Unix Presentation

What is an Operating System An operating system (OS) is a program that allows you to interact with the computer -- all of the software and hardware on your computer Basically, there are two ways to interact with the computer 1. command-line 2.Graphical User Interface (GUI)

3 History of Unix originally developed in 1969 by a group of AT&T employees at Bell Labs, including Ken Thompson, Dennis Ritchie,Brain Kernighan,etc.. The Unix operating system was first developed in Assembly language, but by 1973 had been almost entirely recoded in C,

Unix Architecture

kernel: The kernel is the heart of the operating system. It interacts with hardware and most of the tasks like memory management, tash scheduling and file management. Shell: The shell is the utility that processes your requests. When you type in a command at your terminal, the shell interprets the command and calls the program that you want. The shell uses standard syntax for all commands. C Shell, Bourne Shell and Korn Shell are most famous shells which are available with most of the Unix variants.

Shells An interface between the Linux system and the user Used to call commands and programs An interpreter Powerful programming language – “Shell scripts” =.bat.cmd EXEC REXX Many available (bsh; ksh; csh; bash; tcsh)bashtcsh

What is Linux In Sept 1991, Linus Torvalds, a second year student of Computer Science at the University of Helsinki, developed the preliminary kernel of Linux, known as Linux version 0.0.1

Linux v/s Unix UNIX Operating System Names A few popular names: HP-UX IBM AIX Sun Solairs Mac OS X IRIX Linux Distribution (Operating System) Names A few popular names: Redhat Enterprise Linux Fedora Linux Debian Linux Suse Enterprise Linux Ubuntu Linux

Common Things Between Linux & UNIX Both share many common applications such as: GUI, file, and windows managers (KDE, Gnome) Shells (ksh, csh, bash) Various office applications such as OpenOffice.org Development tools (perl, php, python, GNU c/c++ compilers)

Unix File System Basics Linux files are stored in a single rooted, hierarchical file system – Data files are stored in directories (folders) – Directories may be nested as deep as needed Directories User home directories Data files root

Naming Files Files are named by – naming each containing directory – starting at the root This is known as the pathname /etc/passwd /home/neale/b

Features of Unix multi-user more than one user can use the machine at a time supported via terminals (serial or network connection). It does this by time-slicing the computer processor at regular intervals between the various users. multi-tasking more than one program can be run at a time hierarchical directory structure to support the organisation and maintenance of files

Advantages of Unix over Windows Security UNIX is considered 'more secure' while WINDOWS is considered 'less secure'. Open Source Linux is an open source we can get over internet. It’s source code is avialable we can change it according to our requirement. Free of Cost Free from Virus

Questions???

Thank You