（转）File Header文件头，通过检查文件头来判断文件类型

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1. function?checkFileType($fileName){??
2. ????????$file?????=?fopen($fileName,?"rb");??
3. ????????$bin??????=?fread($file,?2);?//只读2字节??
4. ????????fclose($file);??
5. ????????$strInfo??=?@unpack("C2chars",?$bin);//?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??
6. ????????$typeCode?=?intval($strInfo['chars1'].$strInfo['chars2']);??
7. ????????$fileType?=?'';??
8. ????????if($typeCode?==?255216?/*jpg*/?||?$typeCode?==?7173?/*gif*/?||?$typeCode?==?13780?/*png*/)?{??
9. ????????????return?true;??
10. ????????}else{??
11. ????????????return?false;??
12. ????????}??
13. ????}??

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File Header文件头，通过检查文件头来判断文件类型

由这些文件头即使文件后缀被乱改也可以通过查看二进制文件查出文件的匹配格式,当然这就是一些播放器识别文件的方法
1、从Ultra－edit-32中提取出来的

JPEG (jpg)，文件头：FFD8FF?
PNG (png)，文件头：89504E47?
GIF (gif)，文件头：47494638?
TIFF (tif)，文件头：49492A00?
Windows Bitmap (bmp)，文件头：424D?
CAD (dwg)，文件头：41433130?
Adobe Photoshop (psd)，文件头：38425053?
Rich Text Format (rtf)，文件头：7B5C727466?
XML (xml)，文件头：3C3F786D6C?
HTML (html)，文件头：68746D6C3E?
Email [thorough only] (eml)，文件头：44656C69766572792D646174653A?
Outlook Express (dbx)，文件头：CFAD12FEC5FD746F?
Outlook (pst)，文件头：2142444E?
MS Word/Excel (xls.or.doc)，文件头：D0CF11E0?
MS Access (mdb)，文件头：5374616E64617264204A?
WordPerfect (wpd)，文件头：FF575043?
Postscript (eps.or.ps)，文件头：252150532D41646F6265?
Adobe Acrobat (pdf)，文件头：255044462D312E?
Quicken (qdf)，文件头：AC9EBD8F?
Windows Password (pwl)，文件头：E3828596?
ZIP Archive (zip)，文件头：504B0304?
RAR Archive (rar)，文件头：52617221?
Wave (wav)，文件头：57415645?
AVI (avi)，文件头：41564920?
Real Audio (ram)，文件头：2E7261FD?
Real Media (rm)，文件头：2E524D46?
MPEG (mpg)，文件头：000001BA?
MPEG (mpg)，文件头：000001B3?
Quicktime (mov)，文件头：6D6F6F76?
Windows Media (asf)，文件头：3026B2758E66CF11?
MIDI (mid)，文件头：4D546864?

