1 /*!
2 Using `env_logger`.
3 
4 Before running this example, try setting the `MY_LOG_LEVEL` environment variable to `info`:
5 
6 ```no_run,shell
7 $ export MY_LOG_LEVEL='info'
8 ```
9 
10 Also try setting the `MY_LOG_STYLE` environment variable to `never` to disable colors
11 or `auto` to enable them:
12 
13 ```no_run,shell
14 $ export MY_LOG_STYLE=never
15 ```
16 */
17 
18 use log::{debug, error, info, trace, warn};
19 
20 use env_logger::Env;
21 
main()22 fn main() {
23     // The `Env` lets us tweak what the environment
24     // variables to read are and what the default
25     // value is if they're missing
26     let env = Env::default()
27         .filter_or("MY_LOG_LEVEL", "trace")
28         .write_style_or("MY_LOG_STYLE", "always");
29 
30     env_logger::init_from_env(env);
31 
32     trace!("some trace log");
33     debug!("some debug log");
34     info!("some information log");
35     warn!("some warning log");
36     error!("some error log");
37 }
38