You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: main.rs
    path of file: ./repos/Theseus/tools/elf_cls/src
    
    the code of the file until where you have to start completion: //! Tool to 
    
fn main() {
    let object_file_extension = OsStr::new("o");

    let mut args = env::args();
    args.next().unwrap();
    let is_x64 = match &args.next().unwrap()[..] {
        "x86_64" => true,
        "aarch64" => false,
        arch => panic!("invalid architecture: {arch}"),
    };
    match &args.next().unwrap()[..] {
        "--file" => {
            let file_path = args.next().unwrap();
            update_file(&file_path, is_x64);
        }
        "--dir" => {
            let directory_path = args.next().expect("no directory path provided");
            for entry in fs::read_dir(directory_path).unwrap() {
                let entry = entry.unwrap();
                let file_path = entry.path();
                if file_path.extension() == Some(object_file_extension) {
                    update_file(&file_path, is_x64);
                }
            }
        }
        option => panic!("invalid option: {option}"),
    }
}