IEEE 1003-26-2003 pdf download IEEE Standard for Information Technology— Portable Operating System Interface (POSIX ® ) — Part 26: Device Control Application Program Interface (API) [C Language]
Source,Not Object.Portability
The POSIX standards have been written so that a program written andtranslated for execution on one conforming implementation may also betranslated for execution on another conforming implementation.In thisstandard, source code portability is limited to systems having the samespecial device drivers: but, if that is not the case, use of this standard willenhance portability by making the unportable parts that access specialdevices highly visible and uniformly used. This standard does not guarantee that executable (object or binary) code will execute under a conformingimplementation other than that for which it was translated even if theunderlying hardware is identical
The C Language
This standard is written in terms of the standard C language as specifiedin ISO/IEC 9899:1999111.
No Superuser,No System Administration
There was no intention to specify all aspects of an operating system. System administration facilities and functions are excluded from the POSIXbase standards, and functions usable only by the superuser have not beenincluded. Still,an implementation of the standard interface may alsoimplement features not in the POSIX standards. The POSIX standards arealso not concerned with hardware constraints or system maintenance.
MinimalInterface.Minimally Defined
In keeping with the historical design principles of the UNIX system, themandatory core facilities of the POSIX standards have been kept as minimal as possible.Additional capabilities were added as optional extensionsor separate standards.
Broadly Implementable
The developers of the POSIX standards endeavored to make all specifiedfunctions implementable across a wide range of existing and potential systems,including the following:
(1) All of the current major systems that are ultimately derived fromthe original UNIX system code (Version 7 or later).
(2) Compatible systems that are not derived from the original UNIXsystem code.