/*文件扩展名说明

  *7173         gif

  *255216       jpg

  *13780        png

  *6677         bmp

  *239187       txt,aspx,asp,sql

  *208207       xls.doc.ppt

  *6063         xml

  *6033         htm,html

  *4742         js

  *8075         xlsx,zip,pptx,mmap,zip

  *8297         rar

  *01           accdb,mdb

  *7790         exe,dll

  *5666         psd

  *255254       rdp

  *10056        bt种子

  *64101        bat

 */

    /*PHP取二进制文件头快速判断文件类型*/

    $files = array(

        'c:\1.jpg',

        'c:\1.png',

        'c:\1.gif',

        'c:\1.rar',

        'c:\1.zip',

        'c:\1.exe',

    );

    foreach ($files AS $file) {

        $fp = fopen($file, "rb");

        $bin = fread($fp, 2); //只读2字节

        fclose($fp);

        // unpack() 函数从二进制字符串对数据进行解包

        $str_info  = @unpack("C2chars", $bin);

        //  intval() 函数用于获取变量的整数值

        $type_code = intval($str_info['chars1'].$str_info['chars2']);

        $file_type = '';

        // 下面将解析后获取的状态值进行判断

        switch ($type_code) {

            case 7790:

                $file_type = 'exe';

                break;

            case 7784:

                $file_type = 'midi';

                break;

            case 8075:

                $file_type = 'zip';

                break;

            case 8297:

                $file_type = 'rar';

                break;

            case 255216:

                $file_type = 'jpg';

                break;

            case 7173:

                $file_type = 'gif';

                break;

            case 6677:

                $file_type = 'bmp';

                break;

            case 13780:

                $file_type = 'png';

                break;

            default:

                $file_type = 'unknown';

                break;

        }

        // 输出文件对应的类型和状态值

        echo $file , ' type: <b>', $file_type, '</b> code:<b>', $type_code, '</b><br />';

    }