Linux Primary knowledge

Source: Internet
Author: User

Introduction to Linux History

Linux is a set of free and open source Unix-like operating systems, born on October 5, 1991 (the first officially announced), by the Finnish students Linus Torvalds and later joined the many enthusiasts jointly developed.

Linux is a POSIX and UNIX-based multi-user, multitasking, multi-threaded and multi-CPU operating system. It can run major UNIX tools software, applications, and network protocols that support 32-bit and 64-bit hardware. Linux inherits the design idea of Unix as the core of network, and is a stable multi-user network operating system.

There are many different versions of Linux, but they all use the Linux kernel. Linux can be installed in a variety of computer hardware devices, such as: mobile phones, tablets, routers, video game consoles, desktop computers, mainframes, and supercomputers.

Strictly speaking, the word Linux itself only represents the Linux kernel, but in fact people have become accustomed to using Linux to describe the entire Linux kernel, and use the GNU engineering various tools and databases of the operating system.

With a simple understanding, let's meet up with the father of Linux.

The father of Linux
    • Linus Torvalds (Linus Torvalds)

Related introduction:

Linus Torvalds is known as the Father of Linux, a famous computer program clerk and Hacker. The inventor of the Linux kernel and the partner of the program. He uses personal time and equipment to create one of the most popular operating system cores in the world today, and is now employed in open source
The Code Development Lab (Osdl:open Source Development Labs, Inc.) is fully developing the Linux kernel. Linux is a peculiar operating system that is born in the network, grows in the network and mature in the network. In 1991, Linus Torvalds, a Finnish university student, sprouted the idea of developing a free UNIX operating system, when Linux was born, in order to
Not to allow this fledgling operating system to be folded, Linus Torvalds to publish his own work Linux over the Internet. From this a large number of well-known, unknown computer hackers, programmers to join the development process, a huge movement came into being
, Linux has grown up gradually. Linux starts with the requirement that all source code be made public and that no one is allowed to profit from Linux trading. However, the ideal of pure free software is unfavorable to the popularization and development of Linux, so Linux began to turn to the GPL and became the main part of the GNU camp.
To be a member. Linux with excellent design, extraordinary performance, coupled with IBM, Intel, CA, CORE, Oracle and other internationally renowned enterprises support, market share gradually expanded, gradually become one of the mainstream operating systems.

After knowing the father of Linux, let's meet liux and see what it looks like.

Linux logo

The Linux logo (mascot) is a penguin named Tux.

The source of the Penguins

1994 release of Linux Official Core 1.0, we want to Linus Torvalds think of a mascot, he remembered once in Australia, a zoo was bitten by penguins, simply Penguin as a mascot!

It is more acceptable to say that penguins represent Antarctica, and the Antarctic is a land of the world, and it does not belong to any country. This means that Linux is not owned by any commercial company, and is a technological achievement that everyone in the human race can share.

Linux history * 1969 ago: An unfinished dream: Bell,mit and GE's ' Multics ' system

The early computers were not as common as today's PCs, and he was not a normal person to touch--unless it was military or high-tech, or academic research, it was really hard to reach. Not only that, the early computer architecture is still very difficult to use, in addition to the speed of operation is not fast, operating interface is also very disturbing! Because at that time the input device only card reader, output device only printer, users can not interact with the operating system (batch type operating system).

At that time, writing the program was a pity, because the programmer had to make the program-related information hole in the read paper, and then insert the read paper jam into the reader to read the information into the host computer operation. Just this is very troublesome, if the program has a small place to write wrong, haha! Just re-punch is very miserable, plus less host, the number of users, just waiting, it takes a lot of time!

After that, due to the improvement of the hardware and the operating system, the keyboard can then be used for information input. However, in a school, after all, the host may have only one, if more people waiting to use, then how to do? We still have to wait! Fortunately, at the beginning of the 1960 's, MIT developed the so-called Compatible time-sharing system, CTSS, which allows large hosts to connect to a host by providing several terminals (terminal). To make use of the resources of the host to perform the operation. The architecture looks something like this:

Tips: This compatible time-sharing system can be said to be the ancestor of modern operating system! He can allow multiple users to use CPU resources for a certain period of time, feeling that you will feel that everyone is using the resources of the host at the same time! In fact, it's the CPU that switches between each user's work, and at the time, it was a groundbreaking technology!

