use std::fs::File; use std::io::{self, ErrorKind}; fn main() { match File::open("nonexistent.txt") { Ok(_) => println!("File opened successfully!"), Err(error) => match error.kind() { ErrorKind::NotFound => println!("File not found."), ErrorKind::PermissionDenied => println!("Permission denied."), _ => println!("An unexpected error occurred: {:?}", error), }, } }