<?php
$lines = file('GeoIPCountryWhois.csv');
$lastIP = 0;
$lastCountry = '';
$fileC = -1;
$data = array();
foreach ($lines as $line_num => $line)
{
    $info = explode(",", $line, 6);
    $iIP = trim($info[2], '"');
    $iC = trim($info[4], '"');
    if(bcdiv($iIP, 100000000, 0) != $fileC)
    {
        $fileC = bcdiv($iIP, 100000000, 0);
        $data[$fileC][$lastIP] = $lastCountry;
    }
    $data[$fileC][$iIP] = strtolower($iC);
    $lastIP = $iIP;
    $lastCountry = strtolower($iC);

}

echo "<pre>".print_r($data, 1)."</pre>";
?>