working_ruby_to_rust_to_ruby_string.rs

#[no_mangle]
pub extern fn read_json(ro: *const c_char) -> *const c_char {
    let roo = make_string(ro);
    let json_for_rust: HashMap<String, i32> = json::decode(&roo).unwrap();
    let encoded = json::encode(&json_for_rust).unwrap();
    let concated_string = CString::new(encoded).unwrap();
    concated_string.into_raw()
}

fn make_string(s1: *const c_char) -> String {
    let s1_cstr = unsafe { CStr::from_ptr(s1) };
    let s1_and_str = s1_cstr.to_str().unwrap(); 
    let s1_string = s1_and_str.to_string();
    s1_string
}