The System V Interface Definition (SVID) is a standard that describes the
AT&T
AT&T Inc. is an American multinational telecommunications holding company headquartered at Whitacre Tower in Downtown Dallas, Texas. It is the world's largest telecommunications company by revenue and the third largest provider of mobile ...
UNIX System V
Unix System V (pronounced: "System Five") is one of the first commercial versions of the Unix operating system. It was originally developed by AT&T and first released in 1983. Four major versions of System V were released, numbered 1, 2, 3, an ...
behavior, including that of
system call
In computing, a system call (commonly abbreviated to syscall) is the programmatic way in which a computer program requests a service from the operating system on which it is executed. This may include hardware-related services (for example, acc ...
s,
C libraries, available programs and devices. While it was not the first attempt at a standardizations document (the industry trade association
/usr/group published a standard in 1984 based on
System III with a few system call additions from
BSD), it was an important effort in early standardization of UNIX in a period when UNIX variants were multiplying rapidly and portability was problematic at best. By 1986, AT&T required conformance with SVID issue 2 if vendors were to actually brand their products "System V R3". By the 1990s, however, its importance was largely eclipsed by
POSIX
The Portable Operating System Interface (POSIX) is a family of standards specified by the IEEE Computer Society for maintaining compatibility between operating systems. POSIX defines both the system- and user-level application programming in ...
and the
Single UNIX Specification, which were based in part upon the SVID. Part of the reason for this was undoubtedly their vendor-independent approach (see
Unix wars
The Unix wars were struggles between vendors to set a standard for the Unix operating system in the late 1980s and early 1990s.
Origins
Although AT&T Corporation created Unix, by the 1980s, the University of California, Berkeley Computer Sy ...
).
Versions of SVID
* Version 1, based on System V Release 2, published Spring, 1985
* Version 2, based on System V Release 3, published 1986 (3 volumes)
* Version 3, based on System V Release 4, published 1989
* Version 4, updated for compliance with
XPG4 X/Open group (also known as the Open Group for Unix Systems and incorporated in 1987 as X/Open Company, Ltd.) was a consortium founded by several European UNIX systems manufacturers in 1984 to identify and promote open standards in the field of i ...
and
POSIX
The Portable Operating System Interface (POSIX) is a family of standards specified by the IEEE Computer Society for maintaining compatibility between operating systems. POSIX defines both the system- and user-level application programming in ...
1003.1-1990, published 1995
See also
*
Intel Binary Compatibility Standard The Intel Binary Compatibility Standard (iBCS) is a standardized application binary interface (ABI) for Unix operating systems on Intel-386-compatible computers, published by AT&T, Intel and SCO in 1988, and updated in 1990. It extends source-lev ...
References
{{reflist
External links
SVID Fourth Editionin
PDF
Portable Document Format (PDF), standardized as ISO 32000, is a file format developed by Adobe in 1992 to present documents, including text formatting and images, in a manner independent of application software, hardware, and operating systems. ...
form
Volume 3Volume 2Volume 1bVolume 1a
Unix standards
UNIX System V