#pragma module	OVERL_TEST  "OVERL_TEST-1-X"

/*
**++
**  FACILITY:  
**
**  MODULE DESCRIPTION:
**
**      This main module which demonstrate using of calling external procedure 
**	from non-resident modules, this mechanizm is provided by LIB$FIND_IMAGE_SYMBOL
**	routine. External module is pointed by OVERL logicals:
**
**	CC  overl_test.c
**	LINK over_test.obj
**	DEFINE/EXEC    OVERL	dev:[dir]OVERL.EXE
**	RUN overl_test.exe
**
**  AUTHORS:
**
**      Ruslan R. Laishev
**
**  CREATION DATE:  3-FEB-2000
**
**--
*/


/*
**
**  INCLUDE FILES
**
*/

#include    <starlet.h>
#include    <lib$routines.h>
#include    <libdef.h>
#include    <descrip.h>



/*
**++
**  FUNCTIONAL DESCRIPTION:
**
**      A main procedure, call LIB$FIND_IMAGE_SYMBOL for find&load external image into
**	a P0 process space, resolving external references, call an external routine.
**
**  FORMAL PARAMETERS:
**
**	None
**
**  RETURN VALUE:
**
**	None
**
**--
*/

#define INIT_SDESC(dsc, len, ptr) {(dsc).dsc$b_dtype = DSC$K_DTYPE_T;\
        (dsc).dsc$b_class = DSC$K_CLASS_S; (dsc).dsc$w_length = (short) (len);\
        (dsc).dsc$a_pointer = (ptr);}


$DESCRIPTOR(overl_file,"OVERL");
$DESCRIPTOR(overl_rtn_sym, "OVERL_RTN");
int (*overl_rtn) (int, struct dsc$descriptor_s *, unsigned short *);

void	main    (void)
{
int status;
char	out_buf [ 128 ];
struct dsc$descriptor_s out_buf_dsc;

    /*
    **++
    ** Find & load external module, resolev external references
    **--
    */
    status = lib$find_image_symbol(&overl_file,&overl_rtn_sym,&overl_rtn,0,0);
    if ( !(1 & status) )
	lib$signal(status);

    /*
    **++
    ** Call overl_rtn () to performs some task
    **--
    */
    INIT_SDESC(out_buf_dsc,sizeof(out_buf),out_buf);

    status = overl_rtn ( 1913, &out_buf_dsc,&out_buf_dsc.dsc$w_length);
    if ( !(1 & status) )
	lib$signal(status);


    /*
    **++
    ** Output result to SYS$OTUPUT
    **--
    */
    status = lib$put_output(&out_buf_dsc);
    if ( !(1 & status) )
	lib$signal(status);
}