This way, no matter where the host is, as long as the input and output in front of the terminal job, you can take advantage of the functionality provided by the host. However, it is important to note that at this point the terminal only has the input/output function, itself completely without any operation or software installation capabilities. In addition, the more advanced host probably can only provide 30 less than the terminal.

In order to further enhance the capabilities of mainframe, so that the host's resources can provide more users to take advantage of, so around 1965, from Bell Labs (Bell), MIT and singular Company (GE) jointly launched the Multics project, The purpose of the Multics program is to enable large hosts to achieve the goal of providing more than 300 terminal connections. However, by 1969, the project was lagging behind and funding was scarce, so although the project continued to be studied, Bale withdrew from the project. (Note: Multics has a complex, majority meaning exists.) )

Tips: Eventually Multics still have a successful development of their systems, complete historical notes can be consulted: content. Although the Multics project has not received much attention, but the talent he trained is very good! ^_^

* 1969: Ken Thompson's small File server system

The Bell Lab withdrew from the project after thinking that the Multics plan was unlikely to succeed. However, among the people who had been involved in the Multics project, some ideas had been obtained from the project, and Ken Thompson was one of them!

Thompson wanted to develop a small operating system to provide his own needs because of his own needs. At the time of development, a DEC (Digital Equipment Corporation) company launched PDP-7 just no one to use, so he is ready to work on the host system core program writing. Thompson was supposed to have no time (the fate of a family with children?) No coincidence is that, in August 1969 or so, just Thompson's wife and children went to the United States to visit relatives, so he had an extra one months to stay home to make some ideas come true!

After four weeks of struggle, he finally wrote a set of core programs in combinatorial language (assembler), including some core tools and a small file system. That system is the prototype of Unix! At that time Thompson would multics a huge complex system to simplify a lot of, so with the lab friends are nicknamed this system: UNICs. (There was no UNIX name at the time).

Thompson's file system has two important concepts, namely:

* All programs or system devices are files
* Regardless of the construction editor or affiliated files, the program written has only one purpose, and it is necessary to accomplish the goal effectively.

These concepts have a significant impact on the development of Linux in the future.

Tips: A often-heard advertising word: ' Technology always comes from human nature ', Thompson will write this UNIX core program, but is to transplant a set of "space travel" game! ^_^.

* 1973: The official Birth of Unix, Ritchie and others write the first official UNIX core in C language

Because Thompson wrote that the operating system is too good to use, so the inside of Bell Labs widely circulated, and several revisions. But because UNICs was originally written in a combination of languages, and as the 0th chapter of the introduction of computer science, the combination of language with specificity, and then the machine is not the same, so every time to install to different machines have to rewrite the combination of language, really inconvenient!

Later, Thompson worked with Ritchie to change UNICs to a higher-order programming language. The ready-made programming language had a B language. But the core performance compiled by the B language is not very good. Later Dennis Ritchie to rewrite the B language into C, and then re-rewrite and compile the core of the UNICs in C language, and finally the official version of the UNIX release!

Tips: These high-level hackers are really powerful! Because of their own needs to develop so many useful tools! C Programming language development has been successful, even has been used so far! You say you are not strong! This story also tells us, do not underestimate their potential oh! You want to do, but in real life, do not have to do one of their own to play it!

Because Bell Labs is affiliated to the US telecom company at the time, but at or at the other commercial activities, for UNIX does not support or exclusion. In addition, UNIX developers at this time are Bell Labs engineers, these engineers are certainly quite research on the program, so UNIX at this time is certainly not easy to be accepted by the General people!

In particular, because UNIX is written in the higher-order C language, compared to the combination of languages need to be closely related to the hardware, high-level C language and hardware is not so relevant! So, this change also makes it easy for UNIX to be ported to different machines!

