Linux Basics CS 302
Outline • What is Unix? • What is Linux? • Virtual Machine.
What is Unix? • An operating system developed in the 1960s. • It is multi-user and multi-tasking operating system. • The most popular varieties of UNIX are Sun Solaris, GNU/Linux, and MacOS X. • The UNIX operating system is made up of three parts; the kernel, the shell and the programs
What is Unix (Cont.) • The Kernel : a program that manages computer resources and handles system calls. • The Shell : a command line interpreter (CLI) that acts as an interface between the user and kernel.
Linux History • GNU Project: • Started at 1983 by Richard Stallman. • Goal: creating a UNIX-like free operating system. • His vision: software should be free from restrictions against copying or modification in order to make better and efficient computer programs. • By 1991 GNU created a lot of tools, but there was still no operating system.
Linux History (Cont.) • In 1991: • Linux kernel is developed by LinusTorvalds. • combining Linux kernel with the not-quite-complete GNU system resulted in a complete free operating system called Linux. • Today’s Linux distribution consists of: • Linux Kernel • GNU (GNU is Not Unix) Software • Software Package management • Others
Linux is Open Source Software • When programmers on the Internet can read, redistribute, and modify the source for a piece of software, it evolves • People improve it, people adapt it, people fix bugs. And this can happen at a speed that, compared to conventional software development.
Linux Distributions • Various organizations package the Linux kernel and system programs as Linux distributions • Such as : Ubuntu, Red Hat, and Mandriva.
Common Linux features • Multiuser: • Multiple users can log in and working on the system at the same time • Multiuser systems divide computer resources among multiple users, allowing for more efficient use of these resources. • Multitasking: • it is possible to have many programs running at the same time • Graphical User Interface (X Window System) • Hardware support • you can configure support for almost every type of hardware that can be connected to a computer • Networking connectivity: • Linux offers support for a variety of local area network boards, modems, and serial devices.
Common Linux features (Cont.) • Application support • a wide range of freeware and shareware software is available for Linux. • Most of Linux is written in the C programming language. When written in a portable style, C programs can be moved from one platform (processor or CPU-based system) to another by simply recompiling the code.
Virtual Machine • A virtual machine (VM) is a "completely isolated guest operating system installation within a normal host operating system“ • Virtualization lets you run multiple virtual machines on a single physical machine, with each virtual machine sharing the resources of that one physical computer across multiple environments. • VMware is an example of virtual machines software