1、mime_content_type()函数判断获取文件类型

mime_content_type返回指定文件的MIME类型，

用法：

1 echomime_content_type('php.gif') ."n";

echomime_content_type('test.php');

输出：

image/gif

text/plain

但是php 5.3.0已经将该函数废弃。如果仍想使用此函数，那么可以对php进行配置启用magic_mime扩展。

2、php Fileinfo 获取文件类型(finfo_open)

PHP官方推荐mime_content_type()的替代函数是Fileinfo函数。PHP 5.3.0+已经默认支持Fileinfo函数(fileinfo support-enabled)，不必进行任何配置即可使用finfo_open()判断获取文件MIME类型。

用法代码如下:

1. $finfo = finfo_open(FILEINFO_MIME);
2. $mimetype = finfo_file($finfo, $filename);
3. finfo_close($finfo);

3、image_type_to_mime_type()获取图片类型

如果需要判断MIME类型的文件只有图像文件，那么首先可以使用exif_imagetype()函数获取图像类型常量，再用image_type_to_mime_type()函数将图像类型常量转换成图片文件的MIME类型。

注意：

需要在php.ini中配置打开php_mbstring.dll (Windows需要)和extension=php_exif.dll。

4、php获取上传文件类型

如果使用php上传文件，检测上传文件的MIME类型，则可以使用全局变量$_FILES['uploadfile']['type']，由客户端的浏览器检测获取文件MIME类型。

下面直接上代码，相信略有些php功底的朋友，读来都不成问题，我实现的是仅支持word和pdf文件，且文件大小小于512kb:

1. $tmpname = $_FILES ['userfile'] ['tmp_name'];
2. if(is_uploaded_file($tmpname)) {
3. $mimetype = detectMIME($tmpname);
4. $tuozhanming = getFileExt($filename, $mimetype);
5. if($tuozhanming == "type_error"){
6. echo '仅支持word和pdf文件，且文件大小小于512kb:<a href='.$reurl.'>请重试</a>';
7. exit();
8. }
9. }else{
10. $_FILES ['userfile'] ['error'] = 6;
11. }
12. if ($_FILES ['userfile'] ['error'] > 0) {
13. echo 'Problem: ';
14. switch ($_FILES ['userfile'] ['error']) {
15. case 1 :
16. echo '上传文件过大:<a href='.$reurl.'>请重试</a>';
17. break;
18. case 2 :
19. echo '上传文件过大:<a href='.$reurl.'>请重试</a>';
20. break;
21. case 3 :
22. echo '文件上传丢失:<a href='.$reurl.'>请重试</a>';
23. break;
24. case 4 :
25. echo '无文件被上传:<a href='.$reurl.'>请重试</a>';
26. break;
27. case 6 :
28. echo '仅支持word和pdf文件，且文件大小小于512kb:<a href='.$reurl.'>请重试</a>';
29. break;
30. case 7 :
31. echo '上传文件存储失败:<a href='.$reurl.'>请重试</a>';
32. break;
33. }
34. exit ();
35. }
36. //判断文件类型
37. //上传文件
38. $_FILES ['userfile'] ['name'] = time () . "." . $tuozhanming;
39. $upfile = '../uploads/' . $_FILES ['userfile'] ['name'];
40. if ( !move_uploaded_file ( $_FILES ['userfile'] ['tmp_name'], $upfile )) {
41. echo 'Problem: 文件移动失败';
42. exit ();
43. }
44. }
45. function detectMIME($filename) {
46. $file = fopen ( $filename, "rb" );
47. $finfo = finfo_open ( FILEINFO_MIME );
48. if (! $finfo) {
49. // 直接读取文件的前4个字节，根据硬编码判断
50. $file = fopen ( $filename, "rb" );
51. $bin = fread ( $file, 4 ); //只读文件头4字节
52. fclose ( $file );
53. $strInfo = @unpack ( "C4chars", $bin );
54. //dechex() 函数把十进制转换为十六进制。
55. $typeCode = dechex ( $strInfo ['chars1'] ) .
56. dechex ( $strInfo ['chars2'] ) .
57. dechex ( $strInfo ['chars3'] ) .
58. dechex ( $strInfo ['chars4'] );
59. $type = '';
60. switch ($typeCode) //硬编码值查表
61. {
62. case "504b34" :
63. $type = 'application/zip; charset=binary';
64. break;
65. case "d0cf11e0" :
66. $type = 'application/vnd.ms-office; charset=binary';
67. break;
68. case "25504446" :
69. $type = 'application/pdf; charset=binary';
70. break;
71. default :
72. $type = 'application/vnd.ms-office; charset=binary';
73. break;
74. }
75. } else {
76. //finfo_file return information of a file
77. $type = finfo_file ( $finfo, $filename );
78. }
79. return $type;
80. function getFileExt($filename, $type) {
81. switch ($type) {
82. case "application/zip; charset=binary" :
83. $extType = "docx";
84. break;
85. case "application/vnd.ms-office; charset=binary" :
86. $extType = "doc";
87. break;
88. case "application/msword; charset=binary" :
89. $extType = "doc";
90. break;
91. case "application/pdf; charset=binary" :
92. $extType = "pdf";
93. break;
94. default :
95. $extType = "type_error";
96. break;
97. }
98. return $extType;
99. }

