PHP implementation code for taking binary file header to quickly determine file type_PHP tutorial

$files = array(
'c: 1.jpg',
'c:1.png',
'c:1.gif',
'c:1.rar',
'c:1.zip',
'c:1.exe',
);
foreach ($files AS $file) {
$fp = fopen($file, "rb");
$bin = fread ($fp, 2); //Read only 2 bytes
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';
                                                                                                                5:
$file_type = 'zip';
break;
case 8297:
$file_type = 'rar';
break;
case 255216:
$file_type = 'jpg';
                break; 'gif';
break;
case 6677:
$file_type = 'bmp';
break;
case 13780:
$file_type = 'png';
break ;
default:
$file_type = 'unknown';
break;
}

echo $file , ' type: code:', $type_code, '
';

}


The output result of this example
c:1.jpg type: jpg code:255216
c:1.png type: png code:13780
c:1.gif type : gif code:7173
c:1.rar type: rar code:8297
c:1.zip type: zip code:8075
c:1.exe type: exe code:7790

http://www.bkjia.com/PHPjc/328080.htmlwww.bkjia.comtruehttp: //www.bkjia.com/PHPjc/328080.htmlTechArticleGenerally we judge the file type based on the file extension, but this is very unreliable and can be easily modified The extension is avoided. Generally, the file information must be read to identify it. P...