* 1977: Important UNIX Branch: the Birth of BSD

Although Bell belongs to the T, at this time for UNIX is to take a more open attitude, in addition, UNIX is in high-level C language written, theoretically portable! That is, as long as the original UNIX source code, and for the characteristics of large host to revise the original code (source code), it is possible to migrate UNIX to another different host. So after 1973, Unix was able to work with academia to develop it! The most important contact was the collaboration with the University of Berkeley, California (Berkeley).

Bill Joy of the University of Berkeley, after acquiring the core UNIX source code, modified the version to fit his machine, adding a lot of tool software and compilers, and eventually named it Berkeley Software Distribution (BSD). This BSD is a very important branch of Unix, and Bill Joy is also the founder of the UNIX Industry ' Sun (l yang) '! Sun is the development of its own commercial UNIX version at the core of BSD development. (later can be installed in the x86 hardware architecture above FreeBSD is the BSD revision come!) )

* 1979: A surprise-caught copyright proclamation!

Due to the highly portable and powerful performance of UNIX, coupled with the absence of copyright disputes at the time, many commercial companies have started the development of UNIX operating systems, such as at-Home system V, IBM's AIX, and HP and DEC companies. has launched its own host with its own UNIX operating system.

However, as we mentioned earlier, the core of the operating system (Kernel) must be coordinated with the hardware to provide and control the hardware resources to do a good job! And in the early days every computer hardware company does not have the so-called ' agreement ' concept, so every computer company produces the hardware naturally is not the same! So they have to develop the right UNIX system for their computer hardware. Such is the case with sun, Cray and HP, which are quite famous in academic institutions. The UNIX operating system they have developed and the associated software are not able to work in other hardware architectures! In addition, since no vendor designed UNIX systems for personal computers, there was no UNIX operating system that supported PCs in the early days.

Tips: Like the functionality of a compatible time-sharing system, UNIX emphasizes the multi-worker environment! But the CPU in the early 286 PC architectures was not capable of multitasking, so no one was interested in porting UNIX to x86 's computer.

Each company's own UNIX, although the structure of the same, but really can only support their own hardware, so, the previous UNIX can only be used with the server or large workstations (Workstation) equals!

But this highly open Unix system took a big turn in the 1979-because at/T, because of business considerations, and in the context of the reality of the day, he would like to get the UNIX copyright back. As a result, at/T in the Seventh edition of Unix released in 1979, special mention is made of the ' cannot provide the original code ' for students ' strict restrictions! At the same time, it also caused the tension between the UNIX industry, and also detonated a lot of business disputes ~.

Tips:at&t This version of the developed UNIX is called System V, now known as Thoroughbred Unix refers to System V and BSD these two sets!

* 1984: Minix Birth of x86 architecture

In the 1979 copyright notice, the most influential of course is the School teaches UNIX core code related knowledge of the professor! Think, if there is no core source code, then how to teach students to understand UNIX? This is a problem for Professor Andrew Tanenbaum (Tan Ningbong). However, the school curriculum still has to continue Ah! So what?

Since the 1979 UNIX seventh edition can be ported on Intel's x86 architecture, does it mean that UNIX can be rewritten and ported to x86? In this idea, Professor Tan Ningbong himself wrote the Minix UNIX like core program! In the process of writing, in order to avoid copyright disputes, Tan Ningbong completely do not look at the UNIX core source code! and stressed that his minix must be compatible with UNIX! Tan Ningbong began writing the core program in 1984 and was finally completed in 1986, and the following year published Minix related books, combined with news groups (BBS and News).

Tips: The reason for being called Minix is because he is a mini UNIX system! ^_^.

