IEEE Std 1003.1-2001 is one of a family of standards known as POSIX. The family of standards
extends to many topics; IEEE Std 1003.1-2001 is known as POSIX.1 and consists of both
operating system interfaces and shell and utilities. IEEE Std 1003.1-2001 is technically identical
to The Open Group Base Specifications, Issue 6, which comprise the core volumes of the Single
UNIX Specification, Version 3.
Scope of IEEE Std 1003.1-2001
POSIX.1 and the ISO C Standard
FIPS Requirements
The (paraphrased) goals of this development were to produce a single common revision to the
overlapping POSIX.1 and POSIX.2 standards, and the Single UNIX Specification, Version 2. As
such, the scope of the revision includes the scopes of the original documents merged.
Since the revision includes merging the Base volumes of the Single UNIX Specification, many
features that were previously not ‘‘adopted’’ into earlier revisions of POSIX.1 and POSIX.2 are
now included in IEEE Std 1003.1-2001. In most cases, these additions are part of the XSI
extension; in other cases the standard developers decided that now was the time to migrate
these to the base standard.
The Single UNIX Specification programming environment provides a broad-based functional set
of interfaces to support the porting of existing UNIX applications and the development of new
applications. The environment also supports a rich set of tools for application development.
The majority of the obsolescent material from the existing POSIX.1 and POSIX.2 standards, and
material marked LEGACY from The Open Group’s Base specifications, has been removed in this
revision. New members of the Legacy Option Group have been added, reflecting the advance in
understanding of what is required.
ISO/IEC 9945-4:2003 history
2004ISO/IEC 9945-4:2003/Cor 1:2004 Information technology - Portable Operating System Interface (POSIX) - Part 4: Rationale; Technical Corrigendum 1
2003ISO/IEC 9945-4:2003 Information technology - Portable Operating System Interface (POSIX?) - Part 4: Rationale
2002ISO/IEC 9945-4:2002 Information technology - Portable Operating System Interface (POSIXę) - Part 4: Rationale