Crate log_reroute[−][src]
Expand description
Crate to reroute logging messages at runtime.
The log logging facade allows to set only a single
destination during the whole lifetime of program. If you want to change the logging destination
multiple times, you can use Reroute (either directly, or through the
init and reroute functions).
This may be useful if you want to log to stderr before you know where the main logs will go.
use fern::Dispatch;
use log::{info, LevelFilter};
fn main() {
// Enable logging of Debug and more severe messages.
log::set_max_level(LevelFilter::Debug);
info!("This log message goes nowhere");
log_reroute::init().unwrap();
info!("Still goes nowhere");
// Log to stderr
let early_logger = Dispatch::new().chain(std::io::stderr()).into_log().1;
log_reroute::reroute_boxed(early_logger);
info!("This one goes to stderr");
// Load file name from config and log to that file
let file = tempfile::tempfile().unwrap();
let logger = Dispatch::new().chain(file).into_log().1;
log_reroute::reroute_boxed(logger);
info!("And this one to the file");
// Stop logging
log_reroute::reroute(log_reroute::Dummy);
}