package main import ( "log" "maps" "net/netip" `os` "slices" "github.com/olekukonko/tablewriter" `github.com/olekukonko/tablewriter/tw` ) type ( IpInfo struct { Desc string `r:"-"` IP netip.Addr `r:"-"` Is4 bool Is4In6 bool Is6 bool IsGlobalUnicast bool IsInterfaceLocalMulticast bool IsLinkLocalMulticast bool IsLinkLocalUnicast bool IsLoopback bool IsMulticast bool IsPrivate bool IsUnspecified bool IsValid bool } ) func main() { var err error var s string var idx int var desc string var ip netip.Addr var rows []IpInfo /* var typ reflect.Type var val reflect.Value var fieldVal reflect.Value var field reflect.StructField */ var exampleAddrs map[string]string var tbl *tablewriter.Table = tablewriter.NewTable( os.Stdout, tablewriter.WithBehavior( tw.Behavior{ Structs: tw.Struct{ AutoHeader: tw.On, }, }, ), tablewriter.WithRendition( tw.Rendition{ Settings: tw.Settings{ Separators: tw.Separators{BetweenRows: tw.On}, }, }, ), ) defer func() { var tErr error if tbl != nil { if tErr = tbl.Close(); tErr != nil { log.Printf("Error closing table: %v", tErr) } } }() exampleAddrs = map[string]string{ "IPv4": "203.0.113.10", // RFC 5737 address (https://datatracker.ietf.org/doc/html/rfc5737) "IPv4 Unspecified": "0.0.0.0", "IPv4 Global Unicast": "173.230.132.76", // r00t2.io "IPv4 Multicast (All) (RFC 1112 § 4)": "224.0.0.1", // Should encompass all the multicast below. 224.0.0.0 is reserved. "IPv4 Multicast (Reserved) (RFC 1112 § 4)": "224.0.0.0", // Reserved per RFC but it should still report multicast. "IPv4 Multicast (Link-Local Multicast/Local Network Control Block) (RFC 5771 § 4)": "224.0.0.18", // https://datatracker.ietf.org/doc/html/rfc5771#section-4 (VRRP multicast addr) "IPv4 Multicast (Internetwork Control Block) (RFC 5771 § 5)": "224.0.1.68", // https://datatracker.ietf.org/doc/html/rfc5771#section-5 (mdhcpdiscover, RFC 2730) "IPv4 Multicast (AD-HOC I) (RFC 5771 § 6)": "224.0.2.10", // https://datatracker.ietf.org/doc/html/rfc5771#section-6 "IPv4 Multicast (SDP/SAP) (RFC 5771 § 7)": "224.2.0.10", // https://datatracker.ietf.org/doc/html/rfc5771#section-7 "IPv4 Multicast (AD-HOC II) (RFC 5771 § 6)": "224.3.0.10", // (above) "IPv4 Multicast (Source-Specific) (RFC 5771 § 8)": "232.0.0.10", // https://datatracker.ietf.org/doc/html/rfc5771#section-8 "IPv4 Multicast (GLOP) (RFC 5771 § 9)": "233.0.0.10", // https://datatracker.ietf.org/doc/html/rfc5771#section-9 "IPv4 Multicast (AD-HOC III) (RFC 5771 § 6)": "233.252.0.10", // (above) "IPv4 Multicast (Administrative) (RFC 5771 § 10)": "239.0.0.10", // https://datatracker.ietf.org/doc/html/rfc5771#section-10 "IPv4 Link-Local Unicast (RFC 3927 § 2.1)": "169.254.1.10", // https://datatracker.ietf.org/doc/html/rfc3927#section-2.1 "IPv4 Loopback": "127.0.1.10", // It's actually 127/8. Cannot believe how many people do not know this. "IPv4 Private (RFC 