方法五，网上流传一段PHP读取文件头判断文件类型的方法，有一些bug，经我（54chen）修改实测，应该是这个样子：

1. /**
2. * 读取文件前几个字节 判断文件类型
3. *
4. * @return String
5. */
6. function checkTitle($filename) {
7. $file = fopen($filename, "rb");
8. $bin = fread($file, 2); //只读2字节
9. fclose($file);
10. $strInfo = @unpack("c2chars", $bin);
11. $typeCode = intval($strInfo['chars1'].$strInfo['chars2']);
12. $fileType = '';
13. switch ($typeCode)
14. {
15. case 7790:
16. $fileType = 'exe';
17. break;
18. case 7784:
19. $fileType = 'midi';
20. break;
21. case 8297:
22. $fileType = 'rar';
23. break;
24. case 255216:
25. $fileType = 'jpg';
26. break;
27. case 7173:
28. $fileType = 'gif';
29. break;
30. case 6677:
31. $fileType = 'bmp';
32. break;
33. case 13780:
34. $fileType = 'png';
35. break;
36. default:
37. $fileType = 'unknown'.$typeCode;
38. }
39. //Fix
40. if ($strInfo['chars1']=='-1' && $strInfo['chars2']=='-40' ) {
41. return 'jpg';
42. }
43. if ($strInfo['chars1']=='-119' && $strInfo['chars2']=='80' ) {
44. return 'png';
45. }
46. return $fileType;
47. }

对于上传文件类型的判断，一直没有太好的办法，即使使用上面的代码，也有办法构造假的图片的（如何构造不再传播），有人使用getimagesize来判断，不失为一种好办法：

1. if(in_array($attach['ext'], array('jpg', 'jpeg', 'gif', 'png', 'swf', 'bmp')) && function_exists('getimagesize') && !@getimagesize($target)) {
2. @unlink($target);
3. upload_error('post_attachment_ext_notallowed', $attacharray);
4. }

补充:文件类型 值大全:

