Providing logging

In a big application, things will sooner or later not go as planned. But that's okay, as long as you have provided a system for your users to know what went wrong and, if possible, why. One time-tested tool to accomplish this is detailed logs that let the user specify for themselves how much diagnosis they want to see.

How to do it...

Follow these steps:

1. Open the Cargo.toml file that has been generated earlier for you.

2. Under[dependencies], add the following line:

log = "0.4.1"
env_logger = "0.5.3"

3. If you want, you can go to log's (https://crates.io/crates/log) or env_logger's (https://crates.io/crates/env_log) crates.io pages to check for the newest version and use that one instead.
4. In the folderbin, create a file calledlogging.rs.

5. Add the following code and run it with RUST_LOG=logging cargo run --bin logging if you're on a Unix-based system. Otherwise, run $env:RUST_LOG="logging"; cargo run --bin logging on Windows:

1   extern crate env_logger;
2   #[macro_use]
3   extern crate...