IEEE 1003.1, 2004 Edition

Several principles guided the development of this standard: • Application-Oriented The basic goal was to promote portability of application programs across UNIX system environments by developing a clear, consistent, and unambiguous standard for the interface specification of a portable operating system based on the UNIX system documentation. This standard codifies the common, existing definition of the UNIX system. • Interface, Not Implementation This standard defines an interface, not an implementation. No distinction is made between library functions and system calls; both are referred to as functions. No details of the implementation of any function are given (although historical practice is sometimes indicated in the RATIONALE section). Symbolic names are given for constants (such as signals and error numbers) rather than numbers.

Revision Standard - Inactive-Withdrawn. This 2004 Edition includes IEEE Std 1003.1-2001/Cor 1-2002 and IEEE Std 1003.1-2001/Cor 2-2004 incorporated into IEEE Std 1003.1-2001 (the base document). The two Corrigenda address problems discovered since the approval of IEEE Std 1003.1-2001. These changes are mainly due to resolving integration issues raised by the merger of the base documents that were incorporated into IEEE Std 1003.1-2001, which is the single common revision to IEEE Std 1003.1(TM)-1996, IEEE Std 1003.2(TM)-1992, ISO/IEC 9945-1: 1996, ISO/IEC 9945-2: 1993, and the Base Specifications of The Open Group Single UNIX® Specification, Version 2. This standard defines a standard operating system interface and environment, including a command interpreter (or "shell"), and common utility programs to support applications portability at the source code level. This standard is intended to be used by both applications developers and system implementors and comprises four major components (each in an associated volume)