1, description of the structure and functions of the computer.
1）：CPU（运算器Arithmetical Unit和控制器Control Unit）运算控制器Operator Arithmetical Unit: central nervous entire computer, its function is the control information interpreted predetermined program, is controlled according to its requirements, access schedule program, data, addresses, each part of the work and the coordinating computer memory and peripherals Wait.
Controller Control Unit: arithmetic function is the data various arithmetic operations and logic operations, i.e., data processing
2）：存储器Memory：存储器的功能是存储程序、数据和各种信号、命令等信息，并在需要时提供这些信息
3）：输入Input：输入设备与输出设备合称为外部设备，简称外设，输入设备的作用是将程序、原始数据、文字、字符、控制命令或现场采集的数据等信息输入到计算机。常见的输入设备有键盘、鼠标器、光电输入机、磁带机、磁盘机、光盘机等
4）：输出设备Output：输出设备与输入设备同样是计算机的重要组成部分，它把计算机的中间结果或最后结果、机内的各种数据符号及文字或各种控制信号等信息输出出来。微机常用的输出设备有显示终端CRT、打印机、激光印字机、绘图仪及磁带、光盘机等。2, describes the core functions and the role of
1) kernel and the kernel into a single micro-kernel, Linux is a single core design, but draws on the advantages of micro-kernel design, the introduction of a modular system. The kernel is the lowest level of the entire operating system, which is responsible the entire hardware drivers, as well as provide you with any system core functions, including firewall mechanism, whether or Quota support LVM file system, etc., if the kernel does not recognize a new hardware, the hardware will not be able to be driven, you You will not be able to use the hardware.
1)内核的组成部分kernel:内核核心,一般为bzimage,通常位于/boot目录,名称为vmlinuz-VERSION-release
2)kernel object:内核对象,即内核模块,一般放置于/lib/modules/VERSION-release/ 内核模块与内核核心版本一定要严格匹配2) function of the kernel process management
进程的状态、控制、同步互斥、通信调度
存储管理 分配/回收、地址转换、存储保护等
文件管理 文件目录、文件操作、磁盘空间、文件存取控制
设备管理 设备驱动、分配回收、缓冲技术等
用户接口 系统命令、编程接口3, according to the series listed common Linux distributions and describe connections and differences between the different releases.
2) release and Differences Contact
Contact:
(1) All distributions use linux kernel;.
(2) All linux distributions need to follow the GNU GPL agreement. Or provide a good source or translation package (such as CentOS);
(3) all distributions has its own version, the version is basically the same format conventions. Major version. Minor version number. Issue or revision numbers
The difference between:
(1) only operate in the manner debain community.
(2). The essential difference release, is the integration of a combination of different versions of the kernel, libraries, the program.
Not valid comparison between versions (3) different publishers release.
(4) using different distributions almost different package manager (a) Debian:. Package manager dpkg (deb format), apt-get (b) RedHat:. Package Manager rpm, the front end of the package manager called yum DNF (new) (c) SUSE:. package Manager rpm, zypper (d) ArchLinux: .. package Manager port (e) Gentoo: mounting side, while compiling LFS: Linux From Scratch (f) .kali comprising more linux security tools
4 difference, describing common open source license (GPL, LGPL, BSD, Apache, etc.) as well as open source license
GPL
GPL grants program accepts people the following rights, or "freedom":
* Run this program free for any purpose
* The working mechanism of learning process for the purpose of the program is free to modify (to get the source code is a prerequisite)
* Re-issue free copies of
* Improved program and publish the improved free (can get the source code is a prerequisite)
On the contrary, with the end-user software license Copyright almost never granted to any user rights (except the right to use), and may even limit permitted by law behavior, such as reverse engineering.
GPL compared to some other more "licensed" free software licenses (such as BSD license), the main difference is that the GPL seeks to ensure that these freedoms can be protected in the copies and adaptations of the works. It's called copyleft legal mechanism by means of a realization of the invention by Stallman, which requires derivative works of GPL program should be under GPL. In contrast, BSD-style license does not prohibit derivative works become Copyright software.
GPL license does not grant the right to unlimited recipients. Re-distribution rights granted to licensees who need to open software source code, and any modifications. And a copy of the modified version, must be based on GPL as a license.
The requirement is copyleft, its foundation is in the works Copyright law. Because it Copyright licensee has no right to modify and re-release (except fair use), unless it has a copyleft provisions. If someone wants to exercise their rights are generally prohibited by law, just agree to the terms of the GPL. Conversely, if someone issued software in violation of the GPL (such as not open source), he may be sued original author.
copyleft use copyright law to achieve the opposite purpose: copyleft gives inalienable right, not many restrictions under copyright law. This is also the reason GPL is called "the black copyright law".
Many software publishers regard the GPL source code and executable programs bundled together. Another way is to physical media (such as CD) to provide the source code for the carrier. In practice, many of GPL software is distributed on the Internet, the source code can also get a lot of FTP.
copyleft effect occurs only when the program is re-issued. Modifications to the software can not open or open source, it does not release. Note copyleft only the effectiveness of the software, and the software output of no effect (unless the output is the software itself). However, this is subject to change in GPL version 3.
