if !pathNfilename_abs.is_null() {
    let path = std::path::Path::new(
        std::ffi::CStr::from_ptr(pathNfilename_abs)
            .to_str()
            .unwrap(),
    );
    match fs::canonicalize(path) {
        Ok(v) => {
            return to_cstring(v.to_str().unwrap());
        }
        Err(e) => return 0 as *mut libc::c_char,
    }
} else {
    pathNfilename_abs
}