OPEARTING SYSTEM

Abstract- We looked at several different operating While initially intended for use inside system specifications trying to determine which OS the Bell System, Unix developed into a would be the most versatile for our business standard for academia environment. It should be taken into strong consideration that although an operating system's during the late 1970s and 1980s. AT&T documentation will state the minimum system tried to commercialize it by licensing the OS requirements is low, a user may not agree to the level of to third-party vendors, leading to a variety of functionality. In short, the bare requirements are often both academic (e.g.,BSD) and commercial not acceptable performance to your client. We variants of Unix (such as ) and compared Windows XP Home & Professional, Unix, eventually to the "Unix wars" between , Knoppix, Fedora and Macintosh's OS X, to see what requirements were needed to run the operating groups of vendors. AT&T finally sold its systems...The UNIX* operating system was designed to rights in Unix to in the early 1990s, let a number of programmers access the at which then sold its Unix business to the same time and share its resources. the (SCO) in [6] INTRODUCTION 1995, but the UNIX trademark passed to the industry standards consortium The Open Unix (all-caps UNIX for the trademark) is Group, which allows the use of the mark for certified operating systems compliant with a multitasking, multiuser computer operatin the Single UNIX Specification. g system that exists in many variants. The original Unix was developed at AT&T's Bell OVERVIEW OF UNIX Labs research center by Ken OPEARTING Thompson, Dennis Ritchie, and others.[3] From the power user's or The UNIX* operating system was designed programmer's perspective, Unix systems are to let a number of programmers access the characterized by a modular design that is computer at the same time and share its sometimes called the "Unix philosophy," resources. meaning the OS provides a set of simple The operating system coordinates the use of tools that each perform a limited, well- the computer's resources, allowing one defined function,[4] with a person, for example, to run a spell check unified filesystem as the main means of program while another creates a document, communication[3] and a shell scripting and lets another edit a document while another command language to combine the tools to creates graphics, and lets another user perform complex workflows. format a document -- all at the same time, with each user oblivious to the activities of The programming language was designed the others. by Dennis Ritchie as a systems The operating system controls all of the [5] programming language for Unix, allowing commands from all of the keyboards and all for portability beyond the initial PDP- of the data being generated, and permits 11 development platform and the use of Unix on numerous computing platforms. each user to believe he or she is the only person working on the computer. This real-time sharing of resources t. make UNIX one of the most powerful operating systems ever. While initially designed for medium-sized minicomputers, the operating system was soon moved to larger, more powerful mainframe . As personal computers grew in popularity, versions of UNIX found their way into these boxes, and a number of companies produce UNIX- based machines for the scientific and programming communities.

