echo server that tee's output

client.go

package main

import (
	"flag"
	"io"
	"log"
	"net"
	"os"
)

var (
	sock = flag.String("socket", "echo.sock", "socket filename")
)

func init() {
	flag.Parse()
}

func main() {
	c, err := net.Dial("unix", *sock)
	defer c.Close()
	if err != nil {
		log.Fatal(err)
	}

	_, err = io.Copy(c, os.Stdin)
	if err != nil {
		log.Fatal(err)
	}

	io.Copy(os.Stdout, c)
}

server.go

package main

import (
	"bytes"
	"flag"
	"io"
	"log"
	"net"
	"os"
	"os/signal"
	"time"
)

var (
	sock = flag.String("socket", "echo.sock", "socket filename")
)

func init() {
	flag.Parse()
}

func Echo(c net.Conn) {
	var buf bytes.Buffer

	defer c.Close()
	c.SetReadDeadline(time.Now().Add(time.Second / 2))

	io.Copy(&buf, c)
	io.Copy(io.MultiWriter(c, os.Stdout), &buf)
}

func Serve() {
	l, err := net.Listen("unix", *sock)
	if err != nil {
		log.Fatal(err)
	}

	for {
		if c, err := l.Accept(); err == nil {
			go Echo(c)
		}
	}
}

func main() {
	go Serve()
	defer os.Remove(*sock)

	c := make(chan os.Signal, 1)
	signal.Notify(c, os.Interrupt, os.Kill)

	<-c
	return
}