考虑以下程序,如何在stdin中检测EOF并打破循环?
use std::io;
use std::process;
fn main() {
let mut sum = 0;
loop {
let mut number_str = String::new();
match io::stdin().read_line(&mut number_str) {
Ok(n) => {},
Err(e) => { println!("ERROR: got '{}' when reading a line", e) }
}
match number_str.trim().parse::<i32>() {
Err(n) => {
println!("ERROR: Entered something that is not a number: '{}'",
number_str.trim_right());
process::exit(1)
},
Ok(n) => { sum += n }
}
}
}
注意:有一个identical question,但答案似乎已经过时了,这就是为什么我在问题标题中添加了一个版本号.
最佳答案 从
documentation for read_line
:
If this reader is currently at EOF then this function will not modify
buf
and will returnOk(n)
wheren
is the number of bytes which were read.