EVOLUTION OF UNIX TIME

SHARING SYSTEM

IThe first version of UNIX was created in 1969 by Kenneth Thompson and ORIGIN OF UNIX Dennis Ritchie, system engineers at AT&T's OPEARTING SYSTEM . It went through many revisions and gained in popularity until 1977, when it 1969 The Beginning The was first made commercially available by starts back in 1969, when Ken Thompson, Interactive Systems Corporation. Dennis Ritchie and others started working At the same time a team from the University on the "little-used PDP-7 in a corner" at Bell of California at Berkeley was working to Labs and what was to become UNIX. improve UNIX. In 1977 it released the first 1971 First Edition It had a assembler for a Berkeley Distribution, which PDP-11/20, file system, fork(), roff and ed. became known as BSD. Over time this won It was used for text processing of patent favour through innovations such as the C documents. shell. 1973 Fourth Edition It was rewritten in C. Meanwhile the AT&T version was This made it portable and changed the developing in different ways. The 1978 history of OS's. release of Version 7 included the Bourne 1975 Sixth Edition UNIX leaves home. Also Shell for the first time. By 1983 commercial widely known as Version 6, this is the first interest was growing and Sun to be widely available out side of Bell Labs. Microsystems produced a UNIX The first BSD version (1.x) was derived workstation. System V appeared, directly from V6. descended from the original AT&T UNIX 1979 Seventh Edition It was a and the prototype of the more widely used "improvement over all preceding and variant following Unices" [Bourne]. It had C, UUCP and the Bourne shell. It was ported to the VAX and the kernel was more than 40 Brand. OSF/1 debuts. Plan 9 from Bell Labs Kilobytes (K). ships. 1991 1980 Xenix introduces Xenix. (USL) becomes a company - majority- 32V and 4BSD introduced. owned by AT&T. Linus Torvalds 1982 System III AT&T's UNIX System commences Linux development. Solaris 1.0 Group (USG) release System III, the first debuts. public release outside Bell Laboratories. 1992 1992 SVR4.2 USL releases UNIX SunOS 1.0 ships. HP-UX introduced. Ultrix- System V Release 4.2 (Destiny). October - 11 Introduced. XPG4 Brand launched by X/Open. 1983 System V Computer Research Group December 22nd Novell announces intent to (CRG), UNIX System Group (USG) and a acquire USL. Solaris 2.0 ships. third group merge to become UNIX System 1993 1993 4.4BSD 4.4BSD the final Development Lab. AT&T announces UNIX release from Berkeley. June 16 Novell System V, the first supported release. acquires USL Late 1993 SVR4.2MP Novell Installed base 45,000. transfers rights to the "UNIX" trademark 1984 4.2BSD University of California at and the Single UNIX Specification to Berkeley releases 4.2BSD, includes TCP/IP, X/Open. COSE initiative delivers "Spec new signals and much more. X/Open 1170" to X/Open for fasttrack. In December formed. Novell ships SVR4.2MP , the final USL 1984 SVR2 System V Release 2 introduced. OEM release of System V At this time there are 100,000 UNIX 1994 1994 Single UNIX Specification installations around the world. BSD 4.4-Lite eliminated all code claimed to 1986 4.3BSD 4.3BSD released, including infringe on USL/Novell. As the new owner internet name server. SVID introduced. NFS of the UNIX trademark, X/Open introduces shipped. AIX announced. Installed base the Single UNIX Specification (formerly 250,000. Spec 1170), separating the UNIX trademark 1987 SVR3 System V Release 3 including from any actual code stream. STREAMS, TLI, RFS. At this time there are 1995 1995 UNIX 95 X/Open introduces 750,000 UNIX installations around the the UNIX 95 branding programme for world. IRIX introduced. implementations of the Single UNIX 1988 POSIX.1 published. Open Software Specification. Novell sells UnixWare Foundation (OSF) and business line to SCO. Digital UNIX (UI) formed. Ultrix 4.2 ships. introduced. UnixWare 2.0 ships. 1989 1989 AT&T UNIX Software OpenServer 5.0 debuts. Operation formed in preparation for spinoff 1996 1996 forms as a of USL. 1.0 ships. merger of OSF and X/Open. 1990 1989 SVR4 UNIX System V 1997 1997 Single UNIX Specification, Release 4 ships, unifying System V, BSD Version 2 The Open Group introduces and Xenix. Installed base 1.2 million. Version 2 of the Single UNIX Specification, 1991 1990 XPG3 X/Open launches XPG3 including support for realtime, threads and 64-bit and larger processors. The the intelligence of the user to deduce reasons specification is made freely available on the for failure. web. IRIX 6.4, AIX 4.3 and HP-UX 11 ship. FEATURE OF UNIX 1998 1998 UNIX 98 The Open Group OPEARTING SYSTEM introduces the UNIX 98 family of brands, The features that made UNIX a hit from the including Base, Workstation and Server. start are: First UNIX 98 registered products shipped · Multitasking capability by Sun, IBM and NCR. The Open Source · Multiuser capability movement starts to take off with · Portability announcements from Netscape and IBM. · UNIX programs UnixWare 7 and IRIX 6.5 ship. · Library of application software 1999 1999 UNIX at 30 The UNIX system Multitasking reaches its 30th anniversary. Linux 2.2 Many computers do just one thing at a time, kernel released. The Open Group and the as anyone who uses a PC or laptop can IEEE commence joint development of a attest. Try logging onto your company's revision to POSIX and the Single UNIX network while opening your browser while Specification. First LinuxWorld opening a word processing program. conferences. Dot com fever on the stock Chances are the processor will freeze for a markets. Tru64 UNIX ships. few seconds while it sorts out the multiple 2000 2001 Single UNIX Specification, instructions. Version 3 Version 3 of the Single UNIX UNIX, on the other hand, lets a computer do Specification