Re^2: regular expression assistance

[chip]

Sadly that pattern misinterprets 100100100100 as a valid IP.

At the very least you'd want to replace \.? with (?:\.|\z) or the like.

[GrandFather]

There are many ways of breaking the pattern. Most of them can't be resolved without knowing the nature of the strings being matched.

The intent was to demonstrate a way of including the range test in the match rather than to strictly match IP number strings and nothing else. So don't be sad, learn from the technique and be happy. ;)