二、从winhex中取出的文件头列表
File???????????????????????????? Type??????????????????????????ExtensionsHeader
JPEG???????????????????????????? jpg;jpeg??????????????????????0xFFD8FF
PNG??????????????????????????????png?????????????????????????? 0x89504E470D0A1A0A
GIF??????????????????????????????gif?????????????????????????? GIF8
TIFF???????????????????????????? tif;tiff??????????????????????0x49492A00
TIFF???????????????????????????? tif;tiff??????????????????????0x4D4D002A
Bit?? map???????????????????????? bmp?????????????????????????? BM
AOL ART??????????????????????????art?????????????????????????? 0x4A47040E000000
AOL ART??????????????????????????art?????????????????????????? 0x4A47030E000000
PC Paintbrush????????????????????pcx?????????????????????????? 0x0A050108
Graphics Metafile????????????????wmf?????????????????????????? 0xD7CDC69A
Graphics Metafile????????????????wmf?????????????????????????? 0x01000900
Graphics Metafile????????????????wmf?????????????????????????? 0x02000900
Enhanced Metafile????????????????emf?????????????????????????? 0x0100000058000000
Corel Draw?????????????????????? cdr?????????????????????????? CDR
CAD??????????????????????????????dwg?????????????????????????? 0x41433130
Adobe Photoshop??????????????????psd?????????????????????????? 8BPS
Rich Text Format???????????????? rtf?????????????????????????? rtf
XML??????????????????????????????xml??????????????????????????????
HTML???????????????? html;htm;php;php3;php4;phtml;shtml???????? type
Email????????????????????????????eml????????????????????????????Delivery-date:
Outlook Express??????????????????dbx????????????????????????????0xCFAD12FE
Outlookpst!BDN
MS Office/OLE2???? doc;xls;dot;ppt;xla;ppa;pps;pot;msi;sdw;db?? 0xD0CF11E0A1B11AE1
MS Access???????????????? mdb;mda;mde;mdt?????????????????????? Standard J
WordPerfect??????????????????????wpd?????????????????????????? 0xFF575043
OpenOffice Writer????????????????sxw?????????????????????????? writer
OpenOffice Calc??????????????????sxc?????????????????????????? calc
OpenOffice Math??????????????????sxm?????????????????????????? math
OpenOffice Impress?????????????? sxi?????????????????????????? impress
OpenOffice Draw??????????????????sxd?????????????????????????? draw
Adobe FrameMaker???????????????? fm????????????????????????????<MAKERFILE
PostScript?????????????????????? eps.or.ps;ps;eps??????????????%!PS-Adobe
Adobe Acrobat????????????????????pdf?????????????????????????? %PDF-1.
Quicken??????????????????????????qdf?????????????????????????? 0xAC9EBD8F
QuickBooks Backup????????????????qbb?????????????????????????? 0x458600000600
Sage???????????????????????????? sly.or.srt.or.slt;sly;srt;slt??????0x53520100
Sage Backup??????????????????????1??????????????????????????????????SAGEBACKUP
Lotus WordPro v9???????????????? lwp?????????????????????????? 0x576F726450726F
Lotus 123 v9???????????????????? 123?????????????????????????? 0x00001A00051004
Lotus 123 v5???????????????????? wk4?????????????????????????? 0x00001A0002100400
Lotus 123 v3???????????????????? wk3?????????????????????????? 0x00001A0000100400
Lotus 123 v1???????????????????? wk1????????????????????????????0x2000604060
Windows Password???????????????? pwl????????????????????????????0xE3828596
ZIP Archive??????????????????????zip;jar????????????????????????0x504B0304
ZIP Archive (outdated)?????????? zip????????????????????????????0x504B3030
RAR Archive??????????????????????rar????????????????????????????Rar!
GZ Archive?????????????????????? gz;tgz???????????????????????? 0x1F8B08
BZIP Archive???????????????????? bz2????????????????????????????BZh
ARJ Archive??????????????????????arj????????????????????????????0x60EA
7－ZIP Archive?????????????????? 7z???????????????????????????? 7z集'
Wave???????????????????????????? wav????????????????????????????WAVE
AVI??????????????????????????????avi????????????????????????????AVI?
Real Audio?????????????????????? ram;ra???????????????????????? .ra?0
Real Media?????????????????????? rm???????????????????????????? .RMF
MPEG???????????????????????????? mpg;mpeg?????????????????????? 0x000001BA
MPEG???????????????????????????? mpg;mpeg?????????????????????? 0x000001B3
Quicktime????????????????????????mov????????????????????????????moov
Windows Media????????????????????asf????????????????????????????0x3026B2758E66CF11
MIDI???????????????????????????? mid????????????????????????????MThd
Win32 Executable???????????????? exe;dll;drv;vxd;sys;ocx;vbx????MZ
Win16 Executable???????????????? exe;dll;drv;vxd;sys;ocx;vbx????MZ
ELF Executable?????????????????? elf;;??????????????????????????0x7F454C4601010100

以上两篇文章转自http://hi.csdn.net/huliang82