php基于文件头信息检测文件类型的代码

3. //检测文件类型

4. function checkFileType($fileName){
5. $file = fopen($fileName, "rb");
6. $bin = fread($file, 2); //只读2字节
7. fclose($file);
8. // C为无符号整数，网上搜到的都是c，为有符号整数，这样会产生负数判断不正常
9. $strInfo = @unpack("C2chars", $bin);
10. $typeCode = intval($strInfo['chars1'].$strInfo['chars2']);
11. $fileType = '';

12. switch( $typeCode )

13. {
14. case '255216':
15. return $typeCode. ' : ' .'jpg';
16. break;
17. case '7173':
18. return $typeCode. ' : ' .'gif';
19. break;
20. case '13780':
21. return $typeCode. ' : ' .'png';
22. break;
23. case '6677':
24. return $typeCode. ' : ' .'bmp';
25. break;
26. case '7790':
27. return $typeCode. ' : ' .'exe';
28. break;
29. case '7784':
30. return $typeCode. ' : ' .'midi';
31. break;
32. case '8297':
33. return $typeCode. ' : ' .'rar';
34. break;
35. default:
36. return $typeCode. ' : ' .'Unknown';
37. break;
38. }
39. //return $typeCode;
40. }

41. $file_name = '11.doc';

42. echo checkFileType($file_name);
43. ?>

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2、根据php 文件头信息验证文件类型的类

3. /*通过文件名，获得文件类型*

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

90. $filename="22.jpg";

91. echo $filename,"t",cFileTypeCheck::getFileType($filename),"rn";
92. $filename="11.doc";
93. echo $filename,"t",cFileTypeCheck::getFileType($filename),"rn";

94. //也可以这样检测

95. $filename = '22.jpg';
96. $extname = strtolower(substr($filename, strrpos($filename, '.') + 1));
97. echo $extname.'
    ';
98. $file = @fopen($filename, 'rb');
99. if ($file)
100. {
101. $str = @fread($file, 0x400); // 读取前 1024 个字节
102. echo substr($str, 0, 4);
103. @fclose($file);
104. }
105. if (substr($str, 0, 4) == 'MThd' && $extname != 'txt')
106. {
107. $format = 'mid';
108. }
109. elseif (substr($str, 0, 4) == 'RIFF' && $extname == 'wav')
110. {
111. $format = 'wav';
112. }
113. elseif (substr($str ,0, 3) == "/xFF/xD8/xFF")
114. {
115. $format = 'jpg';
116. }
117. elseif (substr($str ,0, 4) == 'GIF8' && $extname != 'txt')
118. {
119. $format = 'gif';
120. }
121. elseif (substr($str ,0, 8 ) == "/x89/x50/x4E/x47/x0D/x0A/x1A/x0A")
122. {
123. $format = 'png';
124. }
125. elseif (substr($str ,0, 2) == 'BM' && $extname != 'txt')
126. {
127. $format = 'bmp';
128. }
129. elseif ((substr($str ,0, 3) == 'CWS' || substr($str ,0, 3) == 'FWS') && $extname != 'txt')
130. {
131. $format = 'swf';
132. }
133. elseif (substr($str ,0, 4) == "/xD0/xCF/x11/xE0")
134. { // D0CF11E == DOCFILE == Microsoft Office Document
135. if (substr($str,0x200,4) == "/xEC/xA5/xC1/x00" || $extname == 'doc')
136. {
137. $format = 'doc';
138. }
139. elseif (substr($str,0x200,2) == "/x09/x08" || $extname == 'xls')
140. {
141. $format = 'xls';
142. } elseif (substr($str,0x200,4) == "/xFD/xFF/xFF/xFF" || $extname == 'ppt')
143. {
144. $format = 'ppt';
145. }
146. } elseif (substr($str ,0, 4) == "PK/x03/x04")
147. {
148. $format = 'zip';
149. } elseif (substr($str ,0, 4) == 'Rar!' && $extname != 'txt')
150. {
151. $format = 'rar';
152. } elseif (substr($str ,0, 4) == "/x25PDF")
153. {
154. $format = 'pdf';
155. } elseif (substr($str ,0, 3) == "/x30/x82/x0A")
156. {
157. $format = 'cert';
158. } elseif (substr($str ,0, 4) == 'ITSF' && $extname != 'txt')
159. {
160. $format = 'chm';
161. } elseif (substr($str ,0, 4) == "/x2ERMF")
162. {
163. $format = 'rm';
164. } elseif ($extname == 'sql')
165. {
166. $format = 'sql';
167. } elseif ($extname == 'txt')
168. {
169. $format = 'txt';
170. }
172. echo $format;
173. ?>

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