IO Enums

Enums สำหรับ I/O operations ใน Rust รวมถึง ErrorKind และ SeekFrom ที่ใช้กันบ่อย

1. ErrorKind

ErrorKind enum จำแนกประเภทของ I/O errors ช่วยให้ handle errors แบบ portable ได้

use std::io::{self, ErrorKind};
use std::fs::File;

fn handle_error(err: io::Error) {
    match err.kind() {
        ErrorKind::NotFound => println!("File not found"),
        ErrorKind::PermissionDenied => println!("Permission denied"),
        ErrorKind::AlreadyExists => println!("Already exists"),
        ErrorKind::ConnectionRefused => println!("Connection refused"),
        ErrorKind::ConnectionReset => println!("Connection reset"),
        ErrorKind::NotConnected => println!("Not connected"),
        ErrorKind::AddrInUse => println!("Address in use"),
        ErrorKind::BrokenPipe => println!("Broken pipe"),
        ErrorKind::WouldBlock => println!("Would block"),
        ErrorKind::InvalidInput => println!("Invalid input"),
        ErrorKind::InvalidData => println!("Invalid data"),
        ErrorKind::TimedOut => println!("Timed out"),
        ErrorKind::WriteZero => println!("Write zero"),
        ErrorKind::Interrupted => println!("Interrupted"),
        ErrorKind::UnexpectedEof => println!("Unexpected EOF"),
        _ => println!("Other error: {}", err),
    }
}

fn main() {
    // ============================================
    // Create error from kind
    // ============================================

    let err = io::Error::from(ErrorKind::NotFound);
    handle_error(err);

    // ============================================
    // Try opening non-existent file
    // ============================================

    match File::open("nonexistent.txt") {
        Ok(_) => println!("Opened"),
        Err(e) => handle_error(e),
    }

    // ============================================
    // Custom error with message
    // ============================================

    let custom = io::Error::new(
        ErrorKind::InvalidInput,
        "Custom error message"
    );
    println!("Custom: {}", custom);
}