a simple php script to display audit log on a webpage

<?php
require_once ('china-ip-ranges-ipv4.php');

$domains=array();
$log_file = fopen('smartdns/log/audit.log', 'r') or die('Unable to open file!');

while(!feof($log_file)){
        $line=fgets($log_file);
        preg_match("/query (.*?),/", $line, $domain);
        preg_match("/type (\d+),/", $line, $type);
        preg_match("/time (\d+ms),/", $line, $time);
        preg_match("/speed: (-?\d+\.\d+ms),/", $line, $speed);
        preg_match("/group (.*?),/", $line, $group);
        preg_match("/result (.*)/", $line, $result);
        $domains[$domain[1]] = array(
            'type' => $type[1],
            'time' => $time[1],
            'speed' => $speed[1],
            'group' => $group[1],
            'result' => $result[1]
        );
}

$html_table = "<table border='1'>
                <tr>
                  <th>Query</th>
                  <th>Type</th>
                  <th>Time</th>
                  <th>Speed</th>
                  <th>Group</th>
                  <th>Result</th>
                </tr>";

foreach ($domains as $query => $info) {
    $html_table .= "<tr>
                    <td>{$query}</td>
                    <td>{$info['type']}</td>
                    <td>{$info['time']}</td>
                    <td>{$info['speed']}</td>
                    <td>{$info['group']}</td>
                    <td>".ischinaip($info['result'])."</td>
                   </tr>";
}

$html_table .= "</table>";
echo $html_table;

function ischinaip($target){
        global $ip_range;
        $ip=sprintf('%u',ip2long(explode(",", $target)[0]));
        $low=0;
        $high=count($ip_range)-1;
        while ($low<=$high){
                $mid=floor(($low+$high)/2);
                if($ip>=$ip_range[$mid]['left'] && $ip<=$ip_range[$mid]['right']){
                                return '<span style="color:green">'.$target.'</span>';
                }
                if($ip<$ip_range[$mid]['left']){
                        $high=$mid-1;
                }
                if($ip>$ip_range[$mid]['left']){
                        $low=$mid+1;
                }
        }
        return '<span style="color:red">'.$target.'</span>';
}
?>

其中 china-ip-ranges-ipv4.php 为记录了国内 ip （转为数值后）的有序数组，形如

$ip_range=array(
0 =>array("left"=> 16844800, "right"=> 16845055),
1 =>array("left"=> 16909312, "right"=> 16909567),
2 =>array("left"=> 17301760, "right"=> 17302015),
3 =>array("left"=> 17303552, "right"=> 17303807),
4 =>array("left"=> 17563648, "right"=> 17825791),
5 =>array("left"=> 18350080, "right"=> 18874367),