stream.rs

use std::io::{self, Read, Write};
use std::fs::File;

fn copy(reader: &mut Read, writer: &mut Write) {
    const BUFFER_SIZE: usize = 32 * 1024;
    let mut buf = [0u8; BUFFER_SIZE];

    while let Ok(n) = reader.read(&mut buf) {
        if n == 0 {
            break;
        }
        let _ = writer.write(&buf[..n]);
    }
}

fn main() {
    let r = io::stdin();
    let mut reader = r.lock();

    let mut writer = File::create("temp.txt").unwrap();

    copy(&mut reader, &mut writer);
}