env_filter/env_filter.rs
1//! Per-target filtering via `EnvFilter` (RUST_LOG-style directives).
2//!
3//! Run with: `cargo run --example env_filter`
4//! Or: `RUST_LOG=trace cargo run --example env_filter`
5
6use tiny_tracing::{Logger, debug, info, trace};
7
8fn main() -> Result<(), Box<dyn std::error::Error>> {
9 let filter = std::env::var("RUST_LOG").unwrap_or_else(|_| "info,env_filter=debug".to_string());
10
11 Logger::new().with_env_filter(filter).init()?;
12
13 info!("info line — always visible");
14 debug!("debug line — visible when this crate is at DEBUG or lower");
15 trace!("trace line — needs RUST_LOG=trace or similar");
16 Ok(())
17}