NET/MASTER Network Control Language (NCL) Reference Manual

Variable Name Syntax
Variables
9–4 106126 Tandem Computers Incorporated
If you refer to a simple variable that has not been assigned a value, NCL returns a null
value denoted by a pair of empty quotation marks (“”).
Complex Variables A complex variable is a variable that contains more than one ampersand. Complex
variables provide the ability to indirectly access data. The term “complex” is used to
describe variables whose names are not known directly. The names must be obtained
by looking up other variables. A complex variable is divided into segments; a segment
is the text between ampersands.
The general form of a complex variable is the following:
& complex [ curly-spec ]
complex
[ nonnumeric-simple ][ &[ middle-segment ] ] …
& last-segment
middle-segment :
nonnumeric-simple
numeric-simple suffix
last-segment :
nonnumeric-simple
numeric-simple [ suffix ]
curly-spec
must be one of the following, enclosed in braces ({ }):
An unsigned number in the range 0 (zero) through 999999.
A variable reference in which the variable contains an unsigned number in the
range 0 (zero) through 999999.
You use curly-spec as an index when you refer to repeated elements in an
MDO variable.
nonnumeric-simple
is a simple variable name that is not numeric (and, therefore, cannot start with a
digit).
numeric-simple
is a simple variable name that is numeric.
suffix
is a constant and can consist of any character in Table 9-1 except the ampersand,
period, opening parenthesis, closing parenthesis, opening brace, or closing brace.