silence "no such host" errors

(strings.Contains hack because of https://github.com/golang/go/issues/28635)

1 files changed, 8 insertions, 2 deletions

diff --git a/main.go b/main.go
index 7f9f8b8..af00591 100644
--- a/main.go
+++ b/main.go
@@ -23,14 +23,14 @@ func main() {
 				ip := ipnet.IP
 				for ipnet.Contains(ip) {
 					if names, err := net.LookupAddr(ip.String()); err != nil {
-						fmt.Fprintf(os.Stderr, "%s\t# PTR error: %s\n", ip, err)
+						printErr(ip, "PTR", err)
 					} else {
 						fmt.Printf("%s\t%s\n", ip, strings.Join(names, " "))
 					}
 					if *txt {
 						recs, err := net.LookupTXT(arpa(ip))
 						if err != nil {
-							fmt.Fprintf(os.Stderr, "%s\t# TXT error: %s\n", ip, err)
+							printErr(ip, "TXT", err)
 						} else {
 							for _, rec := range recs {
 								fmt.Printf("%s\tTXT %q\n", ip, rec)
@@ -44,6 +44,12 @@ func main() {
 	}
 }
 
+func printErr(ip net.IP, rrtype string, err error) {
+	if !strings.Contains(err.Error(), "no such host") {
+		fmt.Fprintf(os.Stderr, "%s\t# %s error: %s\n", ip, rrtype, err)
+	}
+}
+
 // arpa returns the .in-addr.arpa or .ip6.arpa name corresponding with the given IP.
 func arpa(ip net.IP) string {
 	if ip4 := ip.To4(); ip4 != nil {