A demonstration listener in Go

main.go

package main

import (
        "net"
        "fmt"
        "flag"
        "log"
)

var port = flag.Int("port", 1234, "port to listen on")

func main() {
        flag.Parse()

        listener, err := net.ListenTCP("tcp", &net.TCPAddr{
                Port: *port,
        })
        if err != nil {
                log.Fatalf("listen: %s", err)
        }
        defer listener.Close()
        log.Printf("Listening on %s...\n", listener.Addr())

        process := func(conn *net.TCPConn) {
                defer conn.Close()
                log.Printf("Accepted connection: %s <- %s\n", conn.LocalAddr(), conn.RemoteAddr())

                if _, err = fmt.Fprintf(conn, "You connected to: %s\n", conn.LocalAddr()); err != nil {
                        log.Fatalf("fprintf: %s", err)
                }
        }

        for {
                conn, err := listener.AcceptTCP()
                if err != nil {
                        log.Fatalf("accept: %s", err)
                }
                go process(conn)
        }
}

Makefile

include $(GOROOT)/src/Make.inc

TARG=l
DEP=
GOFILES=\
        main.go\

pkgdir=$(GOROOT)/pkg/$(GOOS)_$(GOARCH)
PREREQ+=$(foreach PKG,$(DEP),$(pkgdir)/$(PKG).a)

include $(GOROOT)/src/Make.cmd