PHP code to detect file type based on file header information

//Detect file type
function checkFileType($fileName){
 $file = fopen($fileName, "rb");
 $bin = fread($file , 2); //Only read 2 bytes
 fclose($file);
 // C is an unsigned integer. All those found on the Internet are c, which is a signed integer. This will cause abnormal negative number judgment
 $strInfo = @unpack("C2chars", $bin);
 $typeCode = intval($strInfo['chars1'].$strInfo['chars2']);
 $fileType = '';
< p> switch( $typeCode )
 {
 case '255216':
 return $typeCode. ' : ' .'jpg';
 break;
 case '7173':
 return $typeCode. ' : ' .'gif';
 break;
 case '13780':
 return $typeCode. ' : ' .'png';
 break;
 case '6677':
 return $typeCode. ' : ' .'bmp';
 break;
 case ' 7790':
 return $typeCode. ' : ' .'exe';
 break;
 case '7784':
 return $typeCode. ' : ' .'midi';
 break;
 case '8297':
 return $ typeCode. ' : ' .'rar';
 break;
 default:
 return $typeCode. ' : ' .'Unknown';
 break;
 }
 //return $typeCode;
 }
< ;p>$file_name = '11.doc';
echo checkFileType($file_name);
?>

2. Class to verify file type based on php file header information

/*Get the file type through the file name*
 *$filename="d:/1.png";echo cFileTypeCheck::getFileType($filename); print ：png
 */
class cFileTypeCheck
{
 private static $_TypeList=array();
 private static $CheckClass=null;
 private function __construct($filename)
 {
 self::$_TypeList=$this-> getTypeList();
 }

 /**
 *Processing file type mapping table*
 *
 * @param string $filename file type
 * @return string file type, not found return: other
*/
 private function _getFileType($filename)
 {
 $filetype="other";
 if(!file_exists($filename)) throw new Exception("no found file!");
 $file = @fopen($filename,"rb");
 if(!$file) throw new Exception("file refuse!");
 $bin = fread($file, 15) ; //Read only 15 bytes. Different file types have different header information.
 fclose($file);

 $typelist=self::$_TypeList;
 foreach ($typelist as $v)
 {
 $blen=strlen(pack("H*",$v[0])); //Get the number of bytes marked in the file header
 $tbin=substr($bin,0,intval($blen)); ///Need to compare the length of the file header

 if(strtolower($v[0])==strtolower (array_shift(unpack("H*",$tbin))))
 {
 return $v[1];
 }
 }
 return $filetype;
 }

 /**
 *Get file header and file type mapping table*
 *
 * @return array array(array('key',value)...)
*/
 public function getTypeList()
 {
 return array(array("FFD8FFE1","jpg"),
 array("89504E47","png"),
 array("47494638","gif"),
 array("49492A00" ,"tif"),
 array("424D","bmp"),
 array("41433130","dwg"),
 array("38425053","psd"),
 array("7B5C727466"," rtf"),
 array("3C3F786D6C","xml"),
 array("68746D6C3E","html"),
 array("44656C69766572792D646174","eml"),
 array("CFAD12FEC5FD746F","dbx" ),
 array("2142444E","pst"),
 array("D0CF11E0","xls/doc"),
 array("5374616E64617264204A","mdb"),
 array("FF575043","wpd" ),
 array("252150532D41646F6265","eps/ps"),
 array("255044462D312E","pdf"),
 array("E3828596","pwl"),
 array("504B0304","zip" ),
 array("52617221","rar"),
 array("57415645","wav"),
 array("41564920","avi"),
 array("2E7261FD","ram"),
 array("2E524D46","rm"),
 array("000001BA","mpg"),
 array("000001B3","mpg"),
 array("6D6F6F76","mov"),
 array ("3026B2758E66CF11","asf"),
 array("4D546864","mid"));
 }

 public static function getFileType($filename)
 {
 if(!self::$CheckClass) self:: $CheckClass=new self($filename);
 $class=self::$CheckClass;
 return $class->_getFileType($filename);
 }
}
$filename= "22.jpg";
echo $filename,"t",cFileTypeCheck::getFileType($filename),"rn";
$filename="11.doc";
echo $filename,"t",cFileTypeCheck:: getFileType($filename),"rn";
//It can also be detected like this
$filename = '22.jpg';
$extname = strtolower(substr($filename, strrpos($ filename, '.') + 1));
echo $extname.'';
$file = @fopen($filename, 'rb');
 if ($file)
 {
 $ str = @fread($file, 0x400); // Read the first 1024 bytes
 echo substr($str, 0, 4);
 @fclose($file);
 }
 if (substr($str, 0, 4) == 'MThd' && $extname != 'txt')
 {
 $format = 'mid';
 }
 elseif (substr($str, 0, 4) == 'RIFF' && $extname == 'wav')
 {
 $format = 'wav';
 }
 elseif (substr($str ,0, 3) == "/xFF/xD8/xFF")
 {
 $format = 'jpg' ;
 }
 elseif (substr($str ,0, 4) == 'GIF8' && $extname != 'txt')
 {
 $format = 'gif';
 }
 elseif (substr($str ,0 , 8 ) == "/x89/x50/x4E/x47/x0D/x0A/x1A/x0A")
 {
 $format = 'png';
 }
 elseif (substr($str ,0, 2) == 'BM' && $extname != 'txt')
 {
 $format = 'bmp';
 }
 elseif ((substr($str ,0, 3) == 'CWS' || substr($str ,0 , 3) == 'FWS') && $extname != 'txt')
 {
 $format = 'swf';
 }
 elseif (substr($str ,0, 4) == "/xD0/xCF/ x11/xE0")
 { // D0CF11E == DOCFILE == Microsoft Office Document
 if (substr($str,0x200,4) == "/xEC/xA5/xC1/x00" || $extname == 'doc ')
 {
 $format = 'doc';
 }
 elseif (substr($str,0x200,2) == "/x09/x08" || $extname == 'xls')
 {
 $format = 'xls';
 }elseif (substr($str,0x200,4) == "/xFD/xFF/xFF/xFF" || $extname == 'ppt')
            {
                $format = 'ppt';
            }
        } elseif (substr($str ,0, 4) == "PK/x03/x04")
        {
            $format = 'zip';
        } elseif (substr($str ,0, 4) == 'Rar!' && $extname != 'txt')
        {
            $format = 'rar';
        } elseif (substr($str ,0, 4) == "/x25PDF")
        {
            $format = 'pdf';
        } elseif (substr($str ,0, 3) == "/x30/x82/x0A")
        {
            $format = 'cert';
        } elseif (substr($str ,0, 4) == 'ITSF' && $extname != 'txt')
        {
            $format = 'chm';
        } elseif (substr($str ,0, 4) == "/x2ERMF")
        {
            $format = 'rm';
        } elseif ($extname == 'sql')
        {
            $format = 'sql';
        } elseif ($extname == 'txt')
        {
            $format = 'txt';
        }

echo $format;
?>