I very like this approach. It saves us from the "I had aproblem, i used a regex, now i have two problems" situation.
If you (the OP) want a review of most possible implications concerning the parsing of an IP address (numbers from 0 to 255 are an octet of an IP address expressed in the dotted decimal form) you can read some paragraph of "Mastering regular expressions" where the proposed result is: 

      [01]?\d\d?|2[0-4]\d|25[0-5]

[download]
on the same argument you can find interesting an old thread: Don't Use Regular Expressions To Parse IP Addresses! or some exaples on another site.

Regex::Common::net is used for the exact purpose and if you feel strong you can dive in it's source code to see how to match an octet.

L*
There are no rules, there are no thumbs..
Reinvent the wheel, then learn The Wheel; may be one day you reinvent one of THE WHEELS.

In reply to Re^2: Is this a bug in perl regex engine or in my brain? (matching from 0 to 255) by Discipulus
in thread Is this a bug in perl regex engine or in my brain? by nikmit

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