I am building a bitcoin clone that needs to be able to connect to other sockets and send information between them. How do I try to connect to another socket and if the socket doesn't respond just continue with the code instead of crashing the whole program?

This is kind of what I think the code would look like:

use std::io::prelude::*;
use std::net::TcpStream;

fn main()
{
    for node in nodes {
        let mut stream = TcpStream::connect(node).unwrap();
        if successful_connection {
            break;
        }
    }
}

CodePudding user response：

The problem is that you use unwrap(). From its docs:

Panics if the value is an Err, with a panic message provided by the Err’s value.

This function's purpose is to abort your program if the operation has failed, and so:

Because this function may panic, its use is generally discouraged. Instead, prefer to use pattern matching and handle the Err case explicitly, or call unwrap_or, unwrap_or_else, or unwrap_or_default.

In case you want to do something only if the operation has succeeded, and do nothing in the other case, if let is your best friend:

if let Ok(stream) = TcpStream::connect(node) {
    // Do something with `stream`
}

If you also want to handle the error case, you can use match:

match TcpStream::connect(node) {
    Ok(stream) => {
        // Do something with `stream`
    }
    Err(error) => {
        // Handle the error
    }
}