Unix

UNIX
Ken Thompson (links) und Dennis Ritchie (rechts)
Ken Thompson and Dennis Ritchie
base data
developers: Ken Thompson, Dennis Ritchie, Douglas McIlroy, and. A.
Version: freely, publicly:
Legally protected UNIX V7 (
1979), commercially:
SCO open server 6,0 (June 2005)
SCO UnixWare 7.1.4 (June 2004)
family tree: -
Architectures:
License: until 1981: None (freely)
starting from 1981: Prop. guessing acre (AT&T, Novell, SCO, SCO Group)
other: -
Website: www.unix.org

UNIX [ˈjuːnɪks] is a multi-user operating system. Itbecame at the beginning of the 70's 20. Century of Bell Laboratories for the support of the software development develops. Unix designation generally linguistic usage of operating systems, either their origin in the Unix system of AT&T (original Bell Laboratories) of the 70's has or itsConcepts implement.

Since UNIX is a registered brand name the open Group, only certified systems may bear the name UNIX. One assigns also operating systems such as Linux nevertheless to the Unix family. In the technical literature one uses usually Unix as name for unix well-behavedSystems, while one uses UNIX (in capital letters or Kapitälchen) in addition, certified systems to mark.

Among all these systems, which can be divided in Unix derivatives and Unix well-behaved operating systems, for example the BSD ranks - systems, Mac OS X, HP-UX, AIX, IRIX and Solaris. Some other systems such as GNU, Linux or QNX are not in the historical sense Unix derivatives, since they are not based on the original Unix source text, but were separately developed. BSD was originally based on Bell lab source texts,these were completely removed however to center of the 90's.

To table of contents

characteristics

The Unix Kernel has access to the hardware over device drivers alone and administers processes. Besides it places the file system to the order, in modern variants additionally the network minutes pile. System calls from processes serve for starting (system calls fork, EXEC)and taxes of further processes as well as for communication with the file system. Accesses to the device drivers are illustrated on accesses to special files in the file system. Thus files and devices from view of the processes and thus application programs are as far as possible standardized(System calls open, READ, write,…). A multiplicity of programs including a cent coil system and a text record program (troff) complete the system.

The file system is organized as hierarchical listing with arbitrary sublists, a then new concept, that todayeverywhere is natural. Root listing (root listing) of this hierarchy is the listing „/“. One of the outstanding basic concepts of UNIX are, also disk and CD drive assemblies, further non removable disks own or strange computer, terminal, to illustrate tape-units and others special files in the file system. „Everything is a file “is a basic principle of Unix. This generalized file term belongs to the nature of UNIX and makes a simple, uniform interface possible for most diverse applications. In some UNIX derivatives even processes and their characteristics to files are illustrated (proc file system).

The command interpreter, Shell, - under Unix a normal process without privileges - as well as numerous standard commands make an unequalled simple in/expenditure bypass for the user possible into these files, and over Pipes communication between processes.

A large collection ofsimple commands, the UNIX toolbox, can be combined in such a way with the help of the programming possibilities of the command interpreter and complicated tasks to take over. It is frequently avoided by the combinability of to a large extent standardized tools that one writes programs specialized in each case for „tasks of A MARk “or simpler administration workmust, as this is in other operating systems frequently the case.

To the important characteristics of a typical Unixsystems belong: high stability, multi-user, multitasking (meanwhile also Multithreading), storage protection and virtual memory (first implements in the BSD line), TCP/IP - network support(likewise first in the BSD - line), outstanding Scriptingeigenschaften, a fully developed Shell and a multiplicity of tools (see university X-commands) and Daemonen. Operating systems of Unix workstations as well as Unix derivatives contain usually a graphic user surface based on X11.

Unix is historically closely linked with the programming language C - both help themselves mutually to the break-through, and so C is also today still the preferential language under Unixsystemen.

the name Unix

the system was called originally Unics (latershortened on Unix), an allusion on the Multics - system. The name Unics was interpreted gladly also as UNIplexed information and Computing service, however this is a subsequent interpretation - neither Unics nor Unix or UNIX are acronyms.

The discussion,which name is now the more correct, UNIX or Unix, inflames again and again again. Unix the older name, UNIX than name is historical dipped only 1974 up for purely aesthetic reasons.

history

for information in more detail see History of Unix.

