什么是 MIME TYPE？

一、首先，我们要了解浏览器是如何处理内容的。在浏览器中显示的内容有 HTML、有 XML、有 GIF、还有 Flash ……那么，浏览器是如何区分它们，决定什么内容用什么形式来显示呢？答案是 MIME Type，也就是该资源的媒体类型。

媒体类型通常是通过 HTTP 协议，由 Web 服务器告知浏览器的，更准确地说，是通过 Content-Type 来表示的，例如:

Content-Type: text/HTML

表示内容是 text/HTML 类型，也就是超文本文件。为什么是“text/HTML”而不是“HTML/text”或者别的什么？MIME Type 不是个人指定的，是经过 ietf 组织协商，以 RFC 的形式作为建议的标准发布在网上的，大多数的 Web 服务器和用户代理都会支持这个规范 (顺便说一句，Email 附件的类型也是通过 MIME Type 指定的)。

通常只有一些在互联网上获得广泛应用的格式才会获得一个 MIME Type，如果是某个客户端自己定义的格式，一般只能以 application/x- 开头。

XHTML 正是一个获得广泛应用的格式，因此，在 RFC 3236 中，说明了 XHTML 格式文件的 MIME Type 应该是 application/xHTML+XML。

当然，处理本地的文件，在没有人告诉浏览器某个文件的 MIME Type 的情况下，浏览器也会做一些默认的处理，这可能和你在操作系统中给文件配置的 MIME Type 有关。比如在 Windows 下，打开注册表的“HKEY_LOCAL_MACHINESOFTWAREClassesMIMEDatabaseContent Type”主键，你可以看到所有 MIME Type 的配置信息。

二、在把输出结果传送到浏览器上的时候，浏览器必须启动适当的应用程序来处理这个输出文档。这可以通过多种类型MIME（多功能网际邮件扩充协议）来完成。在HTTP中，MIME类型被定义在Content-Type header中。

例如，架设你要传送一个Microsoft Excel文件到客户端。那么这时的MIME类型就是“application/vnd.ms-excel”。在大多数实际情况中，这个文件然后将传送给Execl来处理（假设我们设定Execl为处理特殊MIME类型的应用程序）。在ASP中，设定MIME类型的方法是通过Response对象的ContentType属性。

多媒体文件格式MIME

最早的HTTP协议中，并没有附加的数据类型信息，所有传送的数据都被客户程序解释为超文本标记语言HTML 文档，而为了支持多媒体数据类型，HTTP协议中就使用了附加在文档之前的MIME数据类型信息来标识数据类型。

MIME意为多目Internet邮件扩展，它设计的最初目的是为了在发送电子邮件时附加多媒体数据，让邮件客户程序能根据其类型进行处理。然而当它被HTTP协议支持之后，它的意义就更为显著了。它使得HTTP传输的不仅是普通的文本，而变得丰富多彩。

每个MIME类型由两部分组成，前面是数据的大类别，例如声音audio、图象image等，后面定义具体的种类。

常见的MIME类型

超文本标记语言文本 .html,.html text/html

普通文本 .txt text/plain

RTF文本 .rtf application/rtf

GIF图形 .gif image/gif

JPEG图形 .ipeg,.jpg image/jpeg

au声音文件 .au audio/basic

MIDI音乐文件 mid,.midi audio/midi,audio/x-midi

RealAudio音乐文件 .ra, .ram audio/x-pn-realaudio

MPEG文件 .mpg,.mpeg video/mpeg

AVI文件 .avi video/x-msvideo

GZIP文件 .gz application/x-gzip

TAR文件 .tar application/x-tar

Internet中有一个专门组织IANA来确认标准的MIME类型，但Internet发展的太快，很多应用程序等不及IANA来确认他们使用的MIME类型为标准类型。因此他们使用在类别中以x-开头的方法标识这个类别还没有成为标准，例如：x-gzip，x-tar等。事实上这些类型运用的很广泛，已经成为了事实标准。只要客户机和服务器共同承认这个MIME类型，即使它是不标准的类型也没有关系，客户程序就能根据MIME类型，采用具体的处理手段来处理数据。而Web服务器和浏览器（包括操作系统）中，缺省都设置了标准的和常见的MIME类型，只有对于不常见的 MIME类型，才需要同时设置服务器和客户浏览器，以进行识别。

