use rand::Rng; use std::fs::File; use std::io::Write; fn main() { let now_time = chrono::Local::now(); let serial_number = format!( "{}-{}", &now_time.format("%y%m%d%H%M").to_string(), rand::thread_rng().gen_range(100..1000) ); let generated_code = format!(r#"pub const SERIAL_NUMBER: &str = "{}";"#, serial_number); let dest_path = "src/generated_serial_number.rs"; let mut file = File::create(&dest_path).unwrap(); file.write_all(generated_code.as_bytes()).unwrap(); }