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

The Standard Map $NCL
Standard and User-Defined Maps
106160 Tandem Computers Incorporated 11–3
The Standard Map
$NCL
The standard map $NCL is used by the FILE and WRITE verbs. Figure 11-1 shows the
structure of the map $NCL. It shows that data structured by this map corresponds to
the following MDO variable:
& stem-name .DATALIST
stem-name
specifies the name of the stem of the MDO variable that holds the record.
Fields in data structured by this map correspond to the following repeated MDO
variables:
…
& stem-name .DATALIST.DATA{1}
& stem-name .DATALIST.DATA{2}
& stem-name .DATALIST.DATA{3}
…
The FILE Verbs and the
Map $NCL
The FILE verbs—FILE ADD, FILE CLOSE, and so on—open and close user databases
(UDBs) and manipulate UDB records. The map $NCL is used to interpret the data in
an MDO variable that contains a record being written to or read from a mapped UDB.
(The FILE GET, FILE OPEN, and FILE PUTGET verbs allow you to use the MAP
operand to specify a different map if you wish, but this is not recommended.)
The FILE verbs are discussed in more detail in Section 12, “Working With Files.”
The WRITE Verb and the
Map $NCL
The WRITE verb uses the map $NCL when sending data between NCL processes in
ordinary variables using either the ARGS or VARS operand. The data is sent as an
enclosed MDO variable, which is mapped by the map $NCL, in a message, which is
mapped by the map $MSG.
This use of the WRITE verb is discussed in Section 16, “Environments and Command
Processing.”