Basics of Linux Basics (i)

a , the composition and function of computer

The basic structure of modern computers is made by the Hungarian-American scientist von · Neumann was introduced in 1946. So far, all the computers that have entered the utility are press von Neumann proposed structural system and working principle of design and manufacture of this is collectively referred to as "von Neumann-type computer".

According to the division of its function, the computer composition is divided into five parts:

1. Controller: The central nervous system of the whole computer, its important function is to analyze the control flow information stipulated in the program, control it according to its requirements, dispatch program, data, address, coordinate the access of memory and peripherals, etc.

2. Arithmetic (Datapath): The function of the operator is to perform various arithmetic and logical operations on the data.

3. Memory: Mainly used to store data, various signals and command information, and according to the requirements of the Controller to provide the appropriate information

4. input System: Mainly used for data, signal, program, command and other information input,

5. output system: It is mainly used to output the intermediate or final results of the computer and data symbols, text or control signals in the process of operation.

The interaction between its various parts can be expressed as:

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The specific equipment of these five parts in our actual application is shown below:

Cpu= operator + controller (Inter, AMD) memory = memory (temporary storage) + hard drive input device = keyboard, mouse, scanner, etc. output device = monitor, printer, etc.

Second, the distribution of Linux, the relationship between the distribution and the difference between

Today's popular Linux was first written by Linus Benedict Torvalds in 1991, also known as Gnu/linux. Because Linux is fully open source code, attracting many outstanding programmers and developers to join the GNU organization, the Linux kernel constantly modified and perfected, it makes today's gnu/linux blooming, blossoming spectacular scene. The distribution of Linux can be divided into two categories according to its mode of operation: One is the distribution version maintained by the commercial company, the more famous one is Redhat, Novell and so on, and the other is the distribution version maintained by the community organization, the more famous one is Debian, CentOS and so on gnu/ Linux has many distribution branches

Below we introduce several popular branches

1. Redhat Series

redhat Linux was released by a man named Marc Ewing in 1994 and was incorporated into Red Hat software company by ACC in 1995, a provider of open source solutions Provides mission-critical software and services for many important it technologies (operating systems, storage, middleware, virtualization, cloud computing), as well as technical support, training, and consulting services for customers around the world, with a corresponding fee. 2002 Red Hat Company launched the Linux Advanced Server Edition, that is, later Rhel,dell, IBM, HP, Oracle Company announced the support of the platform, March 2007, Red Hat Company released the most classic Redhat Enterprise Linux5 version, Successive launches of RHEL5.5 、...... RHEL6, up to now the latest RHEL7.2 version, is updated every five years or so, and has a great advantage in system stability, foresight and security. Get Red Hat's official technical support service by purchasing its serial number.

Fedora Linux is a personal, desktop Linux release based on Redhat Linux, sponsored by the Fedora Project community and Red Hat Corporation, with the goal of producing and publishing third-party software packages for Redhat Linux, Redhat After Linux stopped releasing, the Fedora community was integrated into Red Hat's Fedora Project, which became the experimental plot for Redhat new technology; Redhat will write some new technologies into Fedora, and the technology that is thought to be available will eventually be integrated into Redhat Enterprise Linux release, Fedora releases a new version approximately every 6 months, and the latest version is Fedora23

Centos (Community Enterprise Operating System: Community Business Operating system), is based on Redhat Enterprise Linux Open source code compiled, on this basis fixed a number of known bugs, completely free. Rhel has two modes of distribution:

1. Distributed in a binary way;

2. Published in source code mode;

CentOS is the open source operating system generated by recompiling its source code, so CentOS can get all the features of RHEL, even better software, as long as it is legal to not use the Redhat trademark. CentOS does not provide commercial support to users and does not have to take any commercial responsibility. CentOS is updated approximately every six months, and new versions are released every two years. The CentOS community was acquired by Red Hat in 2014 and CentOS continues to be free.

2. Debian series

Debian is an operating system comprised of free software licensed under the GPL and other free software licenses, and is maintained by the Debian Project organization. The Debian project is an independent, decentralized organization consisting of 3000 volunteers who receive financial support from a number of non-profit organizations around the world, software in the public interest to support and hold a trademark as a protection agency. Debian is a large system organization framework under which a number of branching programs of different operating system cores are available, mainly:

• < Span style= "FONT-SIZE:14PX;" >      uses the Linux core Debian Gnu/linux system

•       uses the GNU Hurd core Debian Gnu/hurd system

• P style= "margin-top:20px;margin-bottom:20px;" >      uses the FreeBSD core Debian Gnu/kfreebsd system

•        uses the NetBSD core Debian Gnu/netbsd system.

