What is Linux?

Linux operating system is a computer operating system, which is pronounced "Rinax" in Chinese. The kernel name of the Linux operating system is also "Linux". Linux operating system is also the most famous example in the development of free software and open source.

I. Overview

[Edit this paragraph]

Linux official website www.kernel.org

Most operating systems based on Linux kernel use a lot of GNU software, including shell programs, tools, libraries, compilers and tools, as well as many other programs, such as Emacs. Because of this, Dr. richard matthew stallman, the pioneer of GNU project, proposed to rename the Linux operating system GNU/Linux. But some people just call the operating system "Linux".

Most systems also include programs that used to run in BSD, such as XFree86, which provides a GUI interface.

Except for some experts, most people don't choose each component or set it themselves, but use Linux suite directly.

1983, Richard Stallman created the GNU project. One goal of this project is to develop a completely free Unix-like operating system. Since this project was started in 1990, GNU began to produce or collect a large number of components needed by various systems, such as libraries, compilers, debuggers, text editors, web servers and Unix user interfaces (UNIX shell). From 65438 to 0990, GNU planned to develop a system core based on Mach microkernel, called GNU Hurd. However, the design based on Mach is extremely complicated and the development progress is relatively slow.

The basic idea of Linux has two points: first, everything is a file; Second, every software has a clear purpose, and at the same time, it is written as well as possible. The first is that everything in the system boils down to one file, including commands, hardware and software devices, operating systems, processes and so on. For the operating system kernel, they are all regarded as files with their own characteristics or types. As for saying that Linux is based on Unix, it is largely because their basic ideas are very similar.

Linux kernel was originally written by Finnish Linus Torvalds (the most famous computer programmer and hacker in the world today) out of personal interest when he was studying at Helsinki University. At that time, he was not satisfied with Minix, an operating system for teaching. Originally conceived, Linux was an operating system like Minix. The first version of Linux was released on the Internet in September of 199 1 by Ari Lemmke, the administrator of FTP server in university. At first Torvalds called this kernel "free", which means the combination of freedom and strangeness, and attached the common letter "X" to match the so-called UNIX-. But the FTP server administrator didn't like the original name of "Freax" and changed the name of the core to "Linux". At that time, there were only 65,438+00,000 lines of code, which still had to be executed on the Minix operating system and booted by the hard disk. Then the second version (version 0.02) was released in June 5438+10, and college students in Helsinki, Finland left a message on comp.os.minix:

Hello, everyone who uses minix-

I'm making a (free) operating system (just a hobby,

Not as big and professional as gnu) is cloning human 386(486).

Second, history.

The history of Linux is closely related to GNU. Since 1983, GNU project has been devoted to developing a free and complete Unix-like operating system, including software development tools and various applications. By the time 199 1 released the Linux kernel, GNU had almost completed the development of all kinds of necessary software except the system kernel. With the efforts of Linus Torvalds and other developers, GNU components can run on the Linux kernel. The whole kernel is based on the GNU General Public License, that is, GPL(GNU General Public License), but the Linux kernel is not part of the GNU plan. 10 in March, 1994, the Linux version 1.0 was officially released. Mark Ewing founded Red Hat Software Company and became one of the most famous Linux publishers.

Unix & In the early days of Linux history, the Linux boot loader used LILO(Linux Loader), which had some intolerable defects, such as not being able to identify hard disks other than 8G. Later, GRUB(GRand Unified Bootloader) was added to overcome these shortcomings, and it had the function of' dynamically searching for core files'. It allows you to edit your startup system files at startup and load the Linux kernel through ext2 or ext3 file systems.

The logo and mascot of Linux is a penguin named Tux. The origin of logo is that Linus was bitten by a penguin in the zoo when he was in Australia, so he chose penguin as the logo of Linux. The registered trademark of Linux belongs to Linus Torvalds. This is because in 1996, a lawyer named William R. Della Croce began to write to various Linux publishers, declaring that he owned the Linux trademark and asking them to pay royalties. These publishers collectively called for the redistribution of registered trademarks to Linus Torvalds. Linus Torvalds said many times that Linux is free and he can sell it himself, but Linux must not be sold.

Some versions of Linux distribution can be used through CD or bootable USB storage devices without installation. They are called LiveCD.

Third, user groups.

[Edit this paragraph]

A publicity map designed by GNU/Linux enthusiasts and authorized by GPL.

