To be honest, I don't have the patience to do this manually, right now. A much more interesting problem would be writing a somewhat generic algorithm to create such regexes. I posted a regex generator for a closely related problem to the fun-with-perl list a while ago. Since adapting it to your question would take more fiddling than I currently have the stamina for, I'll simply outline the structure of the resulting regex (written in /x syntax for the purposes of this post):

0*
    (?:
        1\d?
        |
        2 (?:
            [0-4]\d?
            | 
            5[0-5]?
        )
    )
    (?:
        (?:
            # since we got here, the first 1-3 digits formed a number 
+< 256
            # so allow a dot
            \.
            # a near-copy of the surrounding regex goes here to match 
+next octet
        )
        |
        # no dot matched: allow digit-only strings forming numbers up 
+to 2**32-1
        # (and remember we might already have matched up to 3 digits!)
        # this bit needs adjusting to smaller ranges in the nested cop
+ies
    )

[download]

You can see that it's highly formulaic.

It might make an interesting project to generalize a few numeral-matching pattern builders sufficiently to make them into a module (if such a thing doesn't already exist). I've built such regexen by hand often enough that I've gotten thoroughly sick of doing it; it's a nearly trivial but mind numbingly tedious task.

Makeshifts last the longest.

In reply to Re: (Golf) Expression for matching numeric IP addresses by Aristotle
in thread (Golf) Expression for matching numeric IP addresses by trantor

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