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Chapter An Introduction to Linux What is Linux • One of the fastest growing operating system today • Unix-like operating system • Named after Linus Torvalds (creator) – Linus + Unix = Linux • Powerful – Speed and reliability – Runs on many different types of hardware • For most part it is free or so far inexpensive compared to Microsoft What is so special about Linux. Linux is said to be: Reliable. Simple. Free! Runs on a variety of platforms. considered the most important free software achievement. Able to turn any 80386 or better PC into a workstation. What’s With The Penguins? • Linus Torvalds is a naturalists and he always liked penguins Unix-Linux Origin Unix Originally developed at AT&T as a multitasking system for minicomputers and mainframes in the 1970’s. Linux Developed primarily be Linus Torval. Inspired by Minix. Kernel uses no code from AT&T or any other proprietary source. Developed by a group of volunteers, primarily in the Internet, who exchange code, report bugs and fix problems. Linux History • First posted on the Internet: in October 1991 • Linux 1.0 was released in 1994 and Linux 2.2 in 1999 • Today Linux runs on millions of computers with thousands of programmers improving it continuously and sharing the code with others The GNU Project Launched in 1984 to develop a completely Free Unixlike operating system: The GNU System. Many flavors of the GNU system are currently in use, i.e. Caldera, Redhat, Corel, etc. These GNU Systems use the Linux Kernel, these systems are incorrectly called "Linux", they should be called GNU/Linux systems. GNU is "Copylefted". Copyleft uses copyright law in reverse. It allows software to be used, modified, and distribute modified versions. Modified versions may not add restrictions of their own. Visit www.gnu.org for more information. What is so special about Linux. Linux is said to be: Reliable. Simple. Free! Runs on a variety of platforms. considered the most important free software achievement. Able to turn any 80386 or better PC into a workstation. Linux Strengths • Powerful • Networking and e-business capabilities – associated with Apache Web Server • Reliable • Free to download – or affordable through distribution CDs Linux Reservations • Linux is still primarily a network operating system intended for servers – There are versions intended for clients now being released • Linux is not as user friendly compared to Microsoft operating systems • Users must learn commands to harness the full benefits of Linux LINUX Features: Complete multitasking, multiuser OS. Compatible with Unix standards. Supports virtual consoles. Supports various file systems for storing data. Provides complete implementation of TCP/IP networking software. Include device drivers for many Ethernet cards. LINUX Features (cont.) Kernel is developed to use protected-mode features of Intel 80386 and better processors. supports demand-paged and loaded executables. supports copy-on-write pages. Linux can coexist with other OS on the same machine. Typical Uses of Linux • Server – Web servers and firewall – Dedicated Print servers and File servers – Used as an operating system on less powerful hardware • Desktop – Desktop versions are now being made available (Workstation edition of Red Hat) – Many desktop applications exist today – More are being quickly developed Linux Application Areas • Not only the enthusiasts • ISP (Internet service providers) • Engineering companies • Retail • Publishing • Financial • Healthcare • ……..and more Linux Based Network Linux Interface with the Hardware • Unix-like – Kernel: the part of the operation system that interacts with the hardware – Shell: the part of the operating system that interacts with the user User Shell Kernel Hardware Linux Implementations with User GUI GUI Shell Kernel Hardware GNU/Linux K Desktop Environment KDE is a powerful GUI desktop environment for Unix workstations. Provides ease of use, contemporary functionality, and the technological superiority of the Linux OS. KDE is an internet project that is "Open" in every sense. All KDE sources are open to everyone and may be distributed by anyone subject to the well know GNU licenses. KDE is a mature desktop suite. Visit WWW.KDE.ORG for further information. Current KDE Distribution Includes the following packages: KDE-Libs: Various Run-time libraries KDE-Base: The base components KDE Graphics: e.g. Kpaint, Kfax, Kghostview KDE Utilities: Kedit, KCalc, Knotes KDE-Multimedia: KMidi, Kmodplayer, Kmixer, KSCD KDE-Games: Kasteroids, Kpat, Ktetris KDE-Admin: Various rools to aid system administration Current KDE Distribution Includes the following packages: KDE-Network: Kppp, Krn, Kmail Most current distributions of Linux Use a modified version of KDE. Corel calls its version Enhanced KDE. Visit Linux.Corel.com, Linux.com, Linuxworld.com for more information. Demonstration. Linux Directory Structure (/) The Linux TCP/IP Networking Layers Network Application User Kernel BSD Sockets Socket Interface INET Sockets Protocol Layers UDP TCP IP Network Devices PPP SLIP ARP Ethernet Obtaining the Linux Operating System • By downloading from websites • Purchasing from a computer retail store • Obtaining sources from Linux related magazines Some Linux Vendors and their Websites • Caldera OpenLinux 2.3 – http://www.calderasystems.com/ • Corel – http://linux.corel.com • Mandrake – http://www.linux-mandrake.com/en/ • Red Hat – http://www.redhat.com – know for its package manager – Perhaps the most popular site Linux Related Websites • General Linux Websties – http://www.linux.org – http://metalab.unc.edu/mdw/index.html • Linux in business – http://www.linux-business.com – http://www.linuxresources.com • Linux Technical Websites – http://www.slashdot.org – http://www.linuxbase.com Module Linux Vs Windows Licensing and Code Ownership Manufacturer Windows 2000 Linux • open-source community • couple of vendors Microsoft Licensing Fee Linux Windows 2000 No Yes Installation Ease Linux Windows 2000 • getting easier • but still more than Windows 2000 because of the experience of previous versions, it’s very easy to install and setup automated software setup over a network User Interface Linux Windows 2000 • DOS-like command-line • Newer versions have GUI interfaces such as Gnome and KDE GUI-based Availability of Applications Linux Windows 2000 • few existing applications for Linux • more and more applications are written for running on Linux but not mainstream yet. (e.g. support by IBM) many applications are available Reliability Linux Windows 2000 • good • many users report that it can be run for months without crashing • Good • Reliability has improved over the years Anticipated Growth in Market Share Market Share for Server OS, 1998 vs. 1999 Future of Linux Reasons for growth • the undercurrent of dissent against Microsoft (i.e. as an alternative to the Windows O/S) • Competing vendors such as Sun promoting the Linux operating system • ability to modify the source code • control and freedom for the power user • easy to obtain Module Major Linux Features Office and Email Applications • Office Applications – Ex: StarOffice, Koffice, Applixware and Corel Wordperfect • Email Clients – Ex: kmail, spruce, netscape and mozilla Video and Audio • Graphic Editors & Manipulators – Ex: The GNU Image Manipulation Program(GIMP) • Audio, Video and DVD – – – – Video clips compact player-xanim Mpeg player-gtv, mtv DVD player-Livid MP3 player-mpg123 • Voice Recognition – Xvoice works on any X11 application – CvoiceControl is used on Linux console Internet Applications • Internet Browsers – Ex: Netscape • Internet Chat – Ex: Xchat • Web Page Editors – Ex: Amaya Network Protocols Supported • • • • • • TCP/IP IPv6 IPX/SPX AppleTalk Protocol Suite PPP, SLIP, PLIP Amateur Radio Internet Servers and Browsers for Linux • Mail Server – Sendmail • Web Servers – Apache • Web Browsers – Netscape Navigator Internet Services Supported • FTP Servers and clients • News Services • Domain Name System • DHCP • NIS • Authentication Remote Execution of Applications • Telnet • The X Windows System Security Issue • Web Server Attacks • Weak