An example of rust ffi to call perl_parse()

main.rs

// cargo run -- -le 'use strict; $x'

use std::ptr;

use std::ffi::CString; // C に渡す文字列
// use std::ffi::CStr; // for C から返された文字列

use std::os::raw::{c_char, c_int /*, c_void*/, c_schar};

enum PerlInterpreter {}
enum XsinitT {}

#[link(name = "perl")]
extern "C" {
    fn perl_alloc() -> *mut PerlInterpreter;
    fn perl_construct(my_perl: *mut PerlInterpreter);
    fn perl_parse(
        my_perl: *mut PerlInterpreter,
        xsinit: *const XsinitT,
        argc: c_int,
        argv: *const *const c_schar,
        env: *const *const c_schar,
    ) -> c_int;
    fn perl_destruct(my_perl: *mut PerlInterpreter) -> c_int;
}

fn main() {
    // https://stackoverflow.com/questions/34379641/how-do-i-convert-rust-args-into-the-argc-and-argv-c-equivalents
    let args = std::env::args().map(|arg| CString::new(arg).unwrap() ).collect::<Vec<CString>>();
    // convert the strings to raw pointers
    let c_args = args.iter().map(|arg| arg.as_ptr()).collect::<Vec<*const c_char>>();

    let my_perl = unsafe {perl_alloc()};
    unsafe {perl_construct(my_perl)};
    // println!("c_args[0] = 0x{:x}\nc_args[1] = 0x{:x}"
    //          , c_args[0] as usize, c_args[1] as usize);
    let _rc = unsafe {
        perl_parse(
            my_perl,
            ptr::null(),
            c_args.len() as c_int,
            c_args.as_ptr(),
            ptr::null()
        );
    };
    
    unsafe {perl_destruct(my_perl)};
}