The GNU/Linux community designed a three-dimensional diagram and used GPL to authorize traditional Linux users to install and set up their own operating systems. They are usually more experienced than users of other operating systems such as Microsoft Windows and Mac OS. These users are sometimes called "hackers" or "geeks". However, with the increasing popularity of Linux, more and more OEMs began to pre-install Linux on the computers they sold, and Linux users also had ordinary computer users. Linux systems also began to slowly seize the desktop computer operating system market. At the same time, Linux is also one of the most popular server operating systems. Linux also has advantages in the embedded computer market, and its low cost makes Linux popular with 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 relatively high. However, with the increasing popularity of Linux and the increasing convenience of software on Linux, the cost has been reduced.

Desktop systems such as KDE and GNOME make Linux more like an operating system such as Mac or Windows, and provide a perfect graphical user interface, which is different from other Unix-like operating systems using command line interface (CLI).

Fourthly, the future development direction of the software industry.

[Edit this paragraph]

As an early open source operating system, Linux will lead the development of future software.

Based on the open source characteristics of Linux, more and more large and medium-sized enterprises and governments have invested more resources in developing Linux. In today's world, many countries gradually transfer government computers to Linux, and this situation will continue. The widespread use of Linux has saved a lot of money for government agencies and reduced concerns about the potential security of closed-source software.

English pronunciation of verb (verb) Linux

[Edit this paragraph]

According to Torvalds, the pronunciation of Linux rhymes with "Minix".

The pronunciation of "I" in "Li" is similar to that of "I" in "Minix", and the pronunciation of "U" in "nux" is similar to that of "O" in English word "profess". According to the International Phonetic Alphabet, it should be ['Lin э ks]-similar to "Linacos".

There is an audio of Torvalds himself. The audio content is "Hello, I am linus Torvalds, and I pronounce Linux as Linux".

Download address /Linux- Pronunciation (link invalid)

Application of intransitive verbs

[Edit this paragraph]

In the past, Linux was mainly used as the operating system of servers, but because of its cheapness, flexibility and Unix background, it is suitable for a wider range of applications. Traditionally, there is a classic combination based on Linux, "LAMP (combination of Linux, Apache, MySQL, Perl/PHP/Python)", which provides a complete set of website erection support including operating system, database, website server and dynamic webpage. But for large-scale fields, such as Oracle, DB2, PostgreSQL, Tomcat JSP of Apache, etc. , there are good application examples on Linux. Besides being popular among developers, it is also the most commonly used platform for web service providers.

Because of its low cost and high settability, Linux is often used in embedded systems, such as set-top boxes, mobile phones and mobile devices. On mobile phones, Linux has become one of the three major smartphone operating systems alongside Symbian OS and Windows Mobile. On mobile devices, it becomes a substitute for Windows CE and Palm OS. At present, the popular TiVo digital camera uses customized Linux. In addition, there are many hardware-based network firewalls and routers, such as some LinkSys products, which are internally driven by Linux and use the firewall and routing functions provided by the operating system.

There are more and more supercomputers using Linux. According to the list of top 500 supercomputers in issue 1 1 in 2005, the two fastest supercomputers in the world both use Linux as their operating systems. Among the 500 listed systems, 37 1 group (74.2%) uses Linux as the operating system, and seven of the top ten use Linux.

Sony PlayStation 3 launched in 2006 also uses Linux operating system. Previously, Sony also launched a DIY component called PS2 Linux for their PlayStation 2. As for game developers Atari and id Software, they have both launched Linux desktop versions for their games. In addition, Linux Game Publishing also specially writes games for Linux platform, devotes itself to transferring other game program codes compiled on Windows platform to Linux platform, and provides authorization for portable games.

A project called "One Laptop per Child (OLPC)" aims to provide laptops for all children living in developing countries. This project uses Linux as the default operating system.

Seven. Distribution edition

[Edit this paragraph]

Linux is mainly used as part of the Linux distribution (usually called "distro"). These distributions are written by individuals, loosely organized teams, and commercial and volunteer organizations. They usually include other system software and application software, as well as installation tools to simplify the initial installation of the system and integrated managers to upgrade the software installation. Distribution has many different purposes, including supporting different computer structures, localization of specific regions or languages, real-time applications and embedded systems, and even many versions deliberately add only free software. At present, there are more than 300 distributions under active development, of which about 12 are the most commonly used.

A typical Linux distribution includes: Linux kernel, some GNU libraries and tools, command-line shell, X Window system with graphical interface and corresponding desktop environment, such as KDE or GNOME, and includes thousands of applications from office suites, compilers, text editors to scientific tools.

At present, the most famous distributions are Debian, redhat, ubuntu, Suse, Mandriva (formerly Mandrake), CentOS, fedora and so on.

