Php code used to read the file header and determine the file type

The following describes how to use php to read the file header and determine the file type. it supports image, rar, exe, and other suffixes, if you need a file, you can refer to the php code below to read the file header to determine the file type, and support suffixes such as images, rar, and exe.
Case:
The code is as follows:
// You can use absolute paths such as d:/upload/11.jpg for the image path.
$ File = fopen ($ filename, "rb ");
$ Bin = fread ($ file, 2); // read-only 2 bytes
Fclose ($ file );
$ StrInfo = @ unpack ("C2chars", $ bin );
$ TypeCode = intval ($ strInfo ['chars1']. $ strInfo ['chars2']);
$ FileType = '';
Switch ($ typeCode ){
Case 7790: $ fileType = 'exe '; break;
Case 7784: $ fileType = 'midi '; break;
Case 8297: $ fileType = 'rar '; break;
Case 255216: $ fileType = 'jpg '; break;
Case 7173: $ fileType = 'GIF'; break;
Case 6677: $ fileType = 'bmp '; break;
Case 13780: $ fileType = 'PNG '; break;
Default: echo 'unknown ';
}
Echo 'this is a'. $ fileType. 'File: '. $ typeCode;

Case:
The code is as follows:
?>
// In linux, php also has a function to determine the file type.
Echo mime_content_type('11.gif '). "\ n ";
Echo mime_content_type ('22. php ');
?>