PHP取二进制文件头判断文件类型

2. /**
3. * PHP取二进制文件头快速判断文件类型
4. *
5. * @param 文件 $file
6. * @return string
7. * @author lrenwang
8. * @blog blog.lrenwang.com
9. */
10. function get_extname($file)
11. {
12. $fp = fopen($file, "rb");
13. $bin = fread($fp, 2); //只读2字节
14. fclose($fp);
15. $bin_info = @unpack("C2chars", $bin);
16. $code = intval($bin_info['chars1'].$bin_info['chars2']);
17. switch ($code) {
18. case 7790:
19. $type = 'exe';
20. break;
21. case 7784:
22. $type = 'midi';
23. break;
24. case 8075:
25. $type = 'zip';
26. break;
27. case 8297:
28. $type = 'rar';
29. break;
30. case 255216:
31. $type = 'jpg';
32. break;
33. case 7173:
34. $type = 'gif';
35. break;
36. case 6677:
37. $type = 'bmp';
38. break;
39. case 13780:
40. $type = 'png';
41. break;
42. default:
43. $type = $code;
44. break;
45. }
46. return $type;
47. }
48. ?>

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