Unix-like – Flickroom

evolution of Unix and Unix-like systems, starting in 1969 A Unix-like ( sometimes referred to as UN*X or *nix ) function arrangement is one that behaves in a manner similar to a Unix system, while not necessarily conforming to or being certified to any version of the Single UNIX Specification. A Unix-like lotion is one that behaves like the correspond Unix command or plate. There is no standard for defining the condition, and some remainder of opinion is possible as to the academic degree to which a given function system or application is “ Unix-like ”.

The term can include complimentary and open-source function systems inspired by Bell Labs ‘ Unix or designed to emulate its features, commercial and proprietary work-alikes, and even versions based on the license UNIX source code ( which may be sufficiently “ Unix-like ” to pass certification and bear the “ UNIX ” trademark ) .

definition

The Open Group owns the UNIX trademark and administers the Single UNIX Specification, with the “ UNIX ” name being used as a certification punctuate. They do not approve of the construction “ Unix-like ”, and consider it a pervert of their trademark. Their guidelines require “ UNIX ” to be presented in capital or differently distinguished from the surrounding textbook, strongly encourage using it as a brand adjective for a generic give voice such as “ arrangement ”, and discourage its use in hyphenate phrases. [ 1 ] other parties frequently treat “ Unix ” as a genericized trademark. Some add a wildcard character to the name to make an abbreviation like “ Un*x ” [ 2 ] or “ *nix ”, since Unix-like systems frequently 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 organization names, but are hush by and large recognized to refer to any UNIX system, descendant, or work-alike, even those with wholly unalike names such as Darwin / macOS, illumos / Solaris or FreeBSD. In 2007, Wayne R. Gray sued to dispute the condition of UNIX as a brand, but lost his case, and lost again on appeal, with the court upholding the brand and its ownership. [ 3 ] [ 4 ]

history

Flickroom history of Unix-like operating systems “ 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 academician users of UNIX. When AT & T allowed relatively cheap commercial binary star sub-licensing of UNIX in 1979, a diverseness of proprietorship systems were developed based on it, including AIX, HP-UX, IRIX, SunOS, Tru64, Ultrix, and Xenix. These largely displaced the proprietorship clones. Growing incompatibility among these systems led to the creation of interoperability standards, including POSIX and the Single UNIX Specification. diverse free, low-cost, and unexclusive substitutes for UNIX emerged in the 1980s and 1990s, including 4.4BSD, Linux, and Minix. Some of these have in turn been the footing for commercial “ Unix-like ” systems, such as BSD/OS and macOS. respective versions of ( Mac ) OS X/macOS running on Intel-based Mac computers have been certified under the Single UNIX Specification. [ 5 ] [ 6 ] [ 7 ] [ 8 ] [ 9 ] [ 10 ] [ 11 ] The BSD variants are descendants of UNIX developed by the University of California at Berkeley with UNIX source code from Bell Labs. however, the BSD code basis has evolved since then, replacing all of 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 ” quite than “ UNIX ” .

Categories

Dennis Ritchie, one of the original creators of Unix, expressed his public opinion that Unix-like systems such as Linux are de facto Unix systems. [ 12 ] Eric S. Raymond and Rob Landley have suggested that there are three kinds of Unix-like systems : [ 13 ]

familial UNIX

Those systems with a diachronic connection to the AT & T codebase. Most commercial UNIX systems fall into this class. indeed do the BSD systems, which are descendants of sour 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.

Trademark or branded UNIX

These systems‍—‌largely commercial in nature‍—‌have been determined by 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 root in one human body or another, although Apple macOS 10.5 and later is a BSD form that has been certified, EulerOS and Inspur K-UX are Linux distributions that have been certified, and a few other systems ( such as IBM z/OS ) earned the hallmark through a POSIX compatibility layer and are not otherwise inherently Unix systems. many ancient UNIX systems no long meet this definition .

running UNIX

broadly, any Unix-like arrangement that behaves in a manner approximately coherent with the UNIX specification, including having a “ platform which manages your login and instruction line sessions “ ; [ 14 ] more specifically, this can refer to systems such as Linux or Minix that behave similarly to a UNIX system but have no familial or trademark connection to the AT & T code free-base. Most free/open-source implementations of the UNIX design, whether genetic UNIX or not, fall into the restrict definition of this third category due to the expense of obtaining Open Group documentation, which costs thousands of dollars [ citation needed ] for commercial closed reference systems. Around 2001, Linux was given the opportunity to get a certificate including barren help from the POSIX electric chair Andrew Josey for the emblematic price of one dollar. [ citation needed ] 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 stipulation, [ 15 ] but in August 2005, this project was shut down because of missing interest at the LSB work group. [ citation needed ]

compatibility layers

Some non-Unix-like operational systems provide a Unix-like compatibility layer, with varying degrees of Unix-like functionality .
other means of Windows-Unix interoperability admit :

• The above Windows packages can be used with various X servers for Windows
• Hummingbird Connectivity provides several ways for Windows machines to connect to Unix and Linux machines, from terminal emulators to X clients and servers, and others
• The Windows Resource Kits for versions of Windows NT include a Bourne Shell, some command-line tools, and a version of Perl
• Hamilton C shell is a version of csh written specifically for Windows.

See besides

References