Matching Simple Data Items

To match simple C external variables or passed data items, you must choose the appropriate USAGE type. For example, to share an integer variable with a C routine, declare it in COBOL as:

77  MY-SHARED-INT  SIGNED-INT, EXTERNAL.

In C, this item is then declared as:

int my_shared_int;

Note:

You must also name my_shared_int in the table of external identifiers, as described in the "direct.c" file.

Here is an example of passing an "int" value in a portable fashion to a C routine:

77  MY-INT   SIGNED-INT.
MOVE 123 TO MY-INT.
CALL "C-ROUTINE" USING, BY VALUE, MY-INT.

The ANSI C routine could then read:

void c_routine( int param1 )
{
 printf( "This should be '123': %d\n", param1 );
}