vendor/env_logger/examples/default.rs

   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 #[macro_use]
  19 extern crate log;
  20
  21 use env_logger::Env;
  22
  23 fn main() {
  24     // The `Env` lets us tweak what the environment
  25     // variables to read are and what the default
  26     // value is if they're missing
  27     let env = Env::default()
  28         .filter_or("MY_LOG_LEVEL", "trace")
  29         .write_style_or("MY_LOG_STYLE", "always");
  30
  31     env_logger::init_from_env(env);
  32
  33     trace!("some trace log");
  34     debug!("some debug log");
  35     info!("some information log");
  36     warn!("some warning log");
  37     error!("some error log");
  38 }