Golang echo server

echo.go

package main

import (
    "net"
    "io"
    "log"
)

func main() {
    l, err := net.Listen("tcp", "127.0.0.1:9999")
    if err != nil {
        log.Fatal(err)
    }
    defer l.Close()

    for {
        c, err := l.Accept()
        if err != nil {
            log.Print(err)
        }

        go func(c net.Conn) {
            defer c.Close()

            io.Copy(c, c)
        }(c)
    }
}