message: Print error when invalid command is given
diff: @@ -170,7 +170,13 @@ fn cmd(op1: Option<&str>, op2: Option<&str>, proj_opt: &mut Option<RadecoProject
  println!("{} is not found", f);
  }
  }
  - _ => {}
  + _ => {
  + println!(
  + "Invalid command {} {}",
  + op1.unwrap_or(""),
  + op2.unwrap_or("")
  + );
  + }
  }
  }
  