feat: add fern

__log/fern/src/main.rs

@@ -0,0 +1,25 @@
+#[macro_use] extern crate log;
+
+use log::warn;
+
+fn main() {
+    fern::Dispatch::new()
+    .format(|out, message, record| {
+        out.finish(format_args!(
+            "{}[{}][{}] {}",
+            chrono::Local::now().format("[%Y-%m-%d][%H:%M:%S]"),
+            record.target(),
+            record.level(),
+            message
+        ))
+    })
+    .level(log::LevelFilter::Debug)
+    // .level_for(module, level)
+    .chain(std::io::stdout())
+    .apply().unwrap();
+
+    debug!("Hello, world!");
+    info!("Hello, world!");
+    warn!("Hello, world!");
+    error!("Hello, world!");
+}