package main

import (
	"io"
	"log"
	"net/http"
)

type handler struct{}

func (h *handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
	w.Header().Set("Content-Type", "text/plain")
	io.WriteString(w, "Hello world!")
}

func main() {
	mux := http.NewServeMux()

	mux.Handle("/{$}", &handler{})

	srv := http.Server{
		Addr:    ":8080",
		Handler: mux,
	}

	log.Println("Serving on port 8080...")
	log.Fatal(srv.ListenAndServe())
}