tquic_tools support writting log to file.

interop/run_endpoint.sh

@@ -59,7 +59,7 @@ COPA)
     ;;
 esac
 
-COMMON_ARGS="--keylog-file $SSLKEYLOGFILE --qlog-dir $QLOG_DIR --log-level TRACE --idle-timeout 30000 --handshake-timeout 30000 --congestion-control-algor $CC_ALGOR"
+COMMON_ARGS="--keylog-file $SSLKEYLOGFILE --qlog-dir $QLOG_DIR --log-level TRACE --log-file $LOG_DIR/$ROLE.log --idle-timeout 30000 --handshake-timeout 30000 --congestion-control-algor $CC_ALGOR"
 
 if [ "$ROLE" == "client" ]; then
     # Wait for the simulator to start up.
@@ -92,15 +92,15 @@ if [ "$ROLE" == "client" ]; then
         CLIENT_ARGS="$CLIENT_ARGS --initial-rtt 100"
         for REQ in $REQUESTS
         do
-            $TQUIC_DIR/$TQUIC_CLIENT $CLIENT_ARGS $REQ >> $LOG_DIR/$ROLE.log 2>&1
+            $TQUIC_DIR/$TQUIC_CLIENT $CLIENT_ARGS $REQ
         done
         ;;
     zerortt)
-        $TQUIC_DIR/$TQUIC_CLIENT $CLIENT_ARGS ${REQS[0]} > $LOG_DIR/$ROLE.log 2>&1
-        $TQUIC_DIR/$TQUIC_CLIENT $CLIENT_ARGS ${REQS[@]:1} >> $LOG_DIR/$ROLE.log 2>&1
+        $TQUIC_DIR/$TQUIC_CLIENT $CLIENT_ARGS ${REQS[0]}
+        $TQUIC_DIR/$TQUIC_CLIENT $CLIENT_ARGS ${REQS[@]:1}
         ;;
     *)
-        $TQUIC_DIR/$TQUIC_CLIENT $CLIENT_ARGS $REQUESTS > $LOG_DIR/$ROLE.log 2>&1
+        $TQUIC_DIR/$TQUIC_CLIENT $CLIENT_ARGS $REQUESTS
         ;;
     esac
 elif [ "$ROLE" == "server" ]; then
@@ -118,5 +118,5 @@ elif [ "$ROLE" == "server" ]; then
     *)
         ;;
     esac
-    $TQUIC_DIR/$TQUIC_SERVER $SERVER_ARGS > $LOG_DIR/$ROLE.log 2>&1
+    $TQUIC_DIR/$TQUIC_SERVER $SERVER_ARGS
 fi

tools/src/bin/tquic_client.rs

@@ -121,6 +121,10 @@ pub struct ClientOpt {
     #[clap(long, default_value = "INFO", value_name = "STR")]
     pub log_level: log::LevelFilter,
 
+    /// Log file path. If no file is specified, logs will be written to `stderr`.
+    #[clap(long, value_name = "FILE")]
+    pub log_file: Option<String>,
+
     /// Override server's address.
     #[clap(short, long, value_name = "ADDR")]
     pub connect_to: Option<SocketAddr>,
@@ -1406,6 +1410,7 @@ fn parse_option() -> std::result::Result<ClientOpt, clap::error::Error> {
 
 fn process_option(option: &mut ClientOpt) -> Result<()> {
     env_logger::builder()
+        .target(tquic_tools::log_target(&option.log_file)?)
         .filter_level(option.log_level)
         .format_timestamp_millis()
         .init();

tools/src/bin/tquic_server.rs

@@ -71,6 +71,10 @@ pub struct ServerOpt {
     #[clap(long, default_value = "INFO")]
     pub log_level: log::LevelFilter,
 
+    /// Log file path. If no file is specified, logs will be written to `stderr`.
+    #[clap(long, value_name = "FILE")]
+    pub log_file: Option<String>,
+
     /// Address to listen.
     #[clap(short, long, default_value = "0.0.0.0:4433", value_name = "ADDR")]
     pub listen: SocketAddr,
@@ -766,6 +770,7 @@ impl TransportHandler for ServerHandler {
 
 fn process_option(option: &mut ServerOpt) -> Result<()> {
     env_logger::builder()
+        .target(tquic_tools::log_target(&option.log_file)?)
         .filter_level(option.log_level)
         .format_timestamp_millis()
         .init();

tools/src/common.rs

@@ -20,7 +20,8 @@ use std::net::SocketAddr;
 
 use clap::builder::PossibleValue;
 use clap::ValueEnum;
-use log::debug;
+use env_logger::Target;
+use log::*;
 use mio::net::UdpSocket;
 use mio::Interest;
 use mio::Registry;
@@ -222,3 +223,19 @@ impl PacketSendHandler for QuicSocket {
         Ok(count)
     }
 }
+
+/// Get the target for the log output.
+pub fn log_target(log_file: &Option<String>) -> Result<Target> {
+    if let Some(log_file) = log_file {
+        if let Ok(file) = std::fs::OpenOptions::new()
+            .create(true)
+            .append(true)
+            .open(log_file)
+        {
+            return Ok(Target::Pipe(Box::new(file)));
+        }
+        return Err(format!("create log file {:?} failed", log_file).into());
+    }
+
+    Ok(Target::Stderr)
+}