1. 123 application/vnd.lotus-1-2-3
2. 3gp video/3gpp
3. aab application/x-authoware-bin
4. aam application/x-authoware-map
5. aas application/x-authoware-seg
6. ai application/postscript
7. aif audio/x-aiff
8. aifc audio/x-aiff
9. aiff audio/x-aiff
10. als audio/X-Alpha5
11. amc application/x-mpeg
12. ani application/octet-stream
13. asc text/plain
14. asd application/astound
15. asf video/x-ms-asf
16. asn application/astound
17. asp application/x-asap
18. asx video/x-ms-asf
19. au audio/basic
20. avb application/octet-stream
21. avi video/x-msvideo
22. awb audio/amr-wb
23. bcpio application/x-bcpio
24. bin application/octet-stream
25. bld application/bld
26. bld2 application/bld2
27. bmp application/x-MS-bmp
28. bpk application/octet-stream
29. bz2 application/x-bzip2
30. cal image/x-cals
31. ccn application/x-cnc
32. cco application/x-cocoa
33. cdf application/x-netcdf
34. cgi magnus-internal/cgi
35. chat application/x-chat
36. class application/octet-stream
37. clp application/x-msclip
38. cmx application/x-cmx
39. co application/x-cult3d-object
40. cod image/cis-cod
41. cpio application/x-cpio
42. cpt application/mac-compactpro
43. crd application/x-mscardfile
44. csh application/x-csh
45. csm chemical/x-csml
46. csml chemical/x-csml
47. css text/css
48. cur application/octet-stream
49. dcm x-lml/x-evm
50. dcr application/x-director
51. dcx image/x-dcx
52. dhtml text/html
53. dir application/x-director
54. dll application/octet-stream
55. dmg application/octet-stream
56. dms application/octet-stream
57. doc application/msword
58. dot application/x-dot
59. dvi application/x-dvi
60. dwf drawing/x-dwf
61. dwg application/x-autocad
62. dxf application/x-autocad
63. dxr application/x-director
64. ebk application/x-expandedbook
65. emb chemical/x-embl-dl-nucleotide
66. embl chemical/x-embl-dl-nucleotide
67. eps application/postscript
68. eri image/x-eri
69. es audio/echospeech
70. esl audio/echospeech
71. etc application/x-earthtime
72. etx text/x-setext
73. evm x-lml/x-evm
74. evy application/x-envoy
75. exe application/octet-stream
76. fh4 image/x-freehand
77. fh5 image/x-freehand
78. fhc image/x-freehand
79. fif image/fif
80. fm application/x-maker
81. fpx image/x-fpx
82. fvi video/isivideo
83. gau chemical/x-gaussian-input
84. gca application/x-gca-compressed
85. gdb x-lml/x-gdb
86. gif image/gif
87. gps application/x-gps
88. gtar application/x-gtar
89. gz application/x-gzip
90. hdf application/x-hdf
91. hdm text/x-hdml
92. hdml text/x-hdml
93. hlp application/winhlp
94. hqx application/mac-binhex40
95. htm text/html
96. html text/html
97. hts text/html
98. ice x-conference/x-cooltalk
99. ico application/octet-stream
100. ief image/ief
101. ifm image/gif
102. ifs image/ifs
103. imy audio/melody
104. ins application/x-NET-Install
105. ips application/x-ipscript
106. ipx application/x-ipix
107. it audio/x-mod
108. itz audio/x-mod
109. ivr i-world/i-vrml
110. j2k image/j2k
111. jad text/vnd.sun.j2me.app-descriptor
112. jam application/x-jam
113. jar application/java-archive
114. jnlp application/x-java-jnlp-file
115. jpe image/jpeg
116. jpeg image/jpeg
117. jpg image/jpeg
118. jpz image/jpeg
119. js application/x-javascript
120. jwc application/jwc
121. kjx application/x-kjx
122. lak x-lml/x-lak
123. latex application/x-latex
124. lcc application/fastman
125. lcl application/x-digitalloca
126. lcr application/x-digitalloca
127. lgh application/lgh
128. lha application/octet-stream
129. lml x-lml/x-lml
130. lmlpack x-lml/x-lmlpack
131. lsf video/x-ms-asf
132. lsx video/x-ms-asf
133. lzh application/x-lzh
134. m13 application/x-msmediaview
135. m14 application/x-msmediaview
136. m15 audio/x-mod
137. m3u audio/x-mpegurl
138. m3url audio/x-mpegurl
139. ma1 audio/ma1
140. ma2 audio/ma2
141. ma3 audio/ma3
142. ma5 audio/ma5
