1 <?php
 2  
 3 /*通过文件名，获得文件类型*
 4  *@author chengmo QQ:8292669*
 5  *@copyright <a href="http://www.cnblogs.com/chengmo">http://www.cnblogs.com/chengmo</a> 2010-10-17
 6  *@version 0.1
 7  *$filename="d:/1.png";echo cFileTypeCheck::getFileType($filename); 打印：png
 8  */
 9 class cFileTypeCheck
10 {
11     private static $_TypeList=array();
12     private static $CheckClass=null;
13     private function __construct($filename)
14     {
15         self::$_TypeList=$this->getTypeList();
16     }
17  
18     /**
19      *处理文件类型映射关系表*
20      *
21      * @param string $filename 文件类型
22      * @return string 文件类型，没有找到返回：other
23      */
24     private function _getFileType($filename)
25     {
26         $filetype="other";
27         if(!file_exists($filename)) throw new Exception("no found file!");
28         $file = @fopen($filename,"rb");
29         if(!$file) throw new Exception("file refuse!");
30         $bin = fread($file, 15); //只读15字节 各个不同文件类型，头信息不一样。
31         fclose($file);
32          
33         $typelist=self::$_TypeList;
34         foreach ($typelist as $v)
35         {
36             $blen=strlen(pack("H*",$v[0])); //得到文件头标记字节数
37             $tbin=substr($bin,0,intval($blen)); ///需要比较文件头长度
38              
39             if(strtolower($v[0])==strtolower(array_shift(unpack("H*",$tbin))))
40             {
41                 return $v[1];
42             }
43         }
44         return $filetype;
45     }
46      
47     /**
48      *得到文件头与文件类型映射表*
49      *
50      * @return array array(array('key',value)...)
51      */
52     public function getTypeList()
53     {
54         return array(array("FFD8FFE1","jpg"),
55         array("89504E47","png"),
56         array("47494638","gif"),
57         array("49492A00","tif"),
58         array("424D","bmp"),
59         array("41433130","dwg"),
60         array("38425053","psd"),
61         array("7B5C727466","rtf"),
62         array("3C3F786D6C","xml"),
63         array("68746D6C3E","html"),
64         array("44656C69766572792D646174","eml"),
65         array("CFAD12FEC5FD746F","dbx"),
66         array("2142444E","pst"),
67         array("D0CF11E0","xls/doc"),
68         array("5374616E64617264204A","mdb"),
69         array("FF575043","wpd"),
70         array("252150532D41646F6265","eps/ps"),
71         array("255044462D312E","pdf"),
72         array("E3828596","pwl"),
73         array("504B0304","zip"),
74         array("52617221","rar"),
75         array("57415645","wav"),
76         array("41564920","avi"),
77         array("2E7261FD","ram"),
78         array("2E524D46","rm"),
79         array("000001BA","mpg"),
80         array("000001B3","mpg"),
81         array("6D6F6F76","mov"),
82         array("3026B2758E66CF11","asf"),
83         array("4D546864","mid"));
84     }
85  
86     public static function   getFileType($filename)
87     {
88         if(!self::$CheckClass) self::$CheckClass=new self($filename);
89         $class=self::$CheckClass;
90         return $class->_getFileType($filename);
91     }
92 }