由于MIME类型与文档的后缀相关，因此服务器使用文档的后缀来区分不同文件的MIME类型，服务器中必须定义文档后缀和MIME类型之间的对应关系。而客户程序从服务器上接收数据的时候，它只是从服务器接受数据流，并不了解文档的名字，因此服务器必须使用附加信息来告诉客户程序数据的MIME类型。服务器在发送真正的数据之前，就要先发送标志数据的MIME类型的信息，这个信息使用Content-type关键字进行定义，例如对于HTML文档，服务器将首先发送以下两行MIME标识信息,这个标识并不是真正的数据文件的一部分。

Content-type: text/html

注意，第二行为一个空行，这是必须的，使用这个空行的目的是将MIME信息与真正的数据内容分隔开。

MIME (Multipurpose Internet Mail Extensions) 是描述消息内容类型的因特网标准。

MIME 消息能包含文本、图像、音频、视频以及其他应用程序专用的数据。

官方的 MIME 信息是由 Internet Engineering Task Force (IETF) 在下面的文档中提供的：

RFC-822 Standard for ARPA Internet text messages

RFC-2045 MIME Part 1: Format of Internet Message Bodies

RFC-2046 MIME Part 2: Media Types

RFC-2047 MIME Part 3: Header Extensions for Non-ASCII Text

RFC-2048 MIME Part 4: Registration Procedures

RFC-2049 MIME Part 5: Conformance Criteria and Examples

不同的应用程序支持不同的 MIME 类型。

Suffixes applicable Media type and subtype(s)

