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php通过文件头检测文件类型的自定义类

时间：2021-07-01 10:21:17 帮助过：15人阅读

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

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