Sample ILC applications

Figure 1 and Figure 2 contain an example of an ILC application. The C++ routine CPP1 statically calls the COBOL CBL1 program. CBL1 statically CALLs C++ routine CPP2.

Figure 1. Static call from C++ to COBOL program

 /* Module/File Name: EDCXCB  */
 /******************************************************************/
 /*   Illustration of Interlanguage Communication between C++      */
 /*   and COBOL.  All parameters passed by reference.              */
 /*                                                                */
 /*           CPP1 ---------> CBL1 ---------> CPP2                 */
 /*                 static          static                         */
 /*                  call            call                          */
 /******************************************************************/
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>

 extern "COBOL" {
    void CBL1(short *, long, float, char *);
    void CPP2( int& num, char * newstring);
 }

 /********************* CPP1 routine example ***********************/

 int main()
 {
   signed short int short_int  = 2;
   signed long int  long_int   = 4;
   double           floatpt    = 8.0;
   char             string[80];


   CBL1( &short_int, long_int, floatpt, string );

   fprintf(stderr,"main  ENDED\n");
 }

 void CPP2( int& num, char* newstring)
 {
    fprintf(stderr,"num is %d, newstring is %s\n",num,newstring);
    fprintf(stderr,"CPP2 ended\n");
 }

Figure 2. Static call from COBOL to C++ routine

 *   CBL LIB,QUOTE
 *Module/File Name:  IGZTXCB
 ****************** CBL1 routine example ********************

  IDENTIFICATION DIVISION.
  PROGRAM-ID.  CBL1.

  DATA DIVISION.
  WORKING-STORAGE SECTION.
  77  var1                 PIC S9(9) BINARY VALUE 5.
  01  msg-string           PIC X(80).

  LINKAGE SECTION.
  77  int2                 PIC S9(4) BINARY.
  77  int4                 PIC S9(9) BINARY.
  77  float                COMP-2.
  77  char-string          PIC X(80).

      PROCEDURE DIVISION USING int2 int4 float char-string.

           DISPLAY "CBL1 STARTED".

           IF (int2 NOT = 2) THEN
             DISPLAY "INT2 NOT = 2".

           IF (int4 NOT = 4) THEN
             DISPLAY "INT4 NOT = 4".

           IF (float NOT = 8.0) THEN
             DISPLAY "FLOAT NOT = 8".


    * Place null-character-terminated string in parameter
          STRING "PASSED CHARACTER STRING", X'00' LOW-VALUE
                 DELIMITED BY SIZE INTO msg-string

    * MAKE A STATIC CALL TO C FUNCTION
          CALL "CPP2" USING var1, msg-string.

          DISPLAY "CBL1 ENDED".
          GOBACK.