POSIX

The Portable Operating System Interface (POSIX [ pɒzɪks ] ) is a jointly developed by the IEEE and The Open Group Unix standardized Application Programming Interface, which is the interface between application software and the operating system. The international standard is called ISO / IEC / IEEE 9945th

Development

Today's standards are a further development of a project in 1985, the term POSIX was suggested by Richard Stallman in response to the IEEE call for a catchy name. ; previously wore the standard, the designation IEEE -IX. Most Unix systems keep more or less to the in IEEE1003.1 (1990) and IEEE1003.2 (1992 ) set standards. These older versions were replaced in 2001 by the revised version of IEEE Std 1003.1-2001 IEEE and The Open Group. 2004, a slightly revised version of IEEE Std 1003.1, 2004 Edition has been released. The current latest version is the revision of 2008. Possibility to certify a product. Some Linux distributors advertise now to expel a POSIX -compliant operating system.

Specification

The specification of the user and software interface of the operating system is divided into four parts, which together form the standard IEEE Std 1003.1-2008:

The standard POSIX shell is ksh. Other utilities such as awk, vi or echo are also part of the POSIX standard. The C functions shall inter alia provide input or output ( for files, terminals and network services ) are available, along with production and inspection processes, and user and group administration.

POSIX - compliant operating systems

Operating systems can be fully or partially POSIX - compliant - this depends on whether they comply with the POSIX standards completely or only partially. Certified products are mentioned on the POSIX Certification site of IEEE.

Fully POSIX-compliant

The following operating systems are POSIX compliant, they adhere to the entire standard:

  • A / UX
  • AIX
  • Blago
  • BSD / OS
  • Darwin ( Mac OS X)
  • HP- UX
  • INTEGRITY
  • IRIX
  • LynxOS
  • MINIX
  • OpenVMS
  • PenOS
  • QNX
  • RTEMS (POSIX 1003.1-2003 profiles 52)
  • Solaris and OpenSolaris
  • UnixWare
  • VelOSity
  • VxWorks

Largely POSIX-compliant

These operating systems were not officially certified as POSIX - compatible, but stick to the majority of the standards:

  • Nucleus RTOS
  • FreeBSD
  • Linux ( most distributions, see LSB)
  • NetBSD
  • OpenBSD
  • DragonFly BSD
  • PikeOS (real-time operating system for embedded systems with optional PSE51 and PSE52 - partitions )
  • SkyOS
  • SuperUX
  • Syllable
  • VSTa

Compliant by compatibility enhancements

These operating systems are not officially certified as POSIX compliant, but are largely standards-compliant, with the support POSIX compatibility through a kind of extension (usually translation libraries) or an intermediate layer is implemented above the kernel. Without this extension, they are usually not POSIX -compliant.

  • The NT kernel of Microsoft Windows when using the Microsoft Windows Services for UNIX Support of subsets such as Posix threads, for example, by " Pthreads - w32 " allows.
  • ECos - POSIX is part of the standard distribution and is used by many applications.
  • Plan 9: APE - ANSI / POSIX Environment
  • Symbian OS with PIPS (PIPS Is POSIX on Symbian)
  • AmigaOS / MorphOS with ixemul.library
Technical standard International Electrotechnical Commission A/UX IBM AIX BSD/OS Darwin (operating system) BeOS Linux Standard Base Syllable Desktop Plan 9 from Bell Labs History of Unix Native POSIX Thread Library W. Richard Stevens
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