Information AboutPosix |
| CATEGORIES ABOUT POSIX | |
| iso standards | |
| ieee standards | |
| unix | |
| application programming interfaces | |
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POSIX is the collective name of a family of related Standard s specified by the IEEE to define the Application Programming Interface (API) for software compatible with variants of the Unix Operating System . They are formally designated as '''IEEE 1003''' and the international standard name is ISO / IEC 9945. The standards emerged from a project, begun circa 1985 . The term ''POSIX'' was suggested by Richard Stallman (not as a compliment) in response to an IEEE request for a memorable name; before that the standards effort was called IEEE-IX. POSIX has been Backronymed to '''Portable Operating System Interface''', with the '''X''' signifying the Unix heritage of the API. OVERVIEW POSIX specifies the user and software interfaces to the OS in some 15 different documents. The standard user command line and scripting interface is commonly implemented with the Korn Shell . Other user-level programs, services and utilities include Awk , Echo , Ed , and hundreds of others. Required program-level services include basic I/O ( File , Terminal , and Network ) services. POSIX also defines a standard Threading library API which is supported by most modern operating systems. According to the earliest published document, ISO/IEC 9945:(various years), the oral pronunciation of POSIX is intended to be /pahz ix/. Currently POSIX documentation is divided in three parts:
A test suite for POSIX accompanies the standard. It is called PCTS or the '''Posix Conformance Test Suite'''. Since the IEEE charges very high rates for POSIX documentation and does not allow on-line publication of the standards, there has been a tendency toward the " Single UNIX Specification " standard, which is open, accepts input from anyone, and is freely available on the Internet . Beginning in 1998 a joint Working Group , the Austin Group , began to develop a combined standard that would be known as the Single UNIX Specification Version 3. Although used mainly for Unix systems, the POSIX standard can apply to any operating system. For example, Windows NT / 2000 complies with POSIX.1, which is good enough for the US government and relatively simple POSIX programs. Many other POSIX programs, however, need more than that and Windows NT / 2000 / XP and later can also be enhanced to include more POSIX compatibility by installing Windows Services For UNIX , which is part of Windows Server 2003 R2 and Windows Vista Enterprise Edition, or Cygwin . The LynxOS Real-time Operating System for embedded applications is also POSIX-conformant. Linux Standard Base is a body which publishes several common extensions and complementary De Facto standards for Linux operating systems (those made of the GNU utilities plus the Linux Kernel ). These are unlikely to be followed by other Unix-like systems which adhere to long established standards, although in many cases the Linux Standard Base itself adheres to those same standards. VERSIONS POSIX has had various "upgrades":
SEE ALSO EXTERNAL LINKS
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