fn escape_string(s: &str) -> String {
    let mut result = String::with_capacity(s.len());
    for c in s.chars() {
        match c {
            '\n' => result.push_str("\\n"),
            '\\' => result.push_str("\\\\"),
            '\"' => result.push_str("\\\""),
            _ => result.push(c),
        }
    }
    return result;
}

            println!("M 644 :{} {}", file_marks[i], &files[i].name);

            println!(
                "M 644 :{} \"{}\"",
                file_marks[i],
                escape_string(&files[i].name)
            );