Show code lifetime

src/main.rs

@@ -1,7 +1,15 @@
+use std::time::{SystemTime, UNIX_EPOCH};
+
 use base32::Alphabet;
 use clap::Parser;
 use totp_rfc6238::{HashAlgorithm, TotpGenerator};
 
+/// Get the current time since epoch
+pub fn time() -> u64 {
+    SystemTime::now().duration_since(UNIX_EPOCH).unwrap().as_secs()
+}
+
+
 /// TOTP - One Time Password generator
 #[derive(Parser, Debug)]
 #[clap(author, version, about, long_about = None)]
@@ -32,7 +40,10 @@ fn main() {
         Alphabet::RFC4648 { padding: true },
         &args.secret,
     ).unwrap();
+
     let code = totp_generator.get_code(&key);
+    let next_update = totp_generator.get_next_update_time().unwrap();
 
     println!("Secret = {}", code);
+    println!("Next update = {} seconds", next_update - time());
 }