Introduction to Linux Chapter 1

Operating Systems Operating System (OS) - most basic and important software on a computer Performs core tasks Organize files Manage input and output Manage hardware Manage other software (applications) Manage users Handle security Perform regular maintenance of system

Operating Systems (contd.) Various kinds of OS Multi-user Multitasking Real time etc. Examples of OS Unix DOS Windows NT/98/2000/XP/ Vista Mac OS X Linux!

Key Linux Features Based on Unix Usually free download Command line based; CLI-centric vs GUI-centric Secure, can be made custom secure by user Numerous free tools and applications Installation of apps may be difficult for a novice Very customizable Whole ‘kernel’ can be updated Fast development

Origins of Linux Based on Unix Project started by Linus Torvalds in 1991 Idea: Replace Minix as the ‘hacker’s Unix’ First version, 0.02, released Oct. ‘91 : very unsuable Major version, 1.0 released March ‘94 Linus still maintains the Linux ‘kernel’ Best example of Open Source software Kernel in constant development Version numbering of kernel even (2.0, 2.4) for stable kernel odd (1.7, 2. 3) for development kernel

The GNU Connection GNU (GNU is Not Unix) tools are in every Linux distribution Provided by the Free Software Foundation (FSF), founded by Richard Stallman Advocates freedom of software Ideas present in GNU General Public License (GPL) Call Linux - GNU/Linux

Open Source Phenomenon Proprietary vs. Open source Free as in price and as in ‘freedom’ Copy Modify Sell Can view, alter, and re-publish original software’s internals Released under GPL license usually BSD license Apache license Developed by a loose community of volunteer hackers Various open source software for different OS

Linux vs. Windows Free and Open Source More secure (?) Less hardware support (much better now) More customizable Much more powerful command line interface Less mature GUI Fewer applications and games Hackable!

Linux vs. Unix Linux - free equivalent of UNIX Much more popular Open source More consumer oriented, less business-related Linux vs. Mac OS X Similar origins: OS X is based on BSD OS X is a more polished Unix than Linux Proprietary software AND hardware (that might change soon)

Linux Distributions Linux kernel, along with tools and applications - distribution No official distribution Several distributions available free: Ubuntu (free CDs!) Fedora (Red Hat) Mandrake Gentoo Commercial (supported) distributions available Biggest difference: installation customization user interface hardware support applications

Getting Help Various available resources Books Any Oreilly book for specific purposes Linux: The Textbook : Sarwar, Koretsky, Sarwar HOWTOs Specialized step-by-step tutorials, well written, detailed Hundreds available man pages Google!! Various Forums Helpful advice is available Mailing lists Every product has a mailing list Great for getting info, and cutting edge announcements