求一个PHP函数 将IP地址进行替换

求一个php函数,将IP地址后两位替换为*.* ,例如将192.168.1.1替换为192.168.*.* !!

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PHP code:
<?php
$input = '192.168.1.1';
$temp = explode('.', $input);
$temp[2] = $temp[3] = '*';
$output = implode('.', $temp);
?>

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PHP code:
<?php
$ip1 = '192.168.1.1';
list($a, $b) = sscanf($ip1, '%d.%d');
echo sprintf('%d.%d.*.*', $a, $b);



?>

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PHP code:
echo preg_replace("/^(\d*)\.(\d*)\..*/",'\1.\2.*.*','192.168.1.1');

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echo preg_replace("/\d+\.\d+$/",'*.*','192.168.1.1');

192.168.*.*

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引用

PHP codeechopreg_replace("/^(\d*)\.(\d*)\..*/",'\1.\2.*.*','192.168.1.1');

good！

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PHP code:
echo preg_replace("/^(\d{1,3})\.(\d{1,3})\..*/",'\1.\2.*.*','192.168.1.1');

是不是更严格些？