The interesting thing about this Minix version is that he is not completely free to download on the Internet! It has to be purchased through a magnetic disc/tape! Although really cheap ~ but, after all, because there is no spread on the network, so Minix delivery speed is not very fast! In addition, the original code of Minix will be attached with the tablet when you buy it! This means that users can learn the core programming concepts of Minix. (This feature for the start-up phase of Linux, but there is a lot of relationship Oh!) )

In addition, the developers of the Minux operating system only have Tan Ningbong professor, because the scholar is very busy Ah! Plus Tan Ningbong always think Minix is mainly used for educational purposes above, so for Minix is donuts! Yes, Minix is very popular, however, the voice of the user's requirements/needs may not be able to rise to a higher place! You know that, don't you? ^_^.

* 1984 Year Two: the GNU Project and the FSF Foundation

The GNU project, launched by Richard Mathew Stallman (Storman) in 1984, is an indelible place for today's free software craze! At present, we use a lot of free software, almost all directly or indirectly to help the GNU program! So who is Storman? Why would he launch the GNU project?

* A shared environment:

Richard Mathew Stallman (born in 1953, who claims to be RMS on the Internet) was very smart from a young age! When he was in 1971, he went into a well-known artificial Intelligence Lab (AI Lab) in the hacker circle, a time when hackers were referring to people with strong computer skills rather than destroying computers (cracker).

The hacker circle at that time was almost "sharing" the eye point of the software, so there was no patent problem! This feature has a great impact on Storman! Later, however, due to management problems, the lab's excellent hackers left the lab and went to other commercial companies to continue to develop excellent software. But Storman not concede defeat, still continue in the original laboratory to develop new programs and software. Later, he found that he alone can not complete all the work, so want to set up an open community to work together!

* Using the UNIX development phase:

After 1983, because of the replacement of the laboratory hardware, so that Storman can not continue to use the original hardware and operating system to continue to write free program ~ and he further found that in the past, he used the Lisp operating system, is the MIT patent software, is not shared, This is a hindrance to the desire to set up an open community of Storman. So he gave up the Lisp system. Later, he came into contact with the Unix system and found that UNIX could be ported between different machines in theory and in practice. So he started using UNIX systems instead.

Because Lisp and Unix are different systems, the software that he has already written is not able to run on Unix! To do this, he began porting software to UNIX. And, in order for the software to work on different platforms, Storman the software he developed into a portable form! That is, he will publish the original code of the program!

* Promotion of the GNU Project:

In 1984, Storman began the GNU Project, which was intended to create a free, open UNIX operating system. But it's not easy to build an operating system! And at that time, the GNU is only a single person to fight the Storman ~ This is too troublesome, but can not do this project, so Storman and line ~ ' Since the operating system is too complex, I first write can be run on Unix applet, this always OK? Oh! In this idea, Storman began to write the program. In the writing period, in order not to let oneself eat the lawsuit, he absolutely does not look at the patent software original code! For the purpose of the project, he began using software that was run on Unix, and wrote software that was similar to UNIX's original proprietary software.

But no matter what the software, it had to be compiled into a binary file (binary file) to be able to execute, so he began to write the C compiler, that is now quite famous GNU C Compiler (GCC)! This point is quite important! This is because the C language compiler version of a large number, but are patent software, if he wrote the C compiler is good enough to work well, then will greatly let the GNU project appear in front of everyone!

Tips: Computers only know 0/1 of the data, but people do not know Ah! Humans have a feeling for plain text data (the so-called ASCII file format). But the computer does not know the ASCII format of the text, very headache, is not it? Then there is the so-called ' compiler ' to assist us.

We generally use the text editor to write the program in ASCII plain text format, and then through the so-called ' compiler (compiler) ' to the newly completed text file ' compiled ' into a computer-recognized binary system (binary file) file, so that the computer knows and can execute the program Ah!

But it didn't go well at first, so he turned to the Emacs editor as a software that could run on UNIX and publicly publish the original code. Emacs is a program editor that can test the programmer's grammar as the user writes the program, which reduces the programmer's time for debugging! Because Emacs is so good, many people buy it directly from him.

The internet was not yet popular, so Storman was sold by Emacs on tape (tape), earning a little money and starting to write other software in full. And to set up the Free Software Foundation (FSF, Software Foundation), ask more engineers and volunteers to write software. Finally, the GCC has been completed, which is more helpful than Emacs! In addition, he also writes a number of C function libraries that can be called (GNU C library), as well as basic interfaces that can be used to operate the operating system bash shell! It's all done in about 1990 years!

