php基於文件頭資訊檢測文件類型的程式碼

//偵測檔案類型
function checkFileType($fileName){  $file = fopen( $fileName, "rb");
 $bin = fread($file, 2); //只讀2位元組
 fclose($file);
 // C為無符號整數，網路上搜到的都是c，為有符號整數，這樣會產生負數判斷不正常
 $strInfo = @unpack("C2chars", $bin);
 $typeCode = intval($strInfo['chars1' ].$strInfo['chars2']);
 $fileType = '';
 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
 break
 break
 break
 break
 break
 break
 break
 break
 break ;
 case '7790':
 return $typeCode. ' : ' .'exe';
 break;
 case '7784':
 return $typeCode. ' : ' .'midi ';
 break;
 case '8297':
 return $typeCode. ' : ' .'rar';
 break;
 default:
 return $typeCode. ' : ' .'Unknown';

$file_name = '11.doc';echo checkFileType($file_name);?>

複製程式碼

2、根據php 檔案頭資訊驗證文件類型的類

/*透過檔案名，取得檔案類型*
 *$filename="d:/1. png";echo cFileTypeCheck::getFileType($filename); 列印：png
 */
class cFileTypeCheck
{
 private static $_TypeList=array();
 private static $CheckClass= null;
 private function __construct($filename)
 {
 self::$_TypeList=$this->getTypeList();
 }

 /**
 *處理檔案類型對應關係表*
 *
 * @param string $filename 檔案類型
 * @return string 檔案類型，找不到回傳：other
* /
 private function _getFileType($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); //只讀15位元組各個不同檔案類型，頭資訊不一樣。
 fclose($file);

 $typelist=self::$_TypeList;
 foreach ($typelist as $v)
 {
 $blen=strlen(pack(" H*",$v[0])); //得到檔案頭標記位元組數
 $tbin=substr($bin,0,intval($blen)); ///需要比較檔案頭長度

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

 /**
 *得到文件頭與文件類型映射表*
 *
 * @return array array(array('key',value)...)
*/
 public function getTypeList()
 {
 return array(array. ("FFD8FFE1","jpg"),
 array("89504E47","png"),
 array("47494638","gif"),
 array("49492A00","gif"),
 array("49492A00"" ),
 array("424D","bmp"),
 array("41433130","dwg"),
 array("38425053","psd"),
 array(" 7B5C727466","rtf"),
 array("3C3F786D6C","xml"),
 array("68746D6C3E","html"),
 array("68746D6C3E","html"),
 array("4656C3E","html"),
 array("4656C6"
 array("CFAD12FEC5FD746F","dbx"),
 array("2142444E","pst"),
 array("D0CF11E0","xls/doc"), array("FF575043","wpd"),
 array("252150532D41646F6265","epsm/D50457507575075075003750037500037003750037> "pdf" ),
 array("E3828596","pwl"),
 array("504B0304","zip"),
 array("52617221","rar"),
 array("52617221","rar"),
 array(" 57415645","wav"),
 array("41564920","avi"),
 array("2E7261FD","ram"),
 array("2E524D46,""ram"),
 array("2E524D46,""rm")"
 array("000001BA","mpg"),
 array("000001B3","mpg"),
 array("6D6F6F76","mov"),
 array("6D6F6F76","mov"),
 array("6D6F6F76","mov"),
 array(" ,"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";
//也可以這樣偵測
 $filename = '22.jpg';
$extname = strtolower(substr($filename, strrpos($filename, '.') + 1));
echo $extname.'';
$file = @fopen($filename, 'rb');
 if ($file)
 {
 $str = @fread($file, 0x400); // 讀取前1024位元組
 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;
?>