sed/compress and other programs on it. The source program of my little baby can be found in the /pub/OS/Linux directory under nic.funet.fi(128.214.6.100). There are also some README files in this directory, as well as several executable files that can work under Linux (bash, update and gcc, what more can you ask for :-). The complete kernel source code is posted here, because the minix source program is not used in it. The source program of the function library is only partially open source, so it cannot be provided yet. After getting the source code, just compile it directly. After compiling, you can transfer it. Ha ha. The source code for the executable programs (bash and gcc) can be found in the /pub/gnu directory on the same website.
A few weeks later, Linux version 0.03 was released. In December, version 0.10 was released. Linux at this time still seemed very crude.
It can only support AT hard disks, and no login is required (bash is entered upon startup). Version 0.11 has many improvements and can support multi-language keyboards, floppy drives, VGA, EGA, Hercules, etc. The version number of Linux rose directly from 0.12 to 0.95, 0.96... Soon, the source code of Linux was spread all over the world through FTP sites in Finland and other places.
Who to compete with?
Soon, Linus began to face challenges. He was facing none other than Andrew Tanenbaum, the great teacher who developed MINIX. In a reply to Linus, Tanenbaum wrote:
"I still stand by my point of view. It was a fundamental mistake to design the core of such a monolithic architecture in 1991. You should be lucky that it was not me. student. With such a design, you won't get high marks from me:-)" (Andrew Tanenbaum to Linus Torvalds) Linus later admitted that this was the worst comment he had ever received about developing Linux. Tanenbaum was a well-known professor at the time, so what he said was naturally very important. But this time when facing Linux, his words failed because Linus was not a person who gave up easily.
Tanenbaum also declared: "Linux is obsolete."
Now it is the turn of the new Linux generation to fight back. Backed by the strong Linux community, Linus gave Tanenbaum a fitting reply:
Your job is to be a professor or researcher. This is a perfect explanation for minix's brain damage. (Linus Torvalds to Andrew Tanenbaum)
Linux development continues. Soon more than a hundred people joined the development effort, then thousands, then hundreds of thousands. Linux is no longer just a hacker's toy. With the numerous software developed by the GNU project, Linux can already enter the market. It was eventually released under the GNU Public License, which ensures that anyone has free access to its source code and can freely copy, study, and modify it. Neither students nor programmers missed this opportunity.
Soon, software vendors also arrived. Linux is a free operating system. All software vendors need to do is compile various software on the Linux platform and then organize them into a form that can be pushed to the market. This is no different from other operating systems in terms of operating mode, except that Linux is free. Redhat, Caldera, and others have gained sizable markets with users from all over the world. In addition to these commercial companies, non-commercial programming experts have also organized themselves voluntarily and launched their own brand---the world-renowned Debian. Coupled with new graphical interfaces (such as X Window System, KDE, GNOME), various brands of Linux are very popular.
A lot of good shows and surprises. In addition to PCs, Linux has been ported to many other platforms (PowerPC, Sun Sparc, ARM, Alpha...Debian supports more than a dozen CPUs). It was also installed on 3com's handheld computers. In addition, using cluster technology, many Linux single machines can be organized into a whole for parallel computing. In April 1996, researchers at Los Alamos National Laboratory used 68 Linux machines to build a parallel computing system and used it to simulate the shock wave of an atomic bomb explosion. Unlike other supercomputers, cluster computers built with Linux are very cheap. This DIY supercomputer only costs 2,000, including labor (cables to connect 68 PCs). The price is only one-tenth of that of commercial machines of the same level. Its peak calculation speed can reach 19 trillion (billion) times per second. It ranks 315th in the world supercomputer rankings. It operates stably and reliably.
Three months later, there is no need to reboot
Today, Linux's greatest advantage is the huge development enthusiasm that drives it forward. Once new hardware comes out, the Linux kernel can be quickly improved to adapt to it. For example, the Intel Xeon microprocessor has only been out for a few weeks, and the new Linux kernel has already caught up. It is also used on Alpha, MAC, and PowerPC. Linux can even be run on handheld phones, a field that few people care about. Linux is striding into the new century with the same enthusiasm as when it was born in 1991.
As for Linus himself, he keeps a simple life. Unlike Bill Gates, Linus is not a billionaire. After completing his studies, he moved to the United States and found a job at Transmeta. Transmeta launched its own Crusoe processor after guiding the development of a top-secret project. Linus is an active member of this R&D team. He recently married Tove and had a daughter named Patricia Miranda Torvalds. Linus is revered by the worldwide computing community and is by far the most popular programmer on our planet.