**** hfuncs.xs*****
#include "EXTERN.h"
#include "perl.h"
#include "XSUB.h"
#include <stdio.h>
#include <complex.h>
#include <math.h>
#include "ppport.h"


MODULE = hfuncs         PACKAGE = hfuncs

void
for_sub_(int &i,double &x, double &y, int &ny)
        PPCODE:
        for_sub_(&i, &x, y, &ny);


***** test.pl ****
#! /opt/perl5/bin/perl -w
use ExtUtils::testlib;
use ExtUtils::F77;
use hfuncs;
use lib "/usr/lib/perl5/site_perl/5.8.8/ExtUtils/F77";
use lib "/u0/lib/perl5/site_perl/5.8.8/ExtUtils/F77";

        $i=1;
        $ny=3;
        $x = 3.14159;
        @y = (1.1, 2.2, 3.3);
        printf "Perl calling Fortran subroutine, passing\n";
        printf"i= $i, x= $x\n";
        printf"y[] = $y[0], $y[1], $y[2]\n";
        hfuncs::for_sub_(\$i, \$x, \@y, \$ny);