Ken Thompson provided the first version of Unix to 1969 in assembler language on the DEK PDP-7 as alternative to Multics. As one of the first programs for the new operating system core Thompson and Ritchie wrote the play Space Travel to plumb over which for interfaces it would need. The 1972 - 1974 in C implemented system completely again together with a C-compiler to different universities were free of charge distributed - from it developed the BSD - line ofUnix. AT&T tried finally, Unix profitably to marked out, from which those developed for system V line of Unix. Into the 1980er years became Unix the dominating operating system at the universities, and it existed an abundance of most diverse Unix derivatives, all this in anyForm of the two main lines it descended with which slowly need according to standardisation developed.

current right distribution

the rights at the source code lie according to own statement with the SCO Group (whereby Novell this however partly denies; see SCO v. Novell).The rights at the registered trade mark lie against it with the open Group.

and

extended the system changed standards for each manufacturer in the 80's 20. Century after own conceptions. Versions with different abilities, commands developed,Command options and program libraries. In order 1985 began to standardize those IEEE first, the interfaces for application programs. From this the IEEE developed 1003 - standard, which is called on suggestion of smelling pool of broadcasting corporations Stallman POSIX. It consists itself today of approximately 15 documents,with all aspects of Unix systems like the command line interpreter (POSIX writes compellingly the grain Shell forwards), the university X-commands and their options, the input/output and other one concern.

The prices the IEEE for the pos ix-documentation are very high, the publication are by copyrightforbidden. In more recent time therefore a tendency is to the single Unix Specification - standard the open Group to register. This standard is openly, in the Internet freely available and accepts suggestions of everyone.

free Unix derivatives

to Unix V7 1979, the source code appeared by Unix against refunding the copying and data medium costs at universities was distributed. Unix had thereby the character of a free, portable operating system. The code was used in lectures and publications and could after own conceptions changed and supplementedbecome. The University of Berkeley developed its own distribution with substantial extensions, the Berkeley Software Distribution (BSD).

In the early 80's decided AT&T, Unix to marked out; at&T source code could be made publicly accessible starting from this time no longer. Also thoseUse in lectures etc. was impossible. Also on BSD which are based systems were raised - there a part of the code of AT&T came - high royalties.

Many companies the licensed UNIX source code and brought their own variants on the market, even Microsoft time an Unix in the offer had with Xenix some.

The unavailability of the source code arranged 1983 smelling pool of broadcasting corporations Stallman to bring the GNU project (G nu is n ot U nix “) into being. A goal of the project was a free, Unix compatible system.Until 1990 the project had developed, however all substantial parts - inclusive the GNU C compiler - with exception of the Kernels.

1987 appeared the instructional system Minix, developed by Andrew S. Tanenbaum to the Vrije Universiteit Amsterdam. Minix was a Unix clonewith Mikrokernel, C compilers, editor and many commands, which on undemanding PC - hardware ran. The source code was part of the scope of supply. It was commercial, due to its very low price approximated it a free system however much. Howbefore times Unix served this system many as starting point for own experiments.

1991 worked the student Linus Torvalds on a terminal emulator, with which he wanted to access a university computer. With the time it inserted file system access and many other useful features.Soon he noticed that he programmed more than one terminal emulator. It published the SOURCE code in the newsgroup comp.os.minix as operating system, which should be executable on Intel - 386er - a PC. First to be project Freax should be called. There the overeager administrator“, called he assigned it simply in such a way to the University of it as Login for its Ftp Repository „Linux. In the SOURCE code of the version 0.01 of Linux still the name Freax comes forwards („Makefile for the FREAX kernel “).

The pos ix-standard and the GNU project, all thisif tools force such as compilers and Shell offer, offered a suitable way there. Torvalds used the min ix-system and the GNU C compiler as basis. It wrote a core, which it called Linux. Whereupon it transferred the software tools and libraries of the GNU project. ThisTools offered free operating system in combination with the Linux core the basis for a pos-ix-faithful. See also history of Linux.

1992 appeared with 386BSD von Bill Jolitz a further free system for 80386-Prozessoren. It consisted of a Patch for thosenot of AT&T and a further free very advanced operating system for Intel processors formed coming free parts of the BSD distribution.

1994 published Berkeley with 4.4BSDLite the last version of their distribution, which was released from AT&T source code. This formed the basis together with 386BSDfor NetBSD, FreeBSD and shortly thereafter OpenBSD.

2000 released Apple the source text of the operating system Darwin, a component of Mac OS X. It is based on 4.4BSD and Mach - Mikrokernel.