MPL
The Mozilla Public License MPL is shorthand for a software license in early 1998 Netscape's Mozilla open source software project team for its design. The most important reason is the emergence of MPL license, Netscape Company believes that the GPL is not a good balance between the interests of developers the source code and the need for them to use the source code available. Compared with the well-known GPL license and BSD licenses, MPL in many aspects of the agreed rights and obligations and they are the same (since they are in line with the open source software licenses OSIA identified). However, compared to MPL there are several notable differences:
* MPL Although modifications to the requirements issued by the MPL license the source code should be a way out sublicense MPL licenses, to ensure that others can share the source code under the terms of the MPL. However, MPL license in the definition of "publication" is "as source code released documents", which means that MPL allows a business plus an interface on their existing source code library, in addition to the source interface program Code-licensing in the form of MPL license, the source code library source code compulsory license out the way you can not MPL license. These, to learn from others on the behavior of the source code used in its own commercial software development left a gap
* Paragraph 7 of Article 3 MPL license allows source code licensees will MPL license obtained through other types of code with their own mix to get their own software program.
* Attitude toward software patents, MPL licenses like the GPL license as clearly expressed their opposition software patents, but it clearly requires the provider does not provide the source code of the source code has been subject to patent protection (unless he himself is the patentee, and written free license source code to the public), nor in the source code license to open-source license application form and then go to the source code and related patents.
* Definition of the source code
In MPL (1.1 version) license, the definition of the source code is: "refers to the source code form of the work for making modifications choose to take top priority, which includes: all the source code for all modules, plus any associated interface definition, plus control and installation of the executable compiled 'original' (description of 'Script'), or is not significantly different from the original source code and the source code is to be contributors to the source code in the public domain may be selected to give the code."
* MPL license to Rule 3 is a special provision on the source code modification described, it is requiring all publishers then had to have a special file to have a description of the procedures to modify the source code and modify the way of time .
LGPL
GNU General Public License, referred to as the LGPL (GNU Lesser General Public License), are used in some (but not all) GNU libraries. This license was formerly called the GNU Library (Library) General Public License.
GPL LGPL is a variant of GNU is to get more support and even commercial software developers proposed. The biggest difference is that with the GPL, can use the free software proprietary LGPL licensed, developed new software can be private without the need to be free software. So before any company should ensure that the use of free software under license GPL LGPL or other variants.
Apache License
Apache License agreements are well-known non-profit organization open source Apache used. The agreement is similar to BSD and also encourage code sharing and respect the original author copyright, also allows code changes, then released (as open source or commercial software). Conditions need to be met:
* Users need to code a Apache License
* If you modify the code, you need to be modified file description
* Extending in the code (and code modification of source code derived) needs to have the original description code protocol, trademarks, patents, and other statements contained in the original OF predetermined required
* If the re-released product contains a Notice document, the document required in the Notice with the Apache License. You can add your own license in the Notice, but not the performance for the Apache License constitution change
Apache License is licensed for commercial use friendly. Users can also modify the code as needed to meet the needs and as open source or commercial product launches / sales.
BSD
License, BSD (FreeBSD Copyright Information) with a variety of authorized licenses. In general you can deal with any of the software, as long as you indicate in its software from the project on it. That means you have more freedom to dispose of the software. If you made changes to the software, you can limit other users freedom to modify your software.
BSD License, did not achieve the "permeability" of freedom, that is, it does not guarantee that the software is open source code continuity. So if you wish to use BSD software developed by others, make some changes, and then as a product to sell, or just some of their secret work done in addition to software development, then you can benefit from.
When a non-programmers only understand the function of a program, but do not understand how the program is doing, even if you do not have to do any work in the development of software that you can market through the superb skills will sell the software to the user. Take for example the most popular desktop operating system as an example, you can not have a good understanding of a good software skills program as long as the company has a superb marketing strategy to sell customers the same garbage can. If you do not have a very powerful programming capabilities, but has a strong ability to market and other software developers can include into their system, while at the same time not to open up their own modifications will be very powerful capability. For the purpose of making money from a business point of view, if you use a software license BSD license, then you can be arbitrary. You can better control your OS system and prevent other people copy your commercial product.
WITH
MIT and BSD is as broad as the license agreement, the authors want to retain the copyright, without any other restrictions. In other words, you must include a statement of the original license agreement in your distro, no matter you are in binary or released in source code released.
There are many groups are using MIT License. Such as the famous software PuTTY ssh connection with X Windows System (X11) is the example. Expat, Mono development platform library, Ruby on Rails, Lua 5.0 onwards and so on are also using MIT license terms.
5, description of the Linux philosophy, and according to their own understanding of its explanatory description.
1) everything is a file
to almost all the resources all abstract as a file: include hardware devices, communication interface settings
file operations: open (), read () , write (), close (), delete (), create ()
2) by a total of a single multifunctional programs: a program to do one thing and do a good job; a combination of a small program to complete complex tasks
3) Try to avoid interaction with the user:
Goal: easy to programmatically automate tasks
4) Using a text file to save the configuration information
6, description linux directory structure directory structure and naming conventions.
The directory structure: inverted tree
Use the file name rule:
Strictly case-sensitive: file1, File1, FILE1
It is the file directory, in the same path, two files with the same name can not
Support the use of any character other than /
It can not be longer than 255 characters