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

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

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HP COBOL CRE Support

All native programs run in the CRE. Native HP COBOL programs can call and be

called by programs written in native HP C, native HP C++, and pTAL, even if the main

program is not written in HP COBOL.

Topics:

•

Introducing the CRE

•

Shared File Operations

•

Arithmetic Overflow Processing

For more information about writing HP COBOL programs for the CRE, see the CRE

Programmer’s Guide.

Introducing the CRE

The Common Run-Time Environment (CRE) is a set of services that supports mixed-

language programs. The CRE library is a collection of routines that implements the

CRE. The CRE library enables the language-specific run-time libraries to coexist

peacefully with each other. User routines and run-time libraries call CRE library

routines to access shared resources managed by the CRE, such as the standard files

(input, output, and log) and the user heap, regardless of language.

The CRE does not support all possible operations. For example, the CRE supports file

sharing only for the three standard files: standard input, standard output, and standard

log. The language-specific run-time libraries access all other files by calling operating

environment procedures directly, whether or not a program uses the CRE.

Each routine in the program appears to be running in its own language-specific run-

time environment, regardless of the language of the main routine. For example, if the

main routine of a mixed-language program is written in HP COBOL, an HP C routine

has complete access to the HP C run-time library.

Refer to the CRE Programmer’s Guide for more information on writing programs that

use the services provided by the CRE.