COBOL Manual for TNS/E Programs (H06.03+)

Source Program Organization and Format

HP COBOL Manual for TNS/E Programs—520347-003

2-16

Shared Data

Two programs in a run unit can refer to common data in these circumstances:

•

Any program that has described an external data record can refer to the data

content of that record.

•

If program B is contained within program A, both programs can refer to data

possessing the global attribute and described in either:

The containing program A

Any program that directly or indirectly contains A

•

When a program passes a parameter value by reference, this establishes a

common data item—a storage location that each program can access. The called

program can refer to a data item in the calling program, using the same identifier or

a different identifier.

If several programs define a data item as external (causing its storage location to be a

single location outside all programs) and they also define the data item as having a

global name, then all such programs and all programs nested within each of them have

access to the data item.

Example 2-2 is a listing of a set of programs that share data through the global and

external mechanisms. Example 2-3 shows the output produced by executing the

programs.