package MyModule;
use vars qw(@ISA $VERSION $CONSTANT_NAME);

BEGIN {
    @ISA = qw(DynaLoader);
    $VERSION = '0.01';

    $CONSTANT_NAME = -1;
}

bootstrap MyModule $VERSION;

##</code><code>##

#include "my_constants.h"

MODULE = MyModule	PACKAGE = MyModule

BOOT:
{
    SV* const_sv = get_sv( "MyModule::CONSTANT_NAME", 0 );
    SvIV_set( const_sv, CONSTANT_VALUE_FROM_C_LIBRARY );
    SvIOK_on( const_sv );
    SvREADONLY_on( const_sv );
}