Red Flag linux, a well-known linux version in China.

8. The difference between 8.Linux and other operating systems

[Edit this paragraph]

Linux can be stored on the same machine as other operating systems such as MS-DOS, OS/2 and Windows. They are all operating systems, each with some characteristics, but each with its own characteristics and differences.

At present, the operating systems running on PC mainly include MS-DOS of Microsoft, Windows, Windows NT and OS/2 of IBM. Early PC users generally used MS-DOS, because this operating system did not require high hardware configuration of the machine. With the rapid development of computer hardware technology, the price of hardware equipment is getting lower and lower, and people can improve the hardware configuration of computers relatively easily, so they start to use operating systems with graphical interfaces such as Windows and Windows NT. Linux is an operating system that people pay attention to recently, and it is gradually accepted by PC users. So, what are the main differences between Linux and other operating systems? The following is discussed from two aspects.

The difference between Linux and MS-DOS

It is common to run Linux and MS-DOS on the same system. As far as processor function is concerned, MS-DOS does not fully realize the function of x86 processor, while Linux runs in processor protection mode, which gives full play to all the characteristics of the processor. Linux can directly access all available memory in the computer and provide a complete Unix interface. While MS-DOS only supports some Unix interfaces.

As far as the functions of the operating system are concerned, MS-DOS is a single-task operating system. Once users run MS-DOS applications, they monopolize the resources of the system, and it is impossible for users to run other applications at the same time. Linux is a multitasking operating system, and users can run multiple applications at the same time.

Differences between Linux and OS/2, Windows and Windows NT

From the development background, the difference between Linux and other operating systems is that Linux is developed from a relatively mature operating system, while other operating systems, such as Windows NT, are self-contained and have no corresponding operating system. This difference enables Linux users to benefit greatly from the contribution of Unix groups. Because Unix is one of the most widely used and mature operating systems in the world, it is a multi-task system of microcomputers and supercomputers developed in the mid-1970s. Although the interface is sometimes confusing and lacks relatively centralized standards, it has developed into one of the most widely used operating systems. Unix authors and users agree that only Unix is the real operating system. Many computer systems (from personal computers to supercomputers) have Unix versions, and Unix users can get support and help from many aspects. Therefore, Linux, as a clone of Unix, will also get corresponding support and help, and directly have a firm position established by Unix among users.

The difference between Linux and other operating systems is that Linux is an open and free operating system, while other operating systems are closed and need to be paid. This difference enables us to get many versions of Linux and the application software developed for it without spending money. When we access the Internet, we will find that almost all available free software can run on Linux system. Many software vendors provide various Unix implementations. The development and developers of Unix promote its standardization in an open system way, but no company controls this design. Therefore, any software vendor (or pioneer) can implement these standards in some Unix implementations. Operating systems such as OS/2 and Windows NT are copyrighted products, and their interfaces and designs are controlled by one company, and only these companies have the right to realize their designs. They grew up in a closed environment.

Nine. Applications and views

[Edit this paragraph]

We may not have to discuss how tempting the opening of LINUX source code has brought us. We only study how LINUX can help our lives here. We just need to master the most basic application of LINUX, as well as its installation and use. The operation of LINUX has now developed to operate under the command line and application programs like the WINDOWS desktop system. Users who don't know much about LINUX can choose desktop LINUX installation.

Here, I will sort out and post some questions and answers about LINUX from the internet, hoping to help those friends who want to know about LINUX.

Understand GNU/Linux. Don't use Windows standards to require Linux.

Because the word GNU/Linux is too long, "Linux" means "GNU/Linux" unless otherwise specified. In this era, I'm afraid no one needs me to introduce what Linux is. If you think that "Linux is just something similar to DOS", what is Linux next to you? Then why did I write such an article? Because, I found that there are still many people who don't understand Linux and UNIX. Although they are using it, they sometimes ask, "Why can't Linux be like Windows ...? ","Why can't Redhat Linux mount NTFS partition! " , "What is used to organize the hard disk under Linux?" "When will OpenOffice be fully compatible with Word files?" "What can Windows do now and Linux can't?" ..... They have 40G hard drives, but only 2G space is allocated to Linux, and sometimes they complain, "Why does this thing take up so many hard drives!" It seems that Windows should take up most of the hard disk. They put important data in the partition of Windows, which seems that they don't trust Linux. They are always looking for novel and beautiful GUI programs everywhere, and they are dismissive of anything on the command line. They are interested in procrastination. Drop, menu configuration, automatic upgrade are all very interested. If they find a Linux program that looks like a Windows program, they will be happy to say, "Haha! Linux can also ... "If Linux beats Windows in a test, they will jump for joy. When they can't solve problems with Linux, they even use Wine to run Windows programs. Sometimes there is no way, so we have to restart Windows, or simply save trouble and install a VMWare virtual Linux under Windows to play.

