Misplaced Pages

#256743

37-778: There are a number of Unix-like operating systems under active development, descended from the Berkeley Software Distribution (BSD) series of UNIX variants developed (originally by Bill Joy ) at the University of California, Berkeley , Department of Electrical Engineering and Computer Science. Since the early 2000s, there are four major BSD operating systems– FreeBSD , NetBSD , OpenBSD and DragonFly BSD , and an increasing number of other OSs forked from these, that add or remove certain features; however, most of them remain largely compatible with their originating OS—and so are not really forks of them. This

74-550: A genericized trademark . Some add a wildcard character to the name to make an abbreviation like "Un*x" or "*nix", since Unix-like systems often have Unix-like names such as AIX , A/UX , HP-UX , IRIX , Linux , Minix , Ultrix , Xenix , and XNU . These patterns do not literally match many system names, but are still generally recognized to refer to any UNIX system, descendant, or work-alike, even those with completely dissimilar names such as Darwin / macOS , illumos / Solaris or FreeBSD . In 2007, Wayne R. Gray sued to dispute

111-473: A POSIX compatibility layer and are not otherwise inherently Unix systems. Many ancient UNIX systems no longer meet this definition. Broadly, any Unix-like system that behaves in a manner roughly consistent with the UNIX specification, including having a " program which manages your login and command line sessions "; more specifically, this can refer to systems such as Linux or Minix that behave similarly to

148-470: A UNIX system but have no genetic or trademark connection to the AT&;T code base. Most free/open-source implementations of the UNIX design, whether genetic UNIX or not, fall into the restricted definition of this third category due to the expense of obtaining Open Group certification, which costs thousands of dollars. Around 2001 Linux was given the opportunity to get a certification including free help from

185-538: A historical connection to the AT&;T codebase. Most commercial UNIX systems fall into this category. So do the BSD systems, which are descendants of work done at the University of California, Berkeley in the late 1970s and early 1980s. Some of these systems have no original AT&T code but can still trace their ancestry to AT&T designs. These systems‍—‌largely commercial in nature‍—‌have been determined by

222-534: A large amount of code derived from FreeBSD. NetBSD is a freely redistributable, open source version of the Unix-derivative Berkeley Software Distribution (BSD) computer operating system. It was the second open source BSD descendant to be formally released, after 386BSD, and continues to be actively developed. Noted for its portability and quality of design and implementation, it is often used in embedded systems and as

259-455: A single user or process at a time. Another important feature of Unix-like systems is their modularity . This means that the operating system is made up of many small, interchangeable components that can be added or removed as needed. This makes it easy to customize the operating system to suit the needs of different users or environments. The Open Group owns the UNIX trademark and administers

296-462: A starting point for the porting of other operating systems to new computer architectures. OpenBSD is a Unix-like computer operating system descended from Berkeley Software Distribution (BSD), a Unix derivative developed at the University of California, Berkeley. It was forked from NetBSD in 1995. OpenBSD includes a number of security features absent or optional in other operating systems and has

333-662: A tradition of developers auditing the source code for software bugs and security problems. BSD was originally derived from Unix, using the complete source code for Sixth Edition Unix for the PDP-11 from Bell Labs as a starting point for the First Berkeley Software Distribution, or 1BSD . A series of updated versions for the PDP-11 followed (the 2.xBSD releases). A 32-bit version for the VAX platform

370-486: A variety of proprietary systems were developed based on it, including AIX , HP-UX , IRIX , SunOS , Tru64 , Ultrix , and Xenix . These largely displaced the proprietary clones. Growing incompatibility among these systems led to the creation of interoperability standards, including POSIX and the Single UNIX Specification . Various free, low-cost, and unrestricted substitutes for UNIX emerged in

407-472: Is IEEE Std 1003.1-2008. This version had 1833 interfaces, of which 1191 were in the System Interfaces section. Technical Corrigendum 1 mostly targeted internationalization, and also introduced a role-based access model. A trademark UNIX V7 (not to be confused with V7 UNIX , the version of Research Unix from 1979) was created to mark compliance with SUS Version 4. Technical Corrigendum 2

SECTION 10

#1732765028257

444-659: Is IEEE Std 1003.1-2017. SUSv3 totals some 3700 pages, which are divided into four main parts: The standard user command line and scripting interface is the POSIX shell, an extension of the Bourne Shell based on an early version of the Korn Shell . Other user-level programs, services and utilities include awk , echo , ed , vi , and hundreds of others. Required program-level services include basic I/O ( file , terminal , and network ) services. A test suite accompanies

481-515: Is a list of those that have been active since 2014, and their websites . FreeBSD is a free Unix-like operating system descended from AT&T UNIX via the Berkeley Software Distribution (BSD). FreeBSD currently has more than 200 active developers and thousands of contributors. Other notable derivatives include DragonFly BSD , which was forked from FreeBSD 4.8, and Apple Inc. 's macOS , with its Darwin base including

