PHP取二进制文件头快速判断文件类型的实现代码

   ‘c:\1.jpg-600’,
        ‘c:\1.png-600’,
        ‘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);
        $str_info  = @unpack(“C2chars”, $bin);
        $type_code = intval($str_info[‘chars1’].$str_info[‘chars2’]);
        $file_type = ”;
        switch ($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;
        }

        echo $file , ‘ type: ‘, $file_type, ‘ code:‘, $type_code, ‘
‘;

    }