Tips: If you use a text editor purely to edit a program, then the program syntax, if written incorrectly, can only be modified by the error message that occurs at compile time, which is really inefficient. Emacs is a great editor! Attention! Edit (editor) rather than compile (compiler)! He can quickly show that the syntax you write may be wrong, which is a good tool for programmers to do! That's why it's so popular!

* GNU General Public License:

By the year 1985, in order to avoid the free software developed by the GNU being used by others to become a patent software, he and his lawyer drafted a well-known common public License (License, GPL), and called him copyleft ( Copyright! with respect to proprietary software )。 There are several important software developed by GNU, such as:

* Emacs


* GNU C Library (glibc)

* Bash Shell

The result is that many of the software developers will be able to develop programs with these basic tools! Further expansion of the free software community! This is very important! However, for GNU's original idea of ' building a free Unix operating system ', these excellent programs are still not satisfied because there is no ' free Unix core ' present at the moment ... So these software can still only work on the patented UNIX platform ~ ~ Until the advent of Linux ... More FSF-developed software can refer to the following Web pages:


* 1988: Graphics Interface XFree86 Program

Given the growing demand for graphical user interfaces (graphical User Interface, GUI), the X Window System was first published by MIT and other partners in 1984, And in 1988, the non-profit XFREE86 group was established. The so-called XFREE86 is actually the integration name of X Window System + Free + x86! And this XFree86 GUI interface is more in the Linux Core 1.0 release in 1994, when the integration of Linux operating system!

Tips: Why is the graphical user interface X? Because by the English word, the W of window is x! It means the next version of window is! Be aware that X window is not x windows!

* 1991: A newsletter from Finnish university students Linus Torvalds

By the year 1991, Linus Torvalds of the University of Helsinki in Finland posted a message on the BBS that he wrote a small core program with tools such as bash, GCC, and the core program that works on Intel's 386 machines, which makes a lot of people interested! From now on, Linux is an extraordinary journey!

