Preface

This guide is intended for:

This manual is divided into the following sections:

The Endless PL/I for POSIX Systems Reference Manual contains a complete definition of Endless PL/I for POSIX Systems, with detailed reference information on all supported PL/I language elements.

The Endless PL/I for POSIX Systems User's Manual contains information on program development with the system-specific command language, the extensive I/O capabilities provided in PL/I, and programming techniques available to PL/I programs executing under the exclusive control of the operating system.

The manpages contain information on using the pl1 and dbg commands.

The Digital UNIX documentation set gives complete information on the operating system.

For the purposes of this manual, the term PL/I refers to Endless PL/I for POSIX Systems, which runs on Linux, macOS, Tru64 UNIX and other POSIX systems.

All descriptions of the effects of executing statements and evaluating expressions assume that the initial procedure activation of the program is through an entry point with OPTIONS(MAIN).

It is further assumed that any non-PL/I procedures called by the program follow all conventions of the PL/I run-time environment.

Table 1. Documentation Conventions Table

Conventions	Meaning
Return	This symbol represents a single stroke of the RETURN key on the keyboard.
Ctrl+X	This symbol represents a control key combination. The letter X can be any keyboard character. To generate a control key combination, hold down the CTRL key while pressing the specified letter.
command	System text and code in examples and in text appears in the Courier typeface. Since the UNIX operating system differentiates between lowercase and uppercase characters, literal strings in examples and text must be entered exactly as shown.
bold	User input in interactive examples appears in the bold Courier typeface.
bold	Bold words in text indicate the first use of a new term.
italic	File and variable names appear in italics.
	Vertical ellipses indicate that irrelevant parts of the program text or program output have been omitted.
quotation mark apostrophe	The term quotation mark is used only to refer to the double quotation mark character ("). The term apostrophe is used to refer to the single quotation mark character (').
#	A # symbol is used in some contexts to indicate a single ASCII space character.)
pl1(1)	Specifies a manual page. For more information, type: man section page
	This margin icon indicates that the paragraph contains important information to which you should pay close attention.
SYNTAX	Syntax (format) diagrams appear in the Helvetica typeface.
. . .	Horizontal ellipses indicate that additional parameters, options, or values can optionally be entered. When a comma precedes an ellipsis, it indicates that successive items must be separated by commas. Used in syntax diagrams.
[ ]	Square brackets indicate that a syntactic element is optional and you need not specify it. Used in syntax diagrams
[ LIST ] [ EDIT ]	Brackets surrounding two or more stacked items indicate conflicting options, one of which can optionally be chosen. Used in syntax diagrams
{ EXTERNAL } { INTERNAL }	Braces surrounding two or more stacked items indicate conflicting options, one of which must be chosen. Used in syntax diagrams
FILE (file-reference)	An uppercase word or phrase indicates a keyword that must be entered as shown; a lowercase word or phrase indicates an item for which a variable value must be supplied. This convention applies to syntax diagrams, not to code examples.