func viewHandler(w http.ResponseWriter, r *http.Request) {
    title := r.URL.Path[len("/view/"):]
    p, _ := loadPage(title)
    fmt.Printf(w, "<h1>%s</h1><div>%s</div>", p.Title, p.Body)
}

----

Gives error:

cannot use w (type http.ResponseWriter) as type string in argument to fmt.Printf