1.1

Scope

This part of ISO/IEC 9945 defines a standard operating system interface and environment to support application portability at the source-code level. It is intended to be used by both application developers and system implementors.

This part of ISO/IEC 9945 comprises four major components:

(1) Terminology, concepts, and definitions and specifications that govern structures, headers, environment variables, and related requirements. (2) Definitions for system service interfaces and subroutines. (3) Language-specific system services for the C programming language (4) Interface issues, including portability, error handling, and error recovery.

The following areas are outside the scope of this part of ISO/IEC 9945:

(1) User interface (shell) and associated commands (2) Networking protocols and system call interfaces to those protocols (3) Graphics interfaces (4) Database management system interfaces (5) Record I/O considerations (6) Object or binary code portability (7) System configuration and resource availability (8) The behaviour of system services on systems supporting concurrency within a singe process.

This part of ISO/IEC 9945 describes the external characteristics and facilities that are of importance to applications developers, rather than the internal construction techniques employed to achieve these capabilities. Special emphasis is placed on those functions and facilities that are needed in a wide variety of commercial applications.

This part of ISO/IEC 9945 has been defined exclusively at the source-code level. The objective is that a Strictly Conforming POSIX.1 Application source program can be translated to execute on a co nforming implementation.