diff --git a/rpxy-bin/src/log.rs b/rpxy-bin/src/log.rs
index 151c94b..d194eb4 100644
--- a/rpxy-bin/src/log.rs
+++ b/rpxy-bin/src/log.rs
@@ -1,7 +1,7 @@
 use crate::constants::{ACCESS_LOG_FILE, SYSTEM_LOG_FILE};
 use rpxy_lib::log_event_names;
 use std::str::FromStr;
-use tracing_subscriber::{fmt, prelude::*};
+use tracing_subscriber::{filter::filter_fn, fmt, prelude::*};
 
 #[allow(unused)]
 pub use tracing::{debug, error, info, warn};
@@ -12,20 +12,16 @@ pub fn init_logger(log_dir_path: Option<&str>) {
   let level = tracing::Level::from_str(level_string.as_str()).unwrap_or(tracing::Level::INFO);
 
   match log_dir_path {
-    None => {
-      // log to stdout
-      init_stdio_logger(level);
-    }
-    Some(log_dir_path) => {
-      // log to files
-      println!("Activate logging to files: {log_dir_path}");
-      init_file_logger(level, log_dir_path);
-    }
+    // log to stdout
+    None => init_stdio_logger(level),
+    // log to files
+    Some(log_dir_path) => init_file_logger(level, log_dir_path),
   }
 }
 
-/// file logging TODO:
+/// file logging
 fn init_file_logger(level: tracing::Level, log_dir_path: &str) {
+  println!("Activate logging to files: {log_dir_path}");
   let log_dir_path = std::path::PathBuf::from(log_dir_path);
   // create the directory if it does not exist
   if !log_dir_path.exists() {
@@ -63,12 +59,8 @@ fn init_file_logger(level: tracing::Level, log_dir_path: &str) {
   let reg = reg.with(
     system_log_base
       .with_writer(system_log)
-      .with_filter(tracing_subscriber::filter::filter_fn(move |metadata| {
-        (metadata
-          .target()
-          .starts_with(env!("CARGO_PKG_NAME").replace('-', "_").as_str())
-          && metadata.name() != log_event_names::ACCESS_LOG
-          && metadata.level() <= &level)
+      .with_filter(filter_fn(move |metadata| {
+        (is_cargo_pkg(metadata) && metadata.name() != log_event_names::ACCESS_LOG && metadata.level() <= &level)
           || metadata.level() <= &tracing::Level::WARN.min(level)
       })),
   );
@@ -85,12 +77,8 @@ fn init_stdio_logger(level: tracing::Level) {
     let stdio_layer = stdio_layer
       .with_target(false)
       .compact()
-      .with_filter(tracing_subscriber::filter::filter_fn(move |metadata| {
-        (metadata
-          .target()
-          .starts_with(env!("CARGO_PKG_NAME").replace('-', "_").as_str())
-          && metadata.level() <= &level)
-          || metadata.level() <= &tracing::Level::WARN.min(level)
+      .with_filter(filter_fn(move |metadata| {
+        (is_cargo_pkg(metadata) && metadata.level() <= &level) || metadata.level() <= &tracing::Level::WARN.min(level)
       }));
     tracing_subscriber::registry().with(stdio_layer).init();
   } else {
@@ -101,12 +89,8 @@ fn init_stdio_logger(level: tracing::Level) {
       .with_thread_names(true)
       .with_target(true)
       .compact()
-      .with_filter(tracing_subscriber::filter::filter_fn(move |metadata| {
-        (metadata
-          .target()
-          .starts_with(env!("CARGO_PKG_NAME").replace('-', "_").as_str())
-          && metadata.level() <= &level)
-          || metadata.level() <= &tracing::Level::INFO.min(level)
+      .with_filter(filter_fn(move |metadata| {
+        (is_cargo_pkg(metadata) && metadata.level() <= &level) || metadata.level() <= &tracing::Level::INFO.min(level)
       }));
     tracing_subscriber::registry().with(stdio_layer).init();
   };
@@ -116,11 +100,7 @@ fn init_stdio_logger(level: tracing::Level) {
 struct AccessLogFilter;
 impl<S> tracing_subscriber::layer::Filter<S> for AccessLogFilter {
   fn enabled(&self, metadata: &tracing::Metadata<'_>, _: &tracing_subscriber::layer::Context<'_, S>) -> bool {
-    metadata
-      .target()
-      .starts_with(env!("CARGO_PKG_NAME").replace('-', "_").as_str())
-      && metadata.name().contains(log_event_names::ACCESS_LOG)
-      && metadata.level() <= &tracing::Level::INFO
+    is_cargo_pkg(metadata) && metadata.name().contains(log_event_names::ACCESS_LOG) && metadata.level() <= &tracing::Level::INFO
   }
 }
 
@@ -137,3 +117,11 @@ where
     .open(path)
     .expect("Failed to open the log file")
 }
+
+#[inline]
+/// Mached with cargo package name with `_` instead of `-`
+fn is_cargo_pkg(metadata: &tracing::Metadata<'_>) -> bool {
+  metadata
+    .target()
+    .starts_with(env!("CARGO_PKG_NAME").replace('-', "_").as_str())
+}