60 lines
1.3 KiB
Rust
60 lines
1.3 KiB
Rust
/*!
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Using `env_logger` to drive a custom logger.
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Before running this example, try setting the `MY_LOG_LEVEL` environment variable to `info`:
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```no_run,shell
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$ export MY_LOG_LEVEL='info'
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```
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If you only want to change the way logs are formatted, look at the `custom_format` example.
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*/
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use env_logger::filter::{Builder, Filter};
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use log::{info, Log, Metadata, Record, SetLoggerError};
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const FILTER_ENV: &str = "MY_LOG_LEVEL";
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struct MyLogger {
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inner: Filter,
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}
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impl MyLogger {
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fn new() -> MyLogger {
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let mut builder = Builder::from_env(FILTER_ENV);
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MyLogger {
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inner: builder.build(),
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}
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}
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fn init() -> Result<(), SetLoggerError> {
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let logger = Self::new();
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log::set_max_level(logger.inner.filter());
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log::set_boxed_logger(Box::new(logger))
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}
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}
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impl Log for MyLogger {
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fn enabled(&self, metadata: &Metadata) -> bool {
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self.inner.enabled(metadata)
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}
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fn log(&self, record: &Record) {
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// Check if the record is matched by the logger before logging
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if self.inner.matches(record) {
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println!("{} - {}", record.level(), record.args());
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}
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}
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fn flush(&self) {}
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}
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fn main() {
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MyLogger::init().unwrap();
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info!("a log from `MyLogger`");
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}
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