package irc import ( "net" "strings" ) func AddrLookupHostname(addr net.Addr) string { addrStr := addr.String() ipaddr, _, err := net.SplitHostPort(addrStr) if err != nil { return addrStr } return LookupHostname(ipaddr) } func LookupHostname(addr string) string { names, err := net.LookupAddr(addr) if err != nil { return addr } return strings.TrimSuffix(names[0], ".") }