#include <stdio.h>
#include "EXTERN.h"
#include "perl.h"
#include "XSUB.h"
 
static PerlInterpreter* my_perl;
 
static int my_c_var;
 
static void xs_init(pTHX);
 
extern void boot_DynaLoader(pTHX_ CV* cv);
void boot_Example (pTHX_ CV* cv);
 
static void xs_init(pTHX)
{
    /* set us up for dynamicly loaded modules */
    newXS("DynaLoader::boot_DynaLoader", boot_DynaLoader, __FILE__);
    /* setup our module included in this file */
    newXS("Example::bootstrap", boot_Example, __FILE__);
}
 
static void init_our_modules()
{
    static const char* bootstrap_args[] = { "Example", NULL };
    /* equivilent to bootstrap Example; pretty much */
    call_argv("Example::bootstrap", G_DISCARD, bootstrap_args);
}
 
/* main function. In a library you'd probably use a different
   callback and do this in multiple functions, but I think you
   can get the idea. */
 
int main(int argc, char** argv, char** env) {
    /* same fake args for perl_parse */
    /* we turn on warnings by default here. 'cuz they're good. */
    static const char* perl_argv[] = { "", "-w", "-e", "0" };
 
    my_c_var = 1;
 
    my_perl = perl_alloc();
 
    perl_construct(my_perl);
 
    /* just to initiaize it */
    perl_parse(my_perl, xs_init, 4, perl_argv, NULL);
    /* run END blocks in perl_destruct */
    PL_exit_flags |= PERL_EXIT_DESTRUCT_END;
 
    init_our_modules();
 
    puts("Perl seems to be initialized.\n");
 
    printf("my_c_var = %d\n", my_c_var);
 
    eval_pv(
    /* Hey, perl programs in C code! */
    "use strict;\n"
    "$\\ = qq[\\n];\n"
    "print q[get_my_c_var() = ], Example::get_my_c_var();\n"
    "Example::set_my_c_var(42);\n"
    "print q[get_my_c_var() = ], Example::get_my_c_var();\n"
    , TRUE);
 
    printf("my_c_var = %d\n", my_c_var);
 
    perl_destruct(my_perl);
    perl_free(my_perl);
}
 
/* And some XS code. */
MODULE = Example                PACKAGE = Example
 
int
get_my_c_var()
    CODE:
        RETVAL = my_c_var;
    OUTPUT:
        RETVAL
 
void
set_my_c_var(newval)
        int newval
    CODE:
        my_c_var = newval;