}
pub fn get_due(content: &str) -> Result<String, Box<dyn Error>> {
    let fname = content.replace("todo:", "");
    let f = File::open(fname)?;
    let mut reader = BufReader::new(f);
    for line in reader.lines() {
        if let Ok(cont) = line {
            if cont.starts_with("* due:") {
                return Ok(String::from(cont
                                       .trim_start_matches("* due:")
                                       .trim_start()
                                       .trim_end()));
            }
        } else {
            return Err(Box::from("I/O failed"));
        }
    }
    Err(Box::from("tags not found"))

        print!("     ");
        print!("{}", get_due(n)?);