Unix operating system is a powerful multi-user, multi-tasking operating system, support a variety of processor architectures, according to the classification of the operating system, belongs to the time-sharing operating system, the earliest by Kenthompson, Dennis Ritchie and Douglas McIlroy in 1969
Developed at T-Bell Labs. At present, its trademark rights are owned by the International Open Standards Organization, only UNIX systems that conform to the single UNIX specification can use the UNIX name, otherwise it can only be called Unix-like (unix-like).
GNU is the father of free software, Richard Stallman, which was developed in 1984 as a software system based entirely on free software, with a corresponding generic public license (general publicly License, the GPL). Linux as well as with his
-Richard Stallman, like a stately missionary, is spreading the gospel of free software everywhere, explaining his dream of creating GNU: "The idea of freedom, not the free lunch". The "top priest" of the Free software
For his dream to pay for most of his efforts, he not only created a lot of free software, such as: GCC, and GDB, in his advocacy, at present people familiar with some software such as Bind, Perl, Apache, tcp/IP, etc. have become the classic of free software. If Richard Stallman founded and facilitated the development of free software, Linus Torvalds to GNU Linux without hesitation, bringing the development of free software into a new realm.
386BSD because legal issues were not released until 1992, NetBSD and FreeBSD were descendants of 386BSD, earlier than Linux. Linus Torvalds said that at the time, if there was a free 386-based unix-like operating system, he might not create
Linux. Although it is not possible to predict what effect this will have on the future software industry (if there is no such legal dispute, there is probably no revolutionary Linux today), one thing is certain that Linux enriches the soil.
Minix is a UNIX-like computer operating system based on micro-kernel architecture, invented by Andrew S. Tanenbaum. Minix was originally released in 1987, opening all the source code to university teaching and research work. Changed to BSD licensing in 2000 to become a self-
By and open source software. Sinceat7 Unix was launched, new terms of use were released, the UNIX source code was privatized, and Unix source code was no longer available in universities. In order to be able to teach in class the practical details of the operation of the student operating system, the Professor decides
Develop a UNIX-compatible operating system to avoid copyright disputes without using any of the source code. He referred to it as Minix, with the meaning of small Unix (mini-Unix). Minix no code to copy UNIX, so they do not have any inheritance relationship, Minix as the first open source operating system in the history of the internet after the short-term has been rapid development, a large number of people to download learning. Since Minix is written by one of the professors, there are some loopholes. At this time, there are users found that the vulnerability exists, want to download some patches or write some patches to fix these vulnerabilities, after patching found that the effect is good, and then suggested that the professor use these patches to finish
Good under the Minix, the result, the professor is more stubborn, meaning: In order to maintain the purity of minix, no foreign code is required. In other words, it is not intended to do commercial distribution, so Minux maintained its most primitive demeanor.
In the next few years, because of the strong operation of the computer hardware industry, the Intel-led x86 system architecture of the personal computer, so the personal computer is quite a popular machine. But at this point, most of the people use DOS operating systems.
At this time, a student named Linus Torvalds at the University of Helsinki in Finland did something unusual. He happened to have a 386 computer, because he did not like the DOS system on his computer, so he thought: since Minix so good, so stable, it
Why don't I transplant it to a personal computer (fortunately, because of the open source concept advocated by Stallman, he has access to some source Code, and through such an idea, O (∩_∩) o~ He is very interested in reading the UNIX core, and remove the more
1 . 0 release,
and cause the current pandemic ... Because of the development of Linux kernel by the virtual team, we are all through the network to obtain the core of Linux kernel source code, through their own careful transformation and then back to the Linux community, and then the development of a step-by-step completion
Linux system, and Linus Torvalds is the initiator of this group. Thanks to this collective effort, Linus Torvalds Linux as the GNU licensing model for the same benefit! Linux is Linus Torvalds influenced by Minix. But in the design philosophy, Linux and Minix big phase of the court. Minix uses the principle of microkernel in kernel design, but Linux is the same as the original UNIX with the concept of macro kernel
。 At the beginning of the development of Linux, the two sides also had a wonderful idea debate on the news group in 1992. Minix's authors and supporters argue that Linux's single-core architecture is "a big setback to the 70 's", while Linux advocates argue that Minix itself is not practical
Key Features
    • Basic ideas

The basic idea of Linux is two points:

1. Everything is a document. 2. Each software has a definite purpose.

The first article in detail is that everything in the system boils down to a file, including: commands, hardware and software devices, operating systems, processes, and so on, which are considered to have their own attributes or types of files for the operating system kernel. Linux is Unix-based, largely because of the similarity between the two basic ideas.

    • Completely free
Linux is a free operating system, users can be obtained through the network or other channels for free, and can arbitrarily modify their source code. This is not what other operating systems can do. It is for this reason that countless programmers from around the world are involved in the modification of Linux,
By writing, programmers can change them according to their own interests and inspirations, which allows Linux to absorb the essence of countless programmers and grow.
    • Fully compatible with the POSIX1.0 standard
This makes it possible to run common DOS and Windows programs under Linux with the appropriate simulator, which lays the groundwork for users to go from Windows to Linux. When considering Linux, many users think about whether programs that were common under Windows
To work properly, which eliminates their doubts.
    • Multi-user, multi-tasking
Linux supports multiple users, each user has their own special rights to the file device, to ensure that the user does not affect each other. Multitasking is one of the most important features of computers now, and Linux allows multiple programs to run simultaneously and independently.
    • A good interface
Linux also has a character interface and graphical interface, in the character interface users can enter the corresponding instructions through the keyboard to operate. It also provides a x-window system similar to the Windows graphical interface that allows users to manipulate it using the mouse. In
The X-window environment is similar to that in Windows, which can be said to be a Linux version of Windows.
    • Supports multiple platforms
Linux can run on a variety of hardware platforms, such as those with x86,0x0, SPARC, and Alpha processors. In addition, Linux is an embedded operating system that can run on a handheld, set-top box, or game console. Released in January 2001
2. The 4 kernel has been able to fully support the Intel 64-bit chip architecture, while Linux also supports multi-processor technology. Multiple processors work at the same time, which greatly improves system performance.
Linux version and virtualization introduction of Linux kernel version

The Linux kernel uses three different version numbering methods.

