I'm trying to write a function that tells you if an IP address is in a classless subnet. First of all, has any one already written this code? If not, I'm having trouble with the regex's. Is there an easy way to match a range of numbers like 128-255? I've written it like this, taking advantage of the fact that 255 is the highest possible number: 
if ($number =~ /12[89]/ ||$number =~ /1[3-9]\d/ ||$number =~ /2\d\d\/)
+ 
{
            $match = 1;
}

[download]
There must be a better way.

For the more general subnetting problem I'm thinking I probably need to work in binary and doing the AND's and OR's etc. does anyone know of some example Perl code.

In reply to regex for classless IP subnets by permanentE

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