Since 2005 is also Solaris (version 10)in the current in each case version for the use free of charge available. Solaris runs on 32-bit processors (x86) of AMD and Intel as well as on 64-bit systems with Suns UltraSPARC and so-called x64-Systemen such as z. B. AMDs Opteron. For access to sourcesand cooperation inclusive. Extension is available it in the version OpenSolaris, which does not differ functionally from the binary version. Sun Microsystems required however a registration and has own license regulations, which deviate from the GPL.

A further Unix “derivative” is LUnix (briefly for little Unix), which makes a Unix similar system available on Commodore C64 or C128.

publication dates

the following compilation gives only a rough overview. Only the most important systems are mentioned. These have in each case theirown versions and their own history of the development.

Year name note/manufacturer
1969 UNICS first version of Bell Laboratories
1970 - 75 UNIX V1-V5 Time sharing system Bell lab
1976 UNIX V6 (6th edition) Bell lab
1977 first Berkeley Software Distribution (BSD)
1978 2BSD second Berkeley Software Distribution
1979 UNIX V7 (7th edition) last version of Bell lab with free source code
1980 UNIX 32V Portierung of the UNIX V7 on VAX - computer
1980 XENIX OS Unix version of the company Microsoft, late company SCO
1980 3BSD and 4BSD Berkeley Portierung on VAX computers
1981 UNIX system III first commercial version of Bell lab
1982 SunOS, 1,0 Unix version of the company Sun Microsystems
1983 start of the GNU project (GNU: Gnu is emergencyUnix - GNU is not Unix)
1983 UNIX system V Bell lab
1983 Ultrix Unix version of the company Digital Equipment corporation (DEK)
1983 Sinix Unix version of the company Siemens
1983 Coherent Unix similar system of the Marks of Williams company
1983 4.2BSD
1984 Start of Mach - Mikrokernel project to the Carnegie Mellon University (California).
1986 AIX 1,0 Unix version of the company IBM
1986 A/UX Unix version of the company Apple
1986 HP-UX 1,0 Unix version of the company Hewlett-Packard (HP)
1987 Minix 1,0 Unix clone of the Vrije university, Amsterdam
1988 IRIX Unix version of the company Silicon graphics
1989 SCO UNIX Unix version the one far spreading at the market found
1990 OSF/1 Unix clone the open software Foundation
1991 4.3BSD Net/2 BSD version without AT&T code, to incompletely
1991 Linux oriented at Minix, large spreading
1992 Solaris 2,0 company Sun Microsystems
1992 386BSD Patch for BSD4.3 Net/2 for Intel processors
1992 UnixWare 1,0 Unix version by Univel (AT&T & Novell)
1993 UnixWare 1,1 Unix version of Novell
1994 4.4BSDEncumbered and 4.4BSDLite (without Bell lab code)
1994 NetBSD 1.0 based on 4.4BSDLite
1994 FreeBSD 1,0 based on 4.3BSD Net/2 (shortly thereafter 2,0 on 4.4BSDLite)
1994 Tru64 successor outgoing from
OSF/1 1995 SCO open servers of 5 successors from SCO UNIX and open Desktop - UNIX SVR3.2
V5.0.0 1995 OpenBSD - projectfrom NetBSD
the Unix system lab of Novell takes over 1995 UnixWare 2 SCO
1996 AT&T arranges the Bell lab into the enterprise Lucent Technologies
2000 Darwin company Apple, based on Mach and 4.4BSD
2004 SCO UnixWare 7.1.4 UNIX version of thesupposed source code right owner SCO Group
2005 Solaris 10 (SunOS 5,10) to company Sun Microsystems
2005 SCO open server 6,0 UNIX version of the alleged source code right owner SCO Group

see also

literature

  • The BellSystem Technical journal, volume. 57, July August 1978, No. 6, part 2, S. 1897-2312
  • Brian W. Kernighan, Rob Pike: The Unix toolbox - programming with UNIX, (German translation), Hanser publishing house, Munich 1986, ISBN 3446142738
  • E. Foxley: Unix for superuser. Addison-Wesley, 1988, ISBN 3-925118-24-1
  • J. Gulbins, K. Obermayr: UNIX system V.4. Terms, concepts, command, interfaces. 4. Aufl. 1995, ISBN 3540588647
  • Jerry Peek, Grace Todino, John strand: UNIX. A practical entrance. O’Reilly Verlag, 2002, ISBN 3897211572

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