Example: COBOL program calling C functions

The following example shows a COBOL program that calls C functions by using the CALL statement.

The example illustrates the following concepts:

 CBL PGMNAME(MIXED)
* This compiler option allows for case-sensitive names for called programs.
*
 IDENTIFICATION DIVISION.
 PROGRAM-ID. "COBCALLC".
*
 DATA DIVISION.
 WORKING-STORAGE SECTION.
 01 N4              PIC 9(4)  COMP-5.
 01 NS4             PIC S9(4) COMP-5.
 01 N9              PIC 9(9)  COMP-5.
 01 NS9             PIC S9(9) COMP-5.
 01 NS18            USAGE COMP-2.
 01 D1              USAGE COMP-2.
 01 D2              USAGE COMP-2.
 01 R1.
     02 NR1         PIC 9(8) COMP-5.
     02 NR2         PIC 9(8) COMP-5.
     02 NR3         PIC 9(8) COMP-5.
 PROCEDURE DIVISION.
     MOVE 123 TO N4
     MOVE -567 TO NS4
     MOVE 98765432 TO N9
     MOVE -13579456 TO NS9
     MOVE 222.22 TO NS18
     DISPLAY "Call MyFun with n4=" N4 " ns4=" NS4 " N9=" n9
     DISPLAY "                ns9="  NS9" ns18="  NS18
* The following CALL illustrates several ways to pass arguments.
*
     CALL "MyFun" USING N4 BY VALUE NS4 BY REFERENCE N9 NS9 NS18
     MOVE 1024 TO N4
* The following CALL returns the C function return value.
*
     CALL "MyFunR" USING BY VALUE N4 RETURNING NS9
     DISPLAY "n4=" N4 " and ns9= n4 times n4= " NS9
     MOVE -357925680.25 TO D1
     CALL "MyFunD" USING BY VALUE D1 RETURNING D2
     DISPLAY "d1=" D1 " and d2= 2.0 times d2= " D2
     MOVE 11111 TO NR1
     MOVE 22222 TO NR2
     MOVE 33333 TO NR3
     CALL "MyFunV" USING R1
     STOP RUN.

related references  
CALL statement (COBOL for AIX Language Reference)