Historically, C uses a 0 to precede an octal number, 0x to precede a decimal, and 0b for binary. Leading zeroes are otherwise stripped in numerical representation.
Since 0x is not accepted, I'd call it a bug and request that the numbers always get treated as decimal, regardless of leading zeros. There's probably some downstream library making the anachronistic assumption. On Wed, Oct 25, 2017 at 1:45 PM, Max Grobecker < max.grobec...@ml.grobecker.info> wrote: > Hello, > > is there - by standard - a definition on how to represent an IPv4 address? > > I have (for example) the IP address "73.0.255.229", which can IMHO also be > written as "073.000.255.229" as the leading zeroes > are not giving any changes to the binary representation of this address. > Am I right on this? > > But: When I lookup this IP address on https://stat.ripe.net/073.000. > 255.229 the first octet is internally getting swapped to "59". > This can be explained, if you take "073" as an octal value and convert it > to a decimal value. > It is definitely a octal-to-decimal conversion thing, as for example also > the value "010" is getting replaced by "8" and so on. > > Now I'm puzzled: Of course, writing IPv4 octets with leading zeroes is not > very common. > But: Is it officially prohibited or discouraged? > > This weird conversion also happens inside the "geoiplookup" tool by > MaxMind and I'm not sure if I'm going to be the moron in this story > or if I found the same bug inside multiple softwares at once ;-) > > > Thanks and greetings from Wuppertal > Max > >
