Shell and Utilities (XCU)
XCU1 is part of the Base Specifications. XCU describes the shell and utilities that are available to application programs on systems conformant to this volume of the Single UNIX Specification. Readers are expected to be familiar with the XBD volume.
This volume is structured as follows:
Chapter 1: Introduction
Explains the relationship of XCU to other standards like the ISO C standard and XSH. It also describes utility limits, grammar conventions, defaults, large file support, and requirements for built-in utilities.
Chapter 2: Shell Command Language
Describes the shell command language interpreter and includes alphabetically organized reference pages for the special built-in utilities.
Chapter 3: Utilities
Consists of alphabetically organized reference pages for all utilities other than the special built-in utilities described in Chapter 2.
Footnotes
1. The acronym "XCU" derives from an earlier version of this volume which was called "Commands and Utilities".