Passwords • Denial of Service Attacks • Man in the Middle Attack • IP Address Spoofing • Network Snooping • Impersonation Sample Web Servers for Linux • Apache server – Perhaps the most popular web server for Linux • NCSA HTTPd – http://hoohoo.ncsa.uiuc.edu • Netscape Fast Track Server • AOL server – http://www.aolserver.com/server • iPlanet Web Server • etc. Apache Server • Developed by NCSA in 1995 • Apache and its source code is free • Runs on Unix and Linux • Supports HTTP 1.1 Apache Strengths • High market share – Over 57% web sites are using Apache • Flexible • Available free of charge Apache Weakness • Performance – should create portable code for its OS • Fully guided GUI based installation is yet to materialize • Few application services Apache vs. IIS: A Quick Comparison Apache IIS SQL Database Interaction Perl, PHP ASP GUI Installation On developing Yes Cost Low High Management tools Poor Good Steady as load increased Good Poor Built search engine No Yes Flexibility High Low Market share High Lower than Apache Top Server Source : Netcraft web server survey Linux SQL Database (Free) • MySQL – a true multi-user, multi-threaded SQL database server – a client/server implementation • PostgreSQL – a sophisticated Object-Relational DBMS – Supports almost all SQL constructs • GadFly – a very small, fast and highly portable database system – support a large subset of ODBC 2.0 SQL MySQL Implementation Example PHP Apache script PHP MySQL Server Web page on browser Web Research • Visit the Red Hat and the Mandrake website at the following addresses to obtain additional information – www.redhat.com – http://www.linux-mandrake.com/en/ Module Linux Multimedia Audio Mixer and Sound Player AuMixer Console-mixer tool. http://jpj.net/~trevor/aumix.html B-play Sound player, pretty good. ftp://sunsite.unc.edu/pub/Linux/apps/sound/pla yers/ Synathesia You just can't live without this program! Is a 'visual' CD player. It's just a SVGAlib CD player that shows some nice effects while playing ftp://sunite.unc.edu/pub/Linux/apps/sound/light More on CD Players • WorkMan A VERY nice XView CD player. ftp://sunsite.unc.edu/pub/Linux/apps/sou nd/cdrom/X/ MOD Player and Sound Recording MikMOD Regular MOD player, plays most of the MOD-file types - in the way YOU wish. You can also get a XInterface http://www.tohs.abacom.com/mikmod/ MiXViews A full featured sound recording / editing program. Does everything and more. You have many effects and so on. I only find some disabilities: bugs (a few), no "dynamic" recording, not so many file formats, ugly GUI. http://www.ccmrc.ucsb.edu/~doug/htmls/MiXVie ws.html More on Sound Recorders X-Wave A sound recorder / player. Get it NOW at: ftp://sunsite.unc.edu/pub/Linux/apps/sound/edit ors/ Related: http://www.filefarm.com/filefarm/linux/subje cts/524/ http://eunuchs.org/linux/frames.html http://eunuchs.org/linux/scanner/index.html http://eunuchs.org/linux/ip_masq/index.html MPEG Mpeg 1 Layer 3 (mp3) Tools A mp3 encoder and a decoder, for making your own mp3 files / tweak with someone elses. Do I need to say anything more? And, ther's some other tools at the same homepage. http://www.mpeg3.org/main.html sPlay MPEG 3 Audio player. http://adam.kaist.ac.kr/~jw95/ Audio Editor • Multitrack Multitrack is a SVGAlib digital audio editor. It'll soon come out in a 2.0 version. It's too bad it's not X-based. Another irritating thing is that you must create the WAVE files that you are going to record before you can record. http://rulhmpc38.leiden.univ.nl/private/mu ltitrack/multitrack.html MIDI Rosegarden And now! That all of you been waiting for! A MIDI program that works! It have a notationing system and so on! Perfect! Nothing to complain about...yet! http://www.bath.ac.uk/~masjpf/rose.html Playmidi A general MIDI player. ftp://sunsite.unc.edu/pub/Linux/apps/sou nd/players/ Animation Player X-Anim A animation player for X, plays many, MANY formats. http://smurfland.cit.buffalo.edu/xanim/ho me.html MPEG Movie Player XView Mpeg A XView based mpeg movie player. /pub/Linux/apps/graphics/viewers/X/ End of Chapter THANK YOU