143. man application/x-troff-man
144. map magnus-internal/imagemap
145. mbd application/mbedlet
146. mct application/x-mascot
147. mdb application/x-msaccess
148. mdz audio/x-mod
149. me application/x-troff-me
150. mel text/x-vmel
151. mi application/x-mif
152. mid audio/midi
153. midi audio/midi
154. mif application/x-mif
155. mil image/x-cals
156. mio audio/x-mio
157. mmf application/x-skt-lbs
158. mng video/x-mng
159. mny application/x-msmoney
160. moc application/x-mocha
161. mocha application/x-mocha
162. mod audio/x-mod
163. mof application/x-yumekara
164. mol chemical/x-mdl-molfile
165. mop chemical/x-mopac-input
166. mov video/quicktime
167. movie video/x-sgi-movie
168. mp2 audio/x-mpeg
169. mp3 audio/x-mpeg
170. mp4 video/mp4
171. mpc application/vnd.mpohun.certificate
172. mpe video/mpeg
173. mpeg video/mpeg
174. mpg video/mpeg
175. mpg4 video/mp4
176. mpga audio/mpeg
177. mpn application/vnd.mophun.application
178. mpp application/vnd.ms-project
179. mps application/x-mapserver
180. mrl text/x-mrml
181. mrm application/x-mrm
182. ms application/x-troff-ms
183. mts application/metastream
184. mtx application/metastream
185. mtz application/metastream
186. mzv application/metastream
187. nar application/zip
188. nbmp image/nbmp
189. nc application/x-netcdf
190. ndb x-lml/x-ndb
191. ndwn application/ndwn
192. nif application/x-nif
193. nmz application/x-scream
194. nokia-op-logo image/vnd.nok-oplogo-color
195. npx application/x-netfpx
196. nsnd audio/nsnd
197. nva application/x-neva1
198. oda application/oda
199. oom application/x-AtlasMate-Plugin
200. pac audio/x-pac
201. pae audio/x-epac
202. pan application/x-pan
203. pbm image/x-portable-bitmap
204. pcx image/x-pcx
205. pda image/x-pda
206. pdb chemical/x-pdb
207. pdf application/pdf
208. pfr application/font-tdpfr
209. pgm image/x-portable-graymap
210. pict image/x-pict
211. pm application/x-perl
212. pmd application/x-pmd
213. png image/png
214. pnm image/x-portable-anymap
215. pnz image/png
216. pot application/vnd.ms-powerpoint
217. ppm image/x-portable-pixmap
218. pps application/vnd.ms-powerpoint
219. ppt application/vnd.ms-powerpoint
220. pqf application/x-cprplayer
221. pqi application/cprplayer
222. prc application/x-prc
223. proxy application/x-ns-proxy-autoconfig
224. ps application/postscript
225. ptlk application/listenup
226. pub application/x-mspublisher
227. pvx video/x-pv-pvx
228. qcp audio/vnd.qcelp
229. qt video/quicktime
230. qti image/x-quicktime
231. qtif image/x-quicktime
232. r3t text/vnd.rn-realtext3d
233. ra audio/x-pn-realaudio
234. ram audio/x-pn-realaudio
235. rar application/x-rar-compressed
236. ras image/x-cmu-raster
237. rdf application/rdf+xml
238. rf image/vnd.rn-realflash
239. rgb image/x-rgb
240. rlf application/x-richlink
241. rm audio/x-pn-realaudio
242. rmf audio/x-rmf
243. rmm audio/x-pn-realaudio
244. rmvb audio/x-pn-realaudio
245. rnx application/vnd.rn-realplayer
246. roff application/x-troff
247. rp image/vnd.rn-realpix
248. rpm audio/x-pn-realaudio-plugin
249. rt text/vnd.rn-realtext
250. rte x-lml/x-gps
251. rtf application/rtf
252. rtg application/metastream
253. rtx text/richtext
254. rv video/vnd.rn-realvideo
255. rwc application/x-rogerwilco
256. s3m audio/x-mod
257. s3z audio/x-mod
258. sca application/x-supercard
259. scd application/x-msschedule
260. sdf application/e-score
261. sea application/x-stuffit
262. sgm text/x-sgml
263. sgml text/x-sgml
264. sh application/x-sh
265. shar application/x-shar
266. shtml magnus-internal/parsed-html
267. shw application/presentations
268. si6 image/si6
269. si7 image/vnd.stiwap.sis
270. si9 image/vnd.lgtwap.sis
271. sis application/vnd.symbian.install
272. sit application/x-stuffit
273. skd application/x-Koan
274. skm application/x-Koan
275. skp application/x-Koan
