Add example client

example_client/go.mod

@@ -0,0 +1,3 @@
+module gosend
+
+go 1.17

example_client/main.go

@@ -0,0 +1,46 @@
+package main
+
+import (
+	"bufio"
+	"encoding/binary"
+	"log"
+	"math"
+	"net"
+	"os"
+)
+
+const remote_addr = "localhost:30501"
+
+func main() {
+	c, err := net.Dial("tcp", remote_addr)
+	if err != nil {
+		log.Panic("Error connecting:", err)
+	}
+	defer c.Close()
+
+	log.Printf("Connected to '%s'. Please input lines\n", remote_addr)
+
+	s := bufio.NewScanner(os.Stdin)
+	for s.Scan() {
+		msg := []byte(s.Text())
+
+		msg_len := len(msg)
+		if msg_len > math.MaxUint32 {
+			log.Println("Message too long")
+			continue
+		}
+
+		len_buf := make([]byte, 4)
+		binary.LittleEndian.PutUint32(len_buf, uint32(msg_len))
+
+		if _, err := c.Write(len_buf); err != nil {
+			log.Panic("Error sending len:", err)
+		}
+		if _, err := c.Write(msg); err != nil {
+			log.Panic("Error sending payload:", err)
+		}
+	}
+	if err := s.Err(); err != nil {
+		log.Println("Error reading:", err)
+	}
+}