unites IEEE POSIX, The Open several things at once, such as printing out Group and the industry efforts. Linux 2.4 one file while the user edits another file. kernel released. IT stocks face a hard time at This is a major feature for users, since users the markets. The value of procurements for don't have to wait for one application to end the UNIX brand exceeds $25 billion. AIX before starting another one. 5L ships. Multiusers 2003 ISO/IEC 9945:2003 The core volumes All flavors of UNIX are multi-user systems; of Version 3 of the Single UNIX a number of users can have accounts on one Specification are approved as an machine and even use it simultaneously if international standard. The "Westwood" test hardware allows. In fact, many of the parts suite ship for the UNIX 03 brand. Solaris 9.0 of the operating system are organized with E ships. Linux 2.6 kernel released. multiple different users in mind. The uniqueness of UNIX The most powerful and important user on he UNIX system is successful because the any UNIX system is the root user. This is minimum number of keystrokes achieve the the account for the system administrator and maximum effort. In addition, the system has all possible privileges to all parts of the says very little to explain errors and relies on machine. The root user is usually the one responsible for: a minimum of code changes. At a time when 1. keeping the machine up and working different computer lines of the same vendor properly didn't talk to each other -- yet alone 2. setting disk quotas (limits on the machines of multiple vendors -- that meant a amount of hard drive space each user can great savings in both hardware and software write to) upgrades. 3. permissions for use of software on the It also meant that the operating system could machine (so ordinary users cannot wipe out be upgraded without having all the each other's work or take over control of the customer's data inputted again. And new computer) versions of UNIX were backward 4. installing software for global compatible with older versions, making it (everybody's) use easier for companies to upgrade in an 5. applying software patches when bugs orderly manner. are found and fixed UNIX tools 6. setting system policies (like security UNIX comes with hundreds of programs and access control) that can divided into two classes: If you have your own system, then you are · Integral utilities that are absolutely the root user of your system. Since, the root necessary for the operation of the computer, user account is normally reserved strictly for such as the command interpreter, and system administrator tasks. · Tools that aren't necessary for the If there are a lot of users on a particular operation of UNIX but provide the user with UNIX machine, then the concept of groups additional capabilities, such as typesetting becomes important. Each of these groups capabilities and e-mail. would have a different set of privileges, perhaps different set of specialized programs Tools can be added or removed from a they are allowed to use, and a different set of UNIX system, depending upon the files on the computer they are allowed to applications required. access. UNIX Communications E-mail is commonplace today, but it has The same design that permits multitasking only come into its own in the business permits multiple users to use the computer. community within the last 10 years. Not so The computer can take the commands of a with UNIX users, who have been enjoying number of users -- determined by the design e-mail for several decades. of the computer -- to run programs, access UNIX e-mail at first permitted users on the files, and print documents at the same time. same computer to communicate with each other via their terminals. Then users on System portability different machines, even made by different A major contribution of the UNIX system vendors, were connected to support e-mail. was its portability, permitting it to move And finally, UNIX systems around the from one brand of computer to another with world were linked into a world wide web decades before the development of today's The three levels of the UNIX system: kernel, World Wide Web. shell, and tools and applications. Applications libraries The kernel UNIX as it is known today didn't just The heart of the operating system, the kernel develop overnight. Nor were just a few controls the hardware and turns part of the people responsible for it's growth. As soon system on and off at the programer's as it moved from Bell Labs into the command. If you ask the computer to list universities, every computer programmer (ls) all the files in a directory, the kernel tells worth his or her own salt started developing the computer to read all the files in that programs for UNIX. directory from the disk and display them on Today there are hundreds of UNIX your screen. applications that can be purchased from The shell third-party vendors, in addition to the There are several types of shell, most applications that come with UNIX. notably the command driven Bourne Shell How UNIX is organized and the C Shell (no pun intended), and The UNIX system is functionally organized menu-driven shells that make it easier for at three levels: beginners to use. Whatever shell is used, its · The kernel, which schedules tasks and purpose remains the same -- to act as an manages storage; interpreter between the user and the · The shell, which connects and interprets computer. users' commands, calls programs from The shell also provides the functionality of memory, and executes them; and "pipes," whereby a number of commands · The tools and applications that offer can be linked together by a user, permitting additional functionality to the operating the output of one program to become the system input to another program.

