测试通过，并写了中文自述文件

client/pong.go

@@ -0,0 +1,30 @@
+package main
+
+import (
+	"fmt"
+	"log"
+	"net"
+)
+
+func main() {
+	sock, err := net.Dial("tcp", ":12345")
+	if err != nil {
+		log.Fatalln("fail to dial ':12345':", err)
+	}
+
+	buffer := make([]byte, 64)
+	for {
+		n, err := sock.Read(buffer)
+		if err != nil {
+			log.Fatalln("fail to read socket:", err)
+		}
+		fmt.Printf(string(buffer))
+		fmt.Printf("[Client] Received %d bytes, '%s'\n", n, string(buffer[:n]))
+		_, err = sock.Write([]byte("pong"))
+		if err != nil {
+			log.Fatalln("fail to write 'pong' to the socket:", err)
+		}
+
+		fmt.Printf("[Client] Sent 'ping'\n")
+	}
+}