Lect1.pdf

Introduction to linux Chpater1 1 The operating system: O.S An orchestra conductor 2 Definition «Formal » Definition: An Operating System (O.S.) is a machine abstract designed to facilitate the operation of hardware (device drivers)...

Introduction to linux Chpater1 1 The operating system: O.S An orchestra conductor 2 Definition «Formal » Definition: An Operating System (O.S.) is a machine abstract designed to facilitate the operation of hardware (device drivers) or to arbitrate access to hardware by users. O.S Generally composed of a kernel and a set of system tools, the OS makes it possible to develop portable applications, which are not specific to a given computer or system. 3 Definition “practical” ⚫ Set of programs necessary for the operation of the computer, independent of application programs but essential for their implementation. ⚫ Loaded into main memory at startup ⚫ Functions ❖ Resource management (memory, etc.) ❖ Input-output management ❖ File management ❖ Program management ❖ Ensure interface with the user 4  Linux History ⚫ 1969: creation of Unix - Ken Tompson (Bell Laboratories) ⚫ 1970: adaptation to DEC PDP-11/20 by Thompson&Ritchie and birth of the first portable language: the C language ⚫ 1974-77: Unix sources are distributed free of charge to Universities ⚫ 1978: Unix becomes the property of ATT and the sources become paying ⚫ 1979: creation of BSD Unix for the University of California at Berkeley ⚫ 1987: distribution of X Window, graphical interface for Unix developed by MIT 5  Linux History ⚫ 1987: AIX from IBM and HP-UX from HP are born ⚫ 1991: emergence of Linux ⚫ 1992: development of Sun OS by Sun ⚫ Linux was written by Linus Torvalds, a young student from Finland, and has been improved by many developers around the world. ⚫ 1991: Linux 0.1 and distribution of the source code on the Internet ⚫ 1993: Linux 0.99 ⚫ 1994: FreeBSD 1.0 based on BSD Unix ⚫ 1995: first “commercial” RedHat distribution 6 Introduction ⚫ The origins ⚫ Originally Linux is a UNIX kernel created in 1991 as part of a project initiated and coordinated by Linus TORVALDS. ⚫ Subsequently Linux designated the distributions built around this kernel. ⚫ Some distros Red Hat Mandrake Suse (Novel) Debian 7 Introduction ⚫Linux uses Unix functionalities without using proprietary code (remember, for example, that Unix System V is the property of AT&T). ⚫The development of Linux was done with "the same philosophy" as the GNU project 8  Introduction ⚫The FSF (Free Software Foundation) was founded in the early 1980s by Richard M. Stallman, a researcher at the MIT Artificial Intelligence laboratory. The goal of this foundation is to develop free software. ⚫The GNU project is an FSF project whose goal is to develop a complete operating system, distributed under the conditions of the GPL. ⚫The GPL (General Public License) is a license that specifies the conditions of distribution of all GNU software. ⚫The operating system developed by the GNU project is called HURD. 9  Free software ⚫ Free Software (according to http://www.gnu.org)? ⚫ The expression “Free Software” refers to freedom and not to price ⚫ The freedom to execute the program, for all uses (freedom 0). ⚫ The freedom to study how the program works, and to adapt it to your needs (freedom 1). For this, access to the source code is a required condition. ⚫ The freedom to redistribute copies, therefore to help your neighbor, (freedom 2). ⚫ The freedom to improve the program and publish your improvements, to benefit the entire community (freedom 3). For this, access to the source code is a required condition. 10 Free software ⚫A program is free software if users have all these freedoms. Thus, you are free to redistribute copies, with or without modification, free of charge or not. ⚫The only condition is that the sources of this software must be available free of charge to anyone who requests it. ⚫Linux has therefore been developed under the terms of a GPL license. 11 Richard Stallman. «I believe the Golden Rule is that if I like a program, I should share it with others who like that program. Software companies seek to divide and conquer users, prohibiting anyone from sharing with others. I refuse to break solidarity with other users in this way” General Public License 12 GNU Manifesto ⚫Free operating system launched in 1983 ⚫The basic idea of free software (Applications) is simple. ⚫When it is possible to have the source of an application ⚫Being able to modify and redistribute it, the application continues to evolve ⚫Everyone has the possibility to adapt it to their own needs. ⚫To correct programming errors ⚫And this evolution is happening at an astonishing speed. 