Compaq AAQ2G1FTK 12.7 Calling Non-COBOL Programs from Compaq COBOL

Interprogram Communication
12.6 Calling Compaq COBOL Programs from Other Languages
[3] After calling cobcall again:
================================
retval = 987654321
arg1 = 28
[4] After calling cobcancel:
============================
retval = 987654321
arg1 = 28
+------------------- From COBOL --------------------
| myVal = 0
| arg1 = 28
| arg2 = 2
| arg3 = 3
| arg4 = 4
| retVal = 987654321
+ After ’add arg1 arg2 arg3 arg4 giving arg1 myVal’:
| myVal = 37
| arg1 = 37
| arg2 = 2
| arg3 = 3
| arg4 = 4
| retVal = 987654321
+---------------------------------------------------
[5] After calling cobcall again:
================================
retval = 987654321
arg1 = 37
12.7 Calling Non-COBOL Programs from Compaq COBOL
Because the Compaq COBOL compiler is part of a common language
environment, a Compaq COBOL program can call a procedure written in
another language available in this environment. This communication among
high-level languages exists because these languages adhere to the OpenVMS
Calling Standard or the Compaq Tru64 UNIX Calling Standard for Alpha
Systems, as applicable, when generating a call to a procedure. Section 13.2
brie���y describes the OpenVMS Alpha calling standard.
On OpenVMS, for more information, refer to the material on calling system
routines in the OpenVMS Programming Concepts manual, the OpenVMS RTL
Library (LIB$) Manual, and the OpenVMS System Services Reference Manual.♦
12.7.1 Calling a Fortran Program
Calling a procedure written in Fortran allows you to take advantage of features of
that language. Example 12–12 demonstrates how to call a non-COBOL program
in the run unit.
Example 12–12 Calling a Fortran Program from a COBOL Program
IDENTIFICATION DIVISION.
PROGRAM-ID. GETROOT.
****************************************************
* This program accepts a value from the terminal, *
* calls the Fortran subroutine SQROOT, and passes *
* the value as a character string. Program *
* SQROOT returns the square root of the value. *
****************************************************
(continued on next page)
Interprogram Communication 12–25