Printing in loop with user input

help
1

Hi all,

I am trying to print something like below,

lispy> hello
No you're a hello
lispy> my name is Dan
No you're a my name is Dan
lispy> Stop being so rude!
No you're a Stop being so rude!
lispy>

taken from here. First I will print lispy> and wait for the user input, then after collecting it, I will print a new line No you are userinput``.

fn main() {
    loop {
        print!("lispy>: ");

        let mut input = String::new();
        match io::stdin().read_line(&mut input) {
            Ok(n) => {
                println!("{} bytes read", n);
                println!("{}", input);
            }
            Err(error) => println!("error: {}", error),
        }
    }
}

This code is not printing the lispy and wainting for the user input. Rather it is printing the whole line including the user input with lispy at once.

Any help.

2

I'd say you need to flush stdout.

3 Likes
3

Here is the updated code,

use std::io::stdout;
use std::io::{self, Write};

fn main() {
    loop {
        print!("lipsy>: ");

        let mut input = String::new();
        match io::stdin().read_line(&mut input) {
            Ok(n) => {
                println!("No you're {}", input);
            }
            Err(error) => println!("error: {}", error),
        }
        stdout().flush().unwrap();
    }
}

I am getting,

     Running `target/debug/lispwithrust`
good
lipsy>: No you're good

bad
lipsy>: No you're bad

nice
lipsy>: No you're nice

But I am expecting it,

lispy> hello
No you're a hello
lispy> my name is Dan
No you're a my name is Dan
lispy> Stop being so rude!
No you're a Stop being so rude!
4

No I meant flush right after print.

2 Likes
5

Thanks by not writing the answer and just telling enough. This helped m learn a bit about flush.

4 Likes
6

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