13 Linux et GNU Linus Torvalds Decides to create an operating system that takes full advantage of the features of his new personal computer, a PC compatible Thus was born the Linux kernel. 14 Linux and GNU ⚫Richard Stallman wrote a lot of software ⚫he failed to create a complete, self- contained system. ⚫Only peripheral utilities were available in GNU. ⚫Torvalds notes the utilities for his system were already available in the form of GNU utilities and other free software. ⚫He integrated them all and baptized this complete operating system Linux. 15  Linux and GNU Richard Stallman Linus Torvalds 1991 saw the birth of the Linux kernel, generally distributed with software from the GNU project, GNU/Linux hence Richard Stallman's insistence that the whole is called GNU/Linux. 16  Linux History ⚫ 1969: creation of Unix - Ken Tompson (Bell Laboratories) ⚫ 1970: adaptation to DEC PDP-11/20 by Thompson&Ritchie and birth of the first portable language: the C language ⚫ 1974-77: Unix sources are distributed free to Universities ⚫ 1978: Unix becomes the property of ATT and the sources become paying ⚫ 1979: creation of BSD Unix for the University of California at Berkeley ⚫ 1987: distribution of X Window, graphical interface for Unix developed by MIT 17  Linux History ⚫ 1987: AIX from IBM and HP-UX from HP are born ⚫ 1991: emergence of Linux ⚫ 1992: development of Sun OS by Sun ⚫ Linux was written by Linus Torvalds, a young student from Finland, and has been improved by many developers around the world. ⚫ 1991: Linux 0.1 and distribution of the source code on the Internet ⚫ 1993: Linux 0.99 ⚫ 1994: FreeBSD 1.0 based on BSD Unix ⚫ 1995: first “commercial” RedHat distribution 18 Characteristic ⚫ Free ! ! ! ⚫ Open source: source code available and modifiable (for developers...). ⚫ The tasks performed by the applications are well identified ⚫ (confidentiality, freedom). ⚫ Collaborative development mode ⚫ Fine process control stability ⚫ Has many free and very successful software. ❖ Internet Explorer --> Mozilla-Firefox, Konqueror,... ❖ Microsoft Word --> Openoffice Writer ❖ Microsoft Excel --> OpenOffice Calc ❖ Microsoft Powerpoint --> OpenOffice impress ❖ Notepad --> Kate, emacs, vi... ❖ Photoshop --> The Gimp ❖ Access --> Mysql, PhpMyAdmin... ❖ Windows media player --> kaffeine, xine, Mplayer... ❖ Audio software: Amarok, juk... ❖ Image visualization: digiKam, kuickshow... 19 Characteristic ⚫Linux + : ⚫ Secure system (almost non-existent virus, no spyware). ⚫ Built-in firewall. ⚫ Comprehensive documentation. ⚫ Linux-: ⚫ Device compatibility (Linux is shunned by some manufacturers). ⚫ Sometimes requires some settings afterwards ⚫ installation. ⚫ Computer skills required (??). 20 Characteristic ⚫ Multi-user / Multi-tasking ⚫ Multi-platform (portable) ⚫ Manages the distribution of resources (memory and disk space) ⚫ Network oriented (e.g. file sharing on a machine remote: NFS…) ⚫… ⚫ Widely used in development and research ⚫ very stable ⚫ Easy to use 21 Distributions ⚫ There is a very wide variety of distributions, each with different objectives and a particular philosophy. ⚫ The elements differentiating the distributions are: ⚫ user-friendliness (ease of implementation), ⚫ integration (size of the distributed validated software fleet), ⚫ notoriety (informative community to resolve issues problems), ⚫ the desktop environment (GNOME, KDE,...), ⚫ the type of package used to distribute software (mainly deb and RPM) and the maintainer of the distribution (usually a company or community). ⚫ The common point is the kernel and a certain number of commands. 22 Distributions ⚫ 1. Linux Mint ⚫ 2. Redhat ⚫ 3. Ubuntu ⚫ 4. Fedora ⚫ 5. OpenSUSE ⚫ 6. Debian ⚫ 7. Arch Linux ⚫ 8. CentOS ⚫ 9. KALI ⚫ 10. CentOS 23 2 4 Debian ⚫ Debian is still available in three versions (three branches) which are: ❖ stable: frozen version where the only updates are security patches; ❖ testing: future stable version where only sufficiently mature packages can be included; ❖ unstable: nicknamed Sid, this is a version in constant evolution, endlessly fed by new packages or updates of already existing packages (we speak of Rolling release). 25