1918)": "10.0.0.10", // https://datatracker.ietf.org/doc/html/rfc1918 "4-in-6 (RFC 4291 § 2.5.5.1)": "::203.0.113.10", // https://datatracker.ietf.org/doc/html/rfc4291#section-2.5.5.1 "4-in-6 (RFC 4291 § 2.5.5.1) (Native)": "::cb00:710a", // "" "4-in-6 (RFC 4291 § 2.5.5.2)": "::ffff:203.0.113.10", // https://datatracker.ietf.org/doc/html/rfc4291#section-2.5.5.2 "4-in-6 (RFC 4291 § 2.5.5.2) (Native)": "::ffff:cb00:710a", // "" "IPv6": "2001:db8::cb00:710a", // RFC 3849 (https://datatracker.ietf.org/doc/html/rfc3849) / RFC 9637 (https://datatracker.ietf.org/doc/html/rfc9637) address "IPv6 Unspecified": "::", "IPv6 Global Unicast": "2600:3c02::f03c:91ff:fe93:c0a7", // r00t2.io "IPv6 Multicast (RFC 4291 § 2.7.1) (Reserved Net)": "ff00::", // https://datatracker.ietf.org/doc/html/rfc4291#section-2.7.1 "IPv6 Multicast (RFC 4291 § 2.7.1) (Reserved)": "ff00::1", // "" "IPv6 Multicast (RFC 4291 § 2.7.1) (All Nodes) (Interface-Local)": "ff01::1", // "" "IPv6 Multicast (RFC 4291 § 2.7.1) (All Nodes) (Link-Local)": "ff02::1", // "" "IPv6 Multicast (RFC 4291 § 2.7.1) (All Routers) (Interface-Local)": "ff01::2", // "" "IPv6 Multicast (RFC 4291 § 2.7.1) (All Routers) (Link-Local)": "ff02::2", // "" "IPv6 Multicast (RFC 4291 § 2.7.1) (All Routers) (Admin-Local)": "ff04::2", // "" "IPv6 Multicast (RFC 4291 § 2.7.1) (All Routers) (Site-Local)": "ff05::2", // "" "IPv6 Multicast (RFC 4291 § 2.7.1) (All Routers) (Org-Local)": "ff08::2", // "" "IPv6 Multicast (RFC 4291 § 2.7.1) (All Routers) (Internet/Global)": "ff0e::2", // "" "IPv6 Multicast (RFC 4291 § 2.7.1) (Solicited Node)": "ff02::1:ff00:10", // "" "IPv6 Link-Local Unicast (RFC 4291 § 2.5.6)": "fe80::cb00:710a", // https://datatracker.ietf.org/doc/html/rfc4291#section-2.5.6 "IPv6 Loopback": "::1", // It's explicitly always a /128 with the address ::1 per RFC 4291 § 2.5.3. "IPv6 Private (Unique-Local Addresses) (RFC 4193) (Reserved)": "fc00::10", // https://datatracker.ietf.org/doc/html/rfc4193 "IPv6 Private (Unique-Local Addresses) (RFC 4193) (Valid)": "fd00::10", // "" } rows = make([]IpInfo, len(exampleAddrs)) for idx, desc = range slices.Sorted(maps.Keys(exampleAddrs)) { s = exampleAddrs[desc] if ip, err = netip.ParseAddr(s); err != nil { log.Panicln(err) } // Currently no way to skip cols etc. https://github.com/olekukonko/tablewriter/issues/317 rows[idx] = IpInfo{ Desc: desc, IP: ip, Is4: ip.Is4(), Is4In6: ip.Is4In6(), Is6: ip.Is6(), IsGlobalUnicast: ip.IsGlobalUnicast(), IsInterfaceLocalMulticast: ip.IsInterfaceLocalMulticast(), IsLinkLocalMulticast: ip.IsLinkLocalMulticast(), IsLinkLocalUnicast: ip.IsLinkLocalUnicast(), IsLoopback: ip.IsLoopback(), IsMulticast: ip.IsMulticast(), IsPrivate: ip.IsPrivate(), IsUnspecified: ip.IsUnspecified(), IsValid: ip.IsValid(), } } if err = tbl.Bulk(rows); err != nil { log.Panicln(err) } if err = tbl.Render(); err != nil { log.Panicln(err) } }