276. skt application/x-Koan
277. slc application/x-salsa
278. smd audio/x-smd
279. smi application/smil
280. smil application/smil
281. smp application/studiom
282. smz audio/x-smd
283. snd audio/basic
284. spc text/x-speech
285. spl application/futuresplash
286. spr application/x-sprite
287. sprite application/x-sprite
288. spt application/x-spt
289. src application/x-wais-source
290. stk application/hyperstudio
291. stm audio/x-mod
292. sv4cpio application/x-sv4cpio
293. sv4crc application/x-sv4crc
294. svf image/vnd
295. svg image/svg-xml
296. svh image/svh
297. svr x-world/x-svr
298. swf application/x-shockwave-flash
299. swfl application/x-shockwave-flash
300. t application/x-troff
301. tad application/octet-stream
302. talk text/x-speech
303. tar application/x-tar
304. taz application/x-tar
305. tbp application/x-timbuktu
306. tbt application/x-timbuktu
307. tcl application/x-tcl
308. tex application/x-tex
309. texi application/x-texinfo
310. texinfo application/x-texinfo
311. tgz application/x-tar
312. thm application/vnd.eri.thm
313. tif image/tiff
314. tiff image/tiff
315. tki application/x-tkined
316. tkined application/x-tkined
317. toc application/toc
318. toy image/toy
319. tr application/x-troff
320. trk x-lml/x-gps
321. trm application/x-msterminal
322. tsi audio/tsplayer
323. tsp application/dsptype
324. tsv text/tab-separated-values
325. tsv text/tab-separated-values
326. ttf application/octet-stream
327. ttz application/t-time
328. txt text/plain
329. ult audio/x-mod
330. ustar application/x-ustar
331. uu application/x-uuencode
332. uue application/x-uuencode
333. vcd application/x-cdlink
334. vcf text/x-vcard
335. vdo video/vdo
336. vib audio/vib
337. viv video/vivo
338. vivo video/vivo
339. vmd application/vocaltec-media-desc
340. vmf application/vocaltec-media-file
341. vmi application/x-dreamcast-vms-info
342. vms application/x-dreamcast-vms
343. vox audio/voxware
344. vqe audio/x-twinvq-plugin
345. vqf audio/x-twinvq
346. vql audio/x-twinvq
347. vre x-world/x-vream
348. vrml x-world/x-vrml
349. vrt x-world/x-vrt
350. vrw x-world/x-vream
351. vts workbook/formulaone
352. wav audio/x-wav
353. wax audio/x-ms-wax
354. wbmp image/vnd.wap.wbmp
355. web application/vnd.xara
356. wi image/wavelet
357. wis application/x-InstallShield
358. wm video/x-ms-wm
359. wma audio/x-ms-wma
360. wmd application/x-ms-wmd
361. wmf application/x-msmetafile
362. wml text/vnd.wap.wml
363. wmlc application/vnd.wap.wmlc
364. wmls text/vnd.wap.wmlscript
365. wmlsc application/vnd.wap.wmlscriptc
366. wmlscript text/vnd.wap.wmlscript
367. wmv audio/x-ms-wmv
368. wmx video/x-ms-wmx
369. wmz application/x-ms-wmz
370. wpng image/x-up-wpng
371. wpt x-lml/x-gps
372. wri application/x-mswrite
373. wrl x-world/x-vrml
374. wrz x-world/x-vrml
375. ws text/vnd.wap.wmlscript
376. wsc application/vnd.wap.wmlscriptc
377. wv video/wavelet
378. wvx video/x-ms-wvx
379. wxl application/x-wxl
380. x-gzip application/x-gzip
381. xar application/vnd.xara
382. xbm image/x-xbitmap
383. xdm application/x-xdma
384. xdma application/x-xdma
385. xdw application/vnd.fujixerox.docuworks
386. xht application/xhtml+xml
387. xhtm application/xhtml+xml
388. xhtml application/xhtml+xml
389. xla application/vnd.ms-excel
390. xlc application/vnd.ms-excel
391. xll application/x-excel
392. xlm application/vnd.ms-excel
393. xls application/vnd.ms-excel
394. xlt application/vnd.ms-excel
395. xlw application/vnd.ms-excel
396. xm audio/x-mod
397. xml text/xml
398. xmz audio/x-mod
399. xpi application/x-xpinstall
400. xpm image/x-xpixmap
401. xsit text/xml
402. xsl text/xml
403. xul text/xul
404. xwd image/x-xwindowdump
405. xyz chemical/x-pdb
406. yz1 application/x-yz1
407. z application/x-compress
408. zac application/x-zaurus-zac
409. zip application/zip