These pass as valid IP addresses: 
10. 22.   109 934324 23832 23.104
200. 12.21.3
0.^^&7".34.55-1

[download]
Try this: 
while ( <DATA> ) {
    chomp;
    print $_, ": ", check_ip( $_ ), "\n";
}


sub check_ip {

    my ( $ip ) = @_;
    return "Wrong format" unless $ip =~ /^(\d{1,3}\.){3}\d{1,3}$/;
    return "Illegal value" if grep { $_ > 255 } split /\./, $ip;
    return "Weird zeroes" if grep { /^0[0-9]/ } split /\./, $ip;
    return "OK"
}

__DATA__
0.^^&7".34.55-1
fda.er32.223.1
10.00.120.13
32.294.233.12
-02.35.54.54
41.41.22.50

[download]

In reply to Re: IP Address Sanity by FamousLongAgo
in thread IP Address Sanity by Anonymous Monk

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