NET/MASTER Network Control Language (NCL) Programmer's Guide

Language Elements
NCL Summary
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For example, labels in one procedure or function are visible from another procedure or
function, but it is illegal to invoke a procedure or function with a GOTO or GOSUB
statement because the labels are not in the scope of these core statements. It is illegal
to jump into a DO loop.
For more on the scope of labels, see Section 4, “Initial NCL Procedure Development,”
Section 5, “Controlling Execution Flow,” and Section 6, “Procedures and Functions.”
Scope and Variables
Scope affects variables. Certain types of variables, such as system and global
variables, are visible and accessible from any NCL process. Other variables created by
a procedure or function are local to the procedure or function. Another procedure or
function can use them only if they are explicitly shared to it.
The scope of variables and sharing variables is discussed in more detail in Section 6,
“Procedures and Functions.”
Language Elements This subsection describes the language elements that make up NCL. It defines the
characteristics of core statements and verbs and briefly describes each core statement
and verb. It also summarizes the features of variables, built-in functions, and
expressions.
The complete syntax of every core statement, verb, system variable, and built-in
function is described in the NonStop NET/MASTER NCL Reference Manual.
Core Statements Core statements are regarded as an intrinsic part of NCL. Like verbs, they cause
action to occur but, unlike verbs, they are the only elements of NCL that can change
the structure and flow of an NCL procedure. The selection and repetition of core
statements in an NCL procedure determines the flow of control.
Table 2-5 lists core statements in alphabetic order with a brief description.