    1. Used before version 1.0 (including 1.0). The first version is 0.01, followed by 0.02, 0.03, 0.10, 0.11, 0.12, 0.95, 0.96, 0.97, 0.98, 0.99, and after 1.0.

    2. Used after 1.0 to 2.6, the number consists of three parts "A.B.C", A represents the major version number, B represents the minor major version number, and C represents the minor last version number. A only changes when the kernel has changed greatly (only two times in history, 2.0 in 1994, 1.0, 1996). The number B can be used to determine whether Linux is stable, even b for the stable version, and the odd B for the development version. C represents some bug fixes, security updates, new features, and number of drives.

      In version 2.4.0, for example, 2 represents the major version number, 4 represents the minor version number, and 0 represents a minor change in the last version number. In the version number, the second digit of the ordinal is an even version that indicates that this is a stable version that can be used, such as 2.2.5, and the second odd version of the ordinal is usually something new to join, which is not necessarily a stable test version, such as 2.3.1. This stable version is derived from the previous beta upgrade version number, and a stable version is not developed until it is fully mature.

    3. Starting with the 2004 2.6.0 version, use a "time-based" approach. Prior to version 3.0, it was a "a.b.c.d" format. Over the years, the first two digits a.b "2.6" remain the same, and C increases with the release of the new version, and D represents some bug fixes, security updates, additions to new features, and the number of drivers. After version 3.0 is the "A.B.C" format, B increases with the release of the new version, and C represents some bug fixes, security updates, new features, and drivers.

      The third way no longer uses even numbers for stable version, odd for the development version of the naming method. For example: 3.7.0 is not a development version, but a stable version!

Linux distributions

Linux is primarily used as part of a Linux distribution (often referred to as "distro"). These distributions are written by individuals, loosely organized teams, as well as business organizations and volunteer organizations. They typically include other system software and application software, as well as an installation tool to simplify initial installation of the system, and an integration manager that allows software to be installed and upgraded. Most systems also include programs such as XFREE86, which provide a GUI interface, that once ran in BSD. A typical Linux distribution includes: The Linux kernel, some GNU libraries and tools, a command-line shell, an X Window System for graphical interfaces, and a corresponding desktop environment, such as KDE or GNOME, and contains thousands of types of office suites, compilers, Text editor to the application software of scientific tools.

Because of the growing number of Linux companies, such as the famous red Hat, OpenLinux, Mandrake, Debian, SuSE and so on. So a lot of people are worried, so is every distribution (installation kit) different? This does not need to worry, because each distribution is architecture in the Linux kernel down the development of their own company style distribution, so everyone adhere to the Linux standard Base (LSB specification, that is, Each distribution in fact is similar, the use of all is the Linux Kernel, but each distribution inside the use of each package may not be identical only).

Linux Kernel official website:

Virtualization of

Partition planning VMware install Linux install Linux initial experience SSHSECURECRT and basic commands

Linux Primary knowledge

Related Article

Contact Us

The content source of this page is from Internet, which doesn't represent Alibaba Cloud's opinion; products and services mentioned on that page don't have any relationship with Alibaba Cloud. If the content of the page makes you feel confusing, please write us an email, we will handle the problem within 5 days after receiving your email.

If you find any instances of plagiarism from the community, please send an email to: and provide relevant evidence. A staff member will contact you within 5 working days.

A Free Trial That Lets You Build Big!

Start building with 50+ products and up to 12 months usage for Elastic Compute Service

  • Sales Support

    1 on 1 presale consultation

  • After-Sales Support

    24/7 Technical Support 6 Free Tickets per Quarter Faster Response

  • Alibaba Cloud offers highly flexible support services tailored to meet your exact needs.