Everything you ever wanted to know about UNIX

Presentation created by John Sklar

Modified January 2010 by Kristine Diener

What is UNIX?

• Unix is the ultimate multi-user multi-tasking system allowing multiple users to use multiple aps at the same time never knowing that anyone else is on the machine.

• This sharing of resources make UNIX one of the most powerful operating systems ever written.

• Although UNIX was developed by programmers for programmers, it provides an environment so powerful and flexible that it is found in businesses, sciences, academia, and industry, its price makes it the perfect place to develop free applications.

• Because of the powerful multi-tasking ability, it has become popular with communications system designers and many telecommunications switches and transmission systems also are controlled systems based on UNIX.

History

• Developed at Bell labs, now Lucent Technologies, in the late 60’s, UNIX has been able to evolve with the computer industry partly because of its extensible nature.

• The very open source nature of the operating system made it easy for individuals and groups to develop their own “flavor” of the OS. Some for specific uses and reasons.

History

• Unix prospered, and grew because users, mostly in large corporations and universities, could extend the language to do whatever task was needed.

• The command line interface was much like the DOS prompt of MS-Dos.

• The language did need specific hardware but the early development of TCP/IP made the use of this operating system compelling to say the least.

History

• An operating system that was royalty free, open source and easily extensible was too good to be true.

• The addition of internet, i.e. networking, protocols made the combination indispensable to the growth of network systems.

• Even today, Sun Microsystems among other vendors, provide powerful, robust versions of UNIX that are fully supported and maintained.

The features that made UNIX

• Multitasking capability • Multiuser capability • Portability • UNIX programs • Library of application software

Multitasking

• Most computers do one thing at a time,. Try logging onto your school’s network while opening your browser while opening a word processing program. The processor will freeze for a few seconds while it sorts out the instructions.

• UNIX, lets a computer do several things at once, such as printing out one file while the user edits another file. This might include dozens or more users accessing the same web ap at the same time. This is a major feature for users, since users don't have to wait for one application to end before starting another one.

The features that made UNIX

• Multitasking capability • Multiuser capability • Portability • UNIX programs • Library of application software

Multiusers

• This same design permits multiple users. The computer can take the commands of a number of users to run programs, access files, and print documents at the same time.

• The computer can't tell the computer to do all the requests at once, but it does prioritize the requests to keep things orderly. It also lets several users access the same document by compartmentalizing the document so that the changes of one user don't override the changes of another user.

The features that made UNIX

• Multitasking capability • Multiuser capability • Portability • UNIX programs • Library of application software

System portability

• A major contribution of the UNIX system was its portability, moving from one platform to another. In the early days computers couldn’t talk at all much less allow for command lines to be interchangeable.

• This also meant that the operating system could be upgraded or changed without having all the customer's data inputted again. New versions of UNIX were usually backward compatible with older versions, making it easier for companies to upgrade in an orderly manner.

The features that made UNIX

• Multitasking capability • Multiuser capability • Portability • UNIX programs • Library of application software

UNIX Software tools

• Tools and utilities that are absolutely necessary for the operation of the computer, such as the command interpreter.

• Tools that aren't necessary for the operation of UNIX but provide the user with additional capabilities.

• Tools can be added or removed from a UNIX system, depending upon the applications required.

The features that made UNIX

• Multitasking capability • Multiuser capability • Portability • UNIX programs • Library of application software

UNIX Communications

• UNIX e-mail at first permitted users on the same computer to communicate with each other via their terminals. Then users on different machines, even made by different vendors, were connected to support e-mail. And finally, UNIX systems around the world were linked into a world wide web decades before the development of today's World Wide Web.

Applications libraries

• UNIX as it is known today didn't just develop overnight. Nor was it the work of one person or group. As soon as it moved from Bell Labs into universities, computer programmers began to develop applications.

• Today there are hundreds of UNIX applications that can be purchased from third-party vendors, in addition to the applications that come with UNIX.

UNIX systems are organized into three levels:

• The kernel, which schedules tasks and manages storage and devices.

• The shell, connecting users' commands to the Kernel

• The tools and applications that offer additional functionality to the operating system based on users needs.

The kernel

• The heart of the operating system, the kernel controls the hardware and turns part of the system on and off at the programmer's command.

• You give the kernel a command it executes

The shell

• The shell acts as an interpreter between the user and the computer.

• Some modern shells also provide a GUI with command line options.

Why Linux?

Cartoon licensed under a Creative Commons Attribution-Noncommercial license.net attribution to http://xkcd.com : http://imgs.xkcd.com/comics/linux_user_at_best_buy.png

Tools and applications

• There are hundreds of tools available to UNIX users. Some free and some from vendors.• word processing• business applications• Programming• games

• Many Linux implementation come bundled with essential software including an office suite, accessories, a browser, games (LOL), and more

Creating a Live Disk

1. Choose a Linux implementation from Live CD Listhttp://www.livecdlist.com/

Creating a Live Disk

2. Download an ISO file that is about 600 or 700 MB

3. Burn to CD/ROM

Resources

• Linux Anecdotes http://liw.iki.fi/liw/texts/linux-anecdotes.html

• History of Linux https://netfiles.uiuc.edu/rhasan/linux/#In%20The%20Beginning

Thanks to http://www.bell-labs.com/history/unix/blcontributions.html