•        Nexenta OS system built with OpenSolaris core.

         in these Debian systems to use the Linux core Debian Gnu/linux is the most famous. Numerous Linux distributions, for example: Ubuntn, Knoppix

ubuntu is based on the Debian distribution and GNOME desktop environment, Ubuntu based on Debian's unstable branch, more close to the development concept of Debian, it mainly uses free, open source software. The difference with Debian is that it releases a new version every 6 months (that is, April and October each year) and releases an LTS long-term support version every 2 years. There are currently five long term support,lts versions of Ubuntu: Ubuntu 6.06, 8.04, 10.04, 12.04, and 14.04. Ubuntu 12.04 and 14.04 have 5-year support cycles for both desktop and server editions. And the previous long-term support version is desktop version 3, Server Edition 5 years. The use of the sudo directive for all system-related tasks in Ubuntu is a feature that is more secure than the traditional way of managing a system administrator's account, one of the basic thinking of Linux and Unix systems. Ubuntu plans to emphasize ease of use and internationalization, in the release of the 5.04 version, the Universal code (UTF-8 Unicode) as the system default code, in order to respond to different countries in various regions of the language text, trying to provide users with a non-garbled communication platform. is one of the best choice for Linux beginners. Its derivative versions are numerous.

Knoppix based on Debian Gnu/linux, the desktop system mainly uses KDE, the main software also includes GIMP, LibreOffice and so on. A CD-ROM or USBU disk-initiated Gnu/linux system (LiveCD), features include automatic hardware monitoring, support for common graphics cards, sound cards, SCSI and USB devices, and other peripherals. Knoppix can be used for Linux demonstrations, CD-ROM teaching, System first aid, properly modified, and can also be used for product demonstrations of commercial software. Its advantage is that Knoppix hardware support is excellent, even the newer products, many can be used normally. The disadvantage is that the support of the environment in Japan and South Korea is very poor, in the system pre-built Chinese character font file, typos, short words, font proportion is also disproportionate.

3.Slackwarex

slackware is a Linux distribution made by Slackware Linux, Inc. 's Patrick Volkerding. Slackware took a different path from other distributions (Red Hat, Debian, Gentoo, SuSE, Mandriva, Ubuntu, etc.) and tried to become a "UNIX-style" Linux distribution. Slackware is mainly for x86 PC development, Slackware 13.0, the official first to provide 64-bit version download.

suse Linux was originally based on Slackware Linux and provided a complete German interface for the use of the product. SuSE was founded at the end of 1992 and specializes in the introduction of tailor-made sls/slackware software and unix/linux documentation for Germans. "S.U.S.E." Later renamed/abbreviated as "SuSE", German meaning "Software-und System-entwicklung", English as "Software and System development". SUSE Linux uses many of the features of Red Hat Linux (using RPM and/etc/sysconfig). SuSE contains an installation and System Management tool, YaST2. It is capable of disk partitioning, system installation, online updating, network and firewall configuration settings, user management, and much more. It provides a convenient combination interface for the original complex setup work. In January 2014, Novell acquired SuSE. Its commercial version is SUSE Linux Enterprise Server, the latest version is SUSE Linux Enterprise

OpenSUSE, formerly known as SuSE Linux and SuSE Linux Professional, is a Linux distribution and project sponsored by SUSE and other companies. Is the release version created by Novell after acquiring SuSE Linux. Its focus is on creating the applicable open source tools for software developers and system managers, as well as providing an easy-to-use desktop environment and a feature-rich server environment. openSUSE is a series of optimizations for desktop environments that are more friendly to Linux novices.

Third, the philosophical thought of Linux

1. All documents: The abstraction of almost all resources in the form of documents including communication interfaces, hardware devices are also represented by documents, which facilitates unified management and definition.

2. Consists of a number of functions of a single program, a program to do one thing, and do a good job, the combination of small programs to complete complex tasks, so as to ensure the efficient operation of the Linux kernel.

3. Try to avoid interaction with users, easy to implement automation tasks programmatically, can be scripted to achieve a large number of server automation operations.

4. Using a text file to save configuration information, all Linux configuration files are stored in the text configuration file (example:/etc/files), no matter what configuration changes are only necessary to modify its configuration file, the configuration file when the text form of any text editor can only be modified.

This article is from the "Wang Liming" blog, make sure to keep this source http://afterdawn.blog.51cto.com/7503144/1853604

Basics of Linux Basics (i)