If you have the above situation, it means that your thoughts have been subtly influenced and misled by Windows. You haven't been able to understand the UNIX idea in Linux in essence. You support Linux, you like Linux, and you can feel happy from it, which is good. What you need to understand now is that Linux has never been a toy, it is a descendant of the genius UNIX. UNIX is the greatest invention since the invention of transistor, and its design has been better than that of Windows since its birth.

You have to understand what "design" means. A bad design can't be improved by later sewing, but an excellent design can not only change with constant changes, but also influence the latecomers. An excellent design plus an excellent implementation is an excellent invention. Linux is such an excellent invention.

Linux doesn't need to catch up with Windows or crush Microsoft. Its ultimate goal is to change the whole computer world, give people freedom, give people fun and convenience.

Unix is so simple that you don't need to be a genius to understand it.

Dennis ritchie, the designer of UNIX, said, "UNIX is very simple. Only a genius can understand its simplicity. " But I don't think so, because I'm not a genius, but I bravely deleted Windows completely and tried to solve things I didn't understand by UNIX instead of asking for help from Windows. Now that I have realized the ideas and benefits of UNIX, my work efficiency can be several times higher than that of Windows. Because I believe in this belief: "What Windows can do, Linux can certainly do it, and do it better." The beginning of this section should be changed to: "Unix is simple, you don't need to be a genius or a computer expert." But in this world that rejects Windows misunderstanding, you need faith and courage to understand its simplicity. "Here I tell you something I know. First of all, what you need to know is that Microsoft has no position in the international science field at all.

-

Simply put, Linux is an operating system similar to Unix, which can be used freely and spread freely. Mainly used in computers based on Intel x86 series CPU. This system is designed and implemented by thousands of programmers all over the world. Its purpose is to build a Unix-compatible product that is not restricted by any commercial software copyright and can be used freely all over the world.

The emergence of Linux first began with a computer enthusiast named Linus Torvalds, who was a student at the University of Helsinki in Finland. His aim is to design an operating system, not Minix (an operating system teaching program written by a computer professor named Andrew Tannebaum). This operating system can be used on personal computers with 386, 486 or Pentium processors, and has all the functions of Unix operating system, so the design of Linux prototype began.

Linux is famous for its high efficiency and flexibility. It can realize all the functions of Unix on PC, and has the ability of multi-task and multi-user. Linux is obtained free of charge under the license of GNU, and it is an operating system conforming to POSIX standard. Linux operating system software package includes not only a complete Linux operating system, but also application software such as text editor and high-level language compiler. It also includes an X-Windows graphical user interface with multiple window managers, which allows us to use windows, icons and menus to operate the system, just like we use Windows NT.

Linux is loved by computer enthusiasts for two main reasons. First, it belongs to free software, users can get it and its source code without paying any fees, and they can make necessary modifications according to their own needs, use it for free, and continue to spread it without restrictions. Another reason is that it has all the functions of Unix, and anyone who uses Unix operating system or wants to learn Unix operating system can benefit from Linux. -1991April, Finns Linux Benedict Torvalds designed a system kernel Linux 0.0 1 which can be used on low-end computers.

But I didn't use any MINIX or UNIX source code. This is a free system published by USENET, which is mainly used on x86 computers. I hope everyone can improve together and put the source code on the FTP site in Finland for free download from generation to generation. Originally, he wanted to call this system freax, but the FTP staff thought it was Linus MINIX, so they stored Linux as a subdirectory, so it became "Linux". At this time, Linux only has core programs, so it can't be called a complete system. However, because many professional users (mainly programmers) voluntarily develop its applications and use the Internet to modify them, there are more and more programs around it, and Linux itself has gradually developed.

Running Linux requires low configuration, supports many PC peripherals, and such powerful software is completely free, and its source code is completely open and anyone can use it. Speaking of which, you may wonder, is there something hidden behind this free? Will the author be willing not to take out a penny? In fact, it represents another concept of software development: the copyright system based on GNU.

