php base64_decode 解码方法

<?php
header('Content-Type:text/html;charset=utf-8');
function encode_file_contents($filename) {
    $type=strtolower(substr(strrchr($filename,'.'),1));
    if('php'==$type && is_file($filename) && is_writable($filename)){// 如果是PHP文件 并且可写 则进行压缩编码
        $contents = file_get_contents($filename);// 判断文件是否已经被编码处理
        $pos = strpos($contents,'powered by arzn QQ:1314778');
        if(false === $pos || $pos>100){ // 去除PHP文件注释和空白，减少文件大小
            $contents = php_strip_whitespace($filename);
            // 去除PHP头部和尾部标识
            $headerPos = strpos($contents,'<?php');
            $footerPos = strrpos($contents,'?>');
            $contents = substr($contents,$headerPos+5,$footerPos-$headerPos);
            $encode = base64_encode(gzdeflate($contents));// 开始编码
            $encode = '<?php'."
 eval(gzinflate(base64_decode("."'".$encode."'".")));

?>";
            return file_put_contents($filename,$encode);
        }
    }
    return false;
}
//调用函数
$filename='1.php';
encode_file_contents($filename);
echo "OK,加密完成！"
?>

以上是加密代码

下面是解密代码

<?php  
        $Code = '这里填写要解密的编码'; // base64编码  
        $File = 'decoded.php';//解码后保存的文件  
        $Temp = base64_decode($Code);  
        $temp = gzinflate($Temp);  
        $FP = fopen($File,"w");  
        fwrite($FP,$temp);  
        fclose($FP);  
        echo "解密成功！";  
?>