UNIX COMMAND

Command Description cat Display File Contents Changes Directory to dirname chgrp change file group chmod Changing Permissions cp Copy source file into destination file Determine file type find Find files grep Search files for regular expressions. head Display first few lines of a file ln Create softlink on oldname ls Display information about file type. mkdir Create a new directory dirname more Display data in paginated form. mv Move (Rename) a oldname to newname. pwd Print current working directory. rm Remove (Delete) filename rmdir Delete an existing directory provided it is empty. tail Prints last few lines in a file. touch Update access and modification time of a file.

COMPARISON OF WINDOWS NT dollars only 20 years later would have AND UNIX AS OPEARTING SYSTEM seemed like science fiction to them...

Comparison of Windows NT and Unix as UNIX SECURITY Operating Systems Incomplete Essay In the late 1960s a combined project between An Overview of UNIX Security The researchers at MIT, Bell Labs and General purpose of this paper is to analyze the Electric led to the design of a third security of UNIX. Considerations shall be generation of computer operating system given regarding generalized security aspects known as MULTICS (MULTiplexed of a typical UNIX system. The ultimate Information and Computing Service). It was scope of the following presentation shall envisaged as a computer utility, a machine remain within the boundaries of a few of the that would support hundreds of more critical UNIX security aspects. Of simultaneous timesharing users. They particular note will be discussion regarding envisaged one huge machine providing standard user access, root access, file system computing power for everyone in Boston. security, and internet access precautions. The idea that machines as powerful as their This will not focus on specific measures GE-645 would be sold as personal used to implement security, but rather will computers costing only a few thousand investigate both pros and cons typical of a

UNIX .

COMPARISON OF MICROSOFT simultaneously but not multiple WITH UNIX users).  UNIX is a machine independent Comparing Microsoft DOS with UNIX As is operating system. Not specific to just suggestive of its name, an operating system one type of computer hardware. (OS) is a collection of programs that operate Designed from the beginning to be the personal computer (PC). Its primary independent of the computer purpose is to support programs that actually hardware. do the work one is interested in, and to allow  UNIX is a software development competing programs to share the resources environment. Was born in and of the computer. However, the OS also designed to function within this type controls the inner workings of the computer, of environment. acting as a traffic manager which controls the flow of data through the system and initiates the starting and stopping processes, and as a means through which software can access the hardware and system software.. REFERNCES CONCLUSION 1. McIlroy, M. D. (1987). A Research Unix  UNIX is a computer operating reader: annotated excerpts from the system. Programmer's Manual, 1971– 1986 (Technical report). CSTR. Bell Labs.  An operating system is the program 139. that controls all the other parts of a 2. Jump up^ Ritchie, D. M.; Thompson, K. computer system, both the hardware (1974). "The UNIX Time-Sharing and the software. It allocates the System". CACM 17 (7): 365–375. computer's resources and schedules 3. ^ Jump up to:a b Ritchie, D.M.; Thompson, tasks. It allows you to make use of the K. (July 1978). "The UNIX Time-Sharing facilities provided by the system. System". Bell System Tech. J. (USA: American Tel. & Tel.) 57 (6): 1905– Every computer requires an operating 1929. doi:10.1002/j.1538- system. 7305.1978.tb02136.x. Retrieved December  UNIX is a multi-user, multi-tasking 9, 2012. operating system. Multiple users may 4. Jump up^ Raymond, Eric (2003-09- have multiple tasks running 19). The Art of Unix Programming. simultaneously. This is very different Addison-Wesley. ISBN 0-13-142901-9. from PC operating systems such as Retrieved 2009-02-09. 5. Jump up^ Ritchie, Dennis M. (January MS-DOS or MS-Windows (which 1993). "The Development of the C allows multiple tasks to be carried out Language". Retrieved 1 January 2008. "The scheme of type composition adopted by C owes considerable debt to Algol 68, 11. Jump up^ Kernighan, Brian W. Pike, although it did not, perhaps, emerge in a Rob. The UNIX Programming form that Algol's adherents would approve Environment. 1984. viii of." 12. Jump up^ 8:30 AM (29 September 6. Jump 2010). "Unix’s Revenge". asymco. up^ http://www.novell.com/news/press/arch Retrieved 2010-11-09. ive/1995/12/pr95274.html 13. Jump up^ Stuart, Brian L. 7. Jump up^ What is a "Unix-like" operating (2009). Principles of operating systems: system? Unix.org FAQ design & applications. Boston, 8. Jump up^ Apple Inc. - UNIX 03 Register Massachusetts: Thompson Learning. of Certified Products, The Open Group p. 23. ISBN 1-4188-3769-5. 9. Jump up^ "The Elements of Operating- 14. Jump up^ Ritchie, Dennis M. "The System Style". Evolution of the Unix Time-sharing 10. Jump up^ Powers, Shelley; Peek, Jerry; System". Retrieved 2009-11-29. O'Reilly, Tim; Loukides, Mike (2002). Unix Power Tools.ISBN 0-596-00330-7.