Rust 안전한 파일 처리

1use std::fs::{self, File};
2use std::io::{self, BufRead, BufReader, Write};
3use std::path::Path;
4
5fn read_lines<P: AsRef<Path>>(path: P) -> io::Result<Vec<String>> {
6    let file = File::open(path)?;
7    let reader = BufReader::new(file);
8    reader.lines().collect()
9}
10
11fn write_file<P: AsRef<Path>>(path: P, content: &str) -> io::Result<()> {
12    let mut file = File::create(path)?;
13    file.write_all(content.as_bytes())?;
14    Ok(())
15}
16
17fn process_file(input: &str, output: &str) -> Result<(), Box<dyn std::error::Error>> {
18    let lines = read_lines(input)?;
19    let processed: Vec<String> = lines
20        .iter()
21        .filter(|line| !line.trim().is_empty())
22        .map(|line| line.trim().to_uppercase())
23        .collect();
24
25    write_file(output, &processed.join("\n"))?;
26    println!("Processed {} lines", processed.len());
27    Ok(())
28}
29
30fn main() {
31    if let Err(e) = process_file("input.txt", "output.txt") {
32        eprintln!("Error: {}", e);
33        std::process::exit(1);
34    }
35}