518-713: Is available for the version. In 2004, a new edition of the POSIX.1-2001 standard was released, incorporating two technical corrigenda. It is called IEEE Std 1003.1, 2004 Edition. Some informally call it POSIX.1-2004, but this is not an official identification. In December 2008, the Austin Group published a new major revision of SUS and POSIX. This is the Single UNIX Specification, Version 4 (SUSv4). This SUS consists of: The Base Specifications are technically identical to POSIX.1-2008 , which

555-521: The Apache web server and the Bash shell, are also designed to be used on Unix-like systems. One of the key features of Unix-like systems is their ability to support multiple users and processes simultaneously. This allows users to run multiple programs at the same time and to share resources such as memory and disk space. This is in contrast to many older operating systems, which were designed to only support

592-434: The Austin Group began to develop the combined standard that would be known as the core of Single UNIX Specification, Version 3 and as POSIX.1-2001. It was released on January 30, 2002. This SUS consisted of: and is at the core of the UNIX 03 brand. The Base Specifications are technically identical to POSIX.1-2001 , which is IEEE Std 1003.1-2001. This version had 1742 programming interfaces. An authorized guide

629-530: The Open Group to meet the Single UNIX Specification and are allowed to carry the UNIX name. Most such systems are commercial derivatives of the System V code base in one form or another, although Apple macOS 10.5 and later is a BSD variant that has been certified, and EulerOS and Inspur K-UX are Linux distributions that have been certified. A few other systems (such as IBM z/OS) earned the trademark through

666-560: The Single UNIX Specification . A Unix-like application is one that behaves like the corresponding Unix command or shell . Although there are general philosophies for Unix design, there is no technical standard defining the term, and opinions can differ about the degree to which a particular operating system or application is Unix-like. Some well-known examples of Unix-like operating systems include Linux and BSD . These systems are often used on servers as well as on personal computers and other devices. Many popular applications, such as

703-455: The 1980s and 1990s, including 4.4BSD , Linux , and Minix . Some of these have in turn been the basis for commercial "Unix-like" systems, such as BSD/OS and macOS . Several versions of (Mac) OS X/macOS running on Intel-based Mac computers have been certified under the Single UNIX Specification . The BSD variants are descendants of UNIX developed by the University of California at Berkeley, with UNIX source code from Bell Labs . However,

740-542: The BSD code base has evolved since then, replacing all the AT&T code. Since the BSD variants are not certified as compliant with the Single UNIX Specification, they are referred to as "UNIX-like" rather than "UNIX". Dennis Ritchie , one of the original creators of Unix, expressed his opinion that Unix-like systems such as Linux are de facto Unix systems. Eric S. Raymond and Rob Landley have suggested that there are three kinds of Unix-like systems: Those systems with

777-832: The POSIX chair Andrew Josey for the symbolic price of one dollar. There have been some activities to make Linux POSIX-compliant, with Josey having prepared a list of differences between the POSIX standard and the Linux Standard Base specification, but in August 2005, this project was shut down because of missing interest at the LSB work group. Some non-Unix-like operating systems provide a Unix-like compatibility layer , with varying degrees of Unix-like functionality. Other means of Windows-Unix interoperability include: Single UNIX Specification Very few BSD and Linux -based operating systems are submitted for compliance with

SECTION 20

#1732765028257

814-514: The Single UNIX Specification, although system developers generally aim for compliance with POSIX standards, which form the core of the Single UNIX Specification. The latest SUS consists of two parts: the base specifications technically identical to POSIX, and X/Open Curses specification. Some parts of the SUS are optional. The SUS emerged from multiple 1980s efforts to standardize operating system interfaces for software designed for variants of

851-481: The Single UNIX Specification, with the "UNIX" name being used as a certification mark . They do not approve of the construction "Unix-like", and consider it a misuse of their trademark. Their guidelines require "UNIX" to be presented in uppercase or otherwise distinguished from the surrounding text, strongly encourage using it as a branding adjective for a generic word such as "system", and discourage its use in hyphenated phrases. Other parties frequently treat "Unix" as

888-558: The UNIX 95 and UNIX 98 marks. HP-UX 11i V3 Release B.11.31 is registered as UNIX 03 compliant. Previous releases were registered as UNIX 95. Apple macOS (formerly known as Mac OS X and OS X) is registered as UNIX 03 compliant. The first version registered was Mac OS X 10.5 Leopard , certified on October 26, 2007 (on x86 systems). All versions of macOS from Mac OS X Leopard to macOS 10.15 Catalina , except for OS X Lion , have been registered on Intel-based systems, and all versions from macOS 11 Big Sur ,

925-459: The Unix operating system. The need for standardization arose because enterprises using computers wanted to be able to develop programs that could be used on the computer systems of different manufacturers without reimplementing the programs. Unix was selected as the basis for a standard system interface partly because it was manufacturer-neutral. In 1984, the UNIX user group called /usr/group published

