Base Definitions (XBD)
XBD is part of the Base Specifications. It provides common definitions for the Base Specifications of the Single UNIX Specification; therefore, readers should be familiar with it before using the other parts. The presence of this volume reduces duplication and ensures consistent use of terminology.
This volume is structured as follows:
Chapter 1: Introduction
Includes the scope of the Base Specifications, normative references, terminology, and portability codes used throughout.
Chapter 2: Conformance
Defines implementation and application conformance, documentation requirements, and definitions for systems with XSI conformance.
Chapter 3: Definitions
Contains the general terms and definitions that apply throughout the Base Specifications.
Chapter 4: General Concepts
Describes general concepts that apply throughout the Base Specifications.
Chapter 5: File Format Notation
Describes the notation used to specify file input and output formats in XBD and XCU.
Chapter 6: Character Set
Describes the portable character set and the process of character set definition.
Chapter 7: Locale
Describes the syntax for defining internationalization locales as well as the POSIX locale provided on all systems.
Chapter 8: Environment Variables
Describes the use of environment variables for internationalization and other purposes.
Chapter 9: Regular Expressions
Describes the syntax for pattern matching using Basic (BREs) and Extended (EREs) Regular Expressions, as used by utilities and functions like regcomp() and regexec().
Chapter 10: Directory Structure and Devices
Describes files and devices found on all systems, such as the infinite data sink and source /dev/null.
Chapter 11: General Terminal Interface
Describes the asynchronous terminal interface for functions in XSH and the stty utility in XCU.
Chapter 12: Utility Conventions
Describes policies for command line arguments, including the utility argument syntax used throughout XCU and guidelines for naming utilities, options, and operands.
Chapter 13: Namespace and Future Directions
Defines the contents of headers needed by programs using the system interfaces defined in XSH. These are in the form of reference pages and are organized alphabetically.
Chapter 14: Headers
Defines the contents of standard C headers (e.g., <stdio.h>, <string.h>) required by programs using the system interfaces defined in XSH.