You can simplify the CIDR mask check: 
return unpack ('N', pack ('C4', split /\./, $i) ^ pack ('C4', split /\
+./, $1)) >> 32 - $2;

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   MeowChow                                   
               s aamecha.s a..a\u$&owag.print

In reply to (MeowChow) Re: Check IP with support for CIDR by MeowChow
in thread Check IP with support for CIDR by xaphod

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