962-577: The results of their standardization effort for programming interfaces in their 1984 /usr/group standard, which became basis for what would become the POSIX.1-1988 standard. In 1985, AT&T published System V Interface Definition (SVID), a specification of UNIX System V programming interfaces. In 1988, standardization efforts resulted in IEEE 1003 (also registered as ISO / IEC 9945 ), or POSIX .1-1988 , which loosely stands for Portable Operating System Interface . The X/Open Portability Guide (XPG)

999-813: The standard. It is called PCTS or the POSIX Certification Test Suite . Additionally, SUS includes CURSES (XCURSES) specification, which specifies 372 functions and 3 header files. All in all, SUSv3 specifies 1742 interfaces. Note that a system need not include source code derived in any way from AT&T Unix to meet the specification. For instance, IBM OS/390 , now z/OS , qualifies as UNIX despite having no code in common. There are five official marks for conforming systems: AIX version 7, at either 7.1 TL5 (or later) or 7.2 TL2 (or later) are registered as UNIX 03 compliant. AIX version 7, at 7.2 TL5 (or later) are registered as UNIX V7 compliant. Older versions were previously certified to

1036-508: The status of UNIX as a trademark, but lost his case, and lost again on appeal, with the court upholding the trademark and its ownership. "Unix-like" systems started to appear in the late 1970s and early 1980s. Many proprietary versions, such as Idris (1978), UNOS (1982), Coherent (1983), and UniFlex (1985), aimed to provide businesses with the functionality available to academic users of UNIX. When AT&T allowed relatively inexpensive commercial binary sublicensing of UNIX in 1979,

1073-412: The successor to macOS Catalina, to macOS 14 Sonoma have been registered on both x86-64 and ARM64 systems. UnixWare 7.1.3 and later is registered as UNIX 95 compliant. OpenServer 5 and 6 are registered as UNIX 93 compliant. IBM z/OS 1.2 and higher is registered as UNIX 95 compliant. z/OS 1.9, released on September 28, 2007, and subsequent releases "better align" with UNIX 03. EulerOS 2.0 for

1110-660: Was a precursor to the SUS, published by the X/Open Company , a consortium of companies established in 1984. The guides were published in the following years. XPG4 Base included the following documents: In the early 1990s, a separate effort known as the Common API Specification or Spec 1170 was initiated by several major vendors, who formed the COSE alliance in the wake of the Unix wars . In 1993, Spec 1170

1147-554: Was a repackaging of the X/Open Portability Guide (XPG), Issue 4, Version 2. Sources differ on whether X/Open Curses, Issue 4, Version 2 was part of this SUS; its copyright date is given as 1996. X/Open Curses, Issue 4 was published in 1995. In October 1994, X/Open indicated they were going to refer to Spec 1170 as '"Single-Unix" specification'. The SUS was at the core of the UNIX 95 brand. This version had 1168 programming interfaces. This version of SUS

List of BSD operating systems - Misplaced Pages Continue

1184-669: Was assigned by COSE to X/Open for fasttrack. In October 1993, a planned transfer of UNIX trademark from Novell to X/Open was announced; it was finalized in 2nd quarter of 1994. Spec 1170 would eventually become the Single Unix Specification. In 1994, the X/Open Company released the Single UNIX Specification . The SUS was made up of documents that were part of the X/Open Common Applications Environment (CAE): This

1221-496: Was drawn from the following sources: In 1996, X/Open merged with Open Software Foundation (OSF) to form The Open Group . In 1997, the Open Group released the Single UNIX Specification, Version 2 . This specification consisted of: and was at the core of the UNIX 98 brand. This version had 1434 programming interfaces. Beginning in 1998, a joint working group of IEEE, ISO JTC 1 SC22 and The Open Group known as

1258-416: Was or is replaced. Such an operating system would allow US Department of Defense software, especially for intricate, long-term finance and logistics operations, to be quickly ported to new hardware as it became available. As time went on, code was later ported both from and to Unix System III and still later Unix System V . Unix System V Revision 4 ( SVR4 ), released circa 1992, contained much code which

1295-471: Was ported from BSD version up to and including 4.3BSD. There are various operating systems, particularly GNU / Linux distributions that attempt to imitate the design of BSD, but do not use the code base of any BSD Operating System. Unix-like A Unix-like (sometimes referred to as UN*X or *nix ) operating system is one that behaves in a manner similar to a Unix system, although not necessarily conforming to or being certified to any version of

1332-458: Was published in September 2016, leading into IEEE Std 1003.1-2008, 2016 Edition and Single UNIX Specification, Version 4, 2016 Edition . In January 2018, an "administrative rollup" edition was released. It incorporates Single UNIX Specification version 4 TC1 and TC2, and is technically identical to the 2016 edition. The Base Specifications are technically identical to POSIX.1-2017 , which

1369-490: Was released as 3BSD, and the 4.xBSD series added many new features, including TCP/IP networking. For many years, the primary developer and project leader was Bill Joy , who was a graduate student at the time; funding for this project was provided by DARPA . DARPA was interested in obtaining a programming platform and programmer's interface which would provide a robust, general purpose, time-sharing computing platform which would not become obsolete every time computing hardware

#256743