Copyright is a system established to protect the author's due interests, but it hinders the development of science and technology to some extent. For example, the virus is rampant now because Microsoft refuses to disclose the source code of Windows. Vendors of antivirus software have to delve into OLE structure by themselves. In addition, in order to maintain its dominance, Intel has formulated many hardware specifications that are not allowed to be used by other manufacturers, which makes many developers spend money and time not to upgrade technology, but to be compatible, thus causing confusion and monopoly in scientific research and development.

In order to change this situation, Richard M. Stallman established the Free Software Foundation (FSF) in 1984. He believes that unfair open source code of various software companies for their own benefit will hinder the development of human civilization, and really good software is to solve problems for others.

It should be distributed to those who need it. He developed a project called GNU, and the first set of software was GNU Emacs (a powerful editor under UNIX platform). Anyone can get this software and its source code for free, so many people spontaneously modify this software and add functions to it. In order to clarify the specifications of GNU, Stallman issued authorization statements for GNU General Public License and GNU Library General Public License. According to these statements, anyone can download, sell, copy and modify all GNU software, but the program source code must be provided or the user must know where to get the source code! But no matter whether it is free or charged, any user who obtains these softwares has the same rights as the provider.

You can give them away or sell them. Because of this authorization, GNU software snowballed and became more and more powerful. Of course, there are also bad effects. If the profits of developers decrease, no one will really develop software. After all, people still have to eat. However, with the popularity of the Internet, it is increasingly easy for people to get all kinds of.

Most software is only temporary, and will not be used again after use, so the service life of a software will be greatly shortened. In this case, the traditional electronic publishing industry should make corresponding adjustments.

The copyright of Linux kernel program belongs to Linus himself, and other applications belong to their respective authors. However, according to the GNU authorization, anyone can distribute Linux for a fee or free, and make changes according to the authorized specifications. In this way, a large number of free programs have been transplanted to Linux, including GNU Emacs, XFree86, Mozilla and other classic software, and it is still growing. Because the source code is open, anyone who uses Linux can write their own drivers after adding new hardware, so Linux has supported new hardware more than many professional UNIX systems. The success of Linux is impossible without the internet, because Linux is actually the result of joint development by many programmers all over the world.

After many modifications (including kernel upgrade and peripheral program improvement), Linux has developed into a pure 32-bit multiplexing operating system that follows POSIX standard, and a 64-bit version is also under development. Linux can be compatible with most UNIX systems, and many UNIX programs can run in Linux environment without or with little modification. Built-in TCP/IP protocol, which can be directly connected to the Internet and used as a server or terminal; Built-in JAVA interpreter can directly run JAVA source code; Have the ability of programming language development, text editing and typesetting, database processing, etc. Provide the graphical interface of X window; It is mainly used in x86 series personal computers, and there are also versions of other different hardware platforms, which support all popular hardware devices.

In terms of performance, it is not weaker than Windows or even UNIX, and it can also run Windows applications through the simulator. It has thousands of applications, no less than Windows, as well as profitable software developed by commercial companies. The most valuable thing is that it is a real UNIX system, which can be used by professional users and people who want to learn UNIX on personal computers. Linux is a very flexible system. Compared with Windows, it is also a difficult system, just as most users are not used to the single-button mouse of MacOS. If you want to be familiar with Linux, you must know some relevant knowledge, the configuration of software and hardware, and it is even better to know some programs, because no one has the obligation to provide you with technical support, except to communicate with other users, you must solve the problems yourself. Of course, it doesn't need to be so complicated if it is only used for daily use. Linux will also provide you with a perfect operating environment. All you have to do is change your habits and prejudices.

Early operating systems did not have a graphical interface. Since Apple introduced the system 1.0 in 1984, personal computers have realized a real GUI (Graphical User Interface). Since then, computers have become more friendly and easy to use. Windows graphics began with Windows 3. 1/3.2, and it was not until the appearance of Windows 95 that the multimedia era came. From then on, computers can talk and sing. Linux started from UNIX, but shine on you is better than Blue. It also has a vulgar graphical user interface, which is more stable and beautiful, comparable to the most beautiful operating system that has ever appeared in the world! Different from XP now, the graphical interface of Linux is console-based, similar to that of Windows 95 on DOS. The graphical interface of Linux is X Windows system (different from MS Windows).

X Windows is a live processing window system for UNIX, which has good portability, diversity of color control and transparency of inter-network operation. It works in a different way from Microsoft's Windows, but both of them use graphical interface and window technology. From the appearance, they are somewhat similar, but there are huge differences. In fact, the interface of X Windows is more diverse, more beautiful and more efficient. Just like the position of Windows to DOS, X Windows has changed the monotonous text interface of UNIX/Linux and provided a friendly graphical user interface (GUI).