.3dm	x-world/x-3dmf
.3dmf	x-world/x-3dmf
.a	application/octet-stream
.aab	application/x-authorware-bin
.aam	application/x-authorware-map
.aas	application/x-authorware-seg
.abc	text/vnd.abc
.acgi	text/html
.afl	video/animaflex
.ai	application/postscript
.aif	audio/aiff
.aif	audio/x-aiff
.aifc	audio/aiff
.aifc	audio/x-aiff
.aiff	audio/aiff
.aiff	audio/x-aiff
.aim	application/x-aim
.aip	text/x-audiosoft-intra
.ani	application/x-navi-animation
.aos	application/x-nokia-9000-communicator-add-on-software
.aps	application/mime
.arc	application/octet-stream
.arj	application/arj
.arj	application/octet-stream
.art	image/x-jg
.asf	video/x-ms-asf
.asm	text/x-asm
.asp	text/asp
.asx	application/x-mplayer2
.asx	video/x-ms-asf
.asx	video/x-ms-asf-plugin
.au	audio/basic
.au	audio/x-au
.avi	application/x-troff-msvideo
.avi	video/avi
.avi	video/msvideo
.avi	video/x-msvideo
.avs	video/avs-video
.bcpio	application/x-bcpio
.bin	application/mac-binary
.bin	application/macbinary
.bin	application/octet-stream
.bin	application/x-binary
.bin	application/x-macbinary
.bm	image/bmp
.bmp	image/bmp
.bmp	image/x-windows-bmp
.boo	application/book
.book	application/book
.boz	application/x-bzip2
.bsh	application/x-bsh
.bz	application/x-bzip
.bz2	application/x-bzip2
.c	text/plain
.c	text/x-c
.c++	text/plain
.cat	application/vnd.ms-pki.seccat
.cc	text/plain
.cc	text/x-c
.ccad	application/clariscad
.cco	application/x-cocoa
.cdf	application/cdf
.cdf	application/x-cdf
.cdf	application/x-netcdf
.cer	application/pkix-cert
.cer	application/x-x509-ca-cert
.cha	application/x-chat
.chat	application/x-chat
.class	application/java
.class	application/java-byte-code
.class	application/x-java-class
.com	application/octet-stream
.com	text/plain
.conf	text/plain
.cpio	application/x-cpio
.cpp	text/x-c
.cpt	application/mac-compactpro
.cpt	application/x-compactpro
.cpt	application/x-cpt
.crl	application/pkcs-crl
.crl	application/pkix-crl
.crt	application/pkix-cert
.crt	application/x-x509-ca-cert
.crt	application/x-x509-user-cert
.csh	application/x-csh
.csh	text/x-script.csh
.css	application/x-pointplus
.css	text/css
.cxx	text/plain
.dcr	application/x-director
.deepv	application/x-deepv
.def	text/plain
.der	application/x-x509-ca-cert
.dif	video/x-dv
.dir	application/x-director
.dl	video/dl
.dl	video/x-dl
.doc	application/msword
.dot	application/msword
.dp	application/commonground
.drw	application/drafting
.dump	application/octet-stream
.dv	video/x-dv
.dvi	application/x-dvi
.dwf	drawing/x-dwf (old)
.dwf	model/vnd.dwf
.dwg	application/acad
.dwg	image/vnd.dwg
.dwg	image/x-dwg
.dxf	application/dxf
.dxf	image/vnd.dwg
.dxf	image/x-dwg
.dxr	application/x-director
.el	text/x-script.elisp
.elc	application/x-bytecode.elisp (compiled elisp)
.elc	application/x-elc
.env	application/x-envoy
.eps	application/postscript
.es	application/x-esrehber
.etx	text/x-setext
.evy	application/envoy
.evy	application/x-envoy
.exe	application/octet-stream
.f	text/plain
.f	text/x-fortran
.f77	text/x-fortran
.f90	text/plain
.f90	text/x-fortran
.fdf	application/vnd.fdf
.fif	application/fractals
.fif	image/fif
.fli	video/fli
.fli	video/x-fli
.flo	image/florian
.flx	text/vnd.fmi.flexstor
.fmf	video/x-atomic3d-feature
.for	text/plain
.for	text/x-fortran
.fpx	image/vnd.fpx
.fpx	image/vnd.net-fpx
.frl	application/freeloader
.funk	audio/make
.g	text/plain
.g3	image/g3fax
.gif	image/gif
.gl	video/gl
.gl	video/x-gl
.gsd	audio/x-gsm
.gsm	audio/x-gsm
.gsp	application/x-gsp
.gss	application/x-gss
.gtar	application/x-gtar
.gz	application/x-compressed
.gz	application/x-gzip
.gzip	application/x-gzip
.gzip	multipart/x-gzip
.h	text/plain
.h	text/x-h
.hdf	application/x-hdf
.help	application/x-helpfile
.hgl	application/vnd.hp-hpgl
.hh	text/plain
.hh	text/x-h
.hlb	text/x-script
.hlp	application/hlp
.hlp	application/x-helpfile
.hlp	application/x-winhelp
.hpg	application/vnd.hp-hpgl
.hpgl	application/vnd.hp-hpgl
.hqx	application/binhex
.hqx	application/binhex4
.hqx	application/mac-binhex
.hqx	application/mac-binhex40
.hqx	application/x-binhex40
.hqx	application/x-mac-binhex40
.hta	application/hta
.htc	text/x-component
.htm	text/html
.html	text/html
.htmls	text/html
.htt	text/webviewhtml
.htx	text/html
.ice	x-conference/x-cooltalk
.ico	image/x-icon
.idc	text/plain
.ief	image/ief
.iefs	image/ief
.iges	application/iges
.iges	model/iges
.igs	application/iges
.igs	model/iges
.ima	application/x-ima
.imap	application/x-httpd-imap
.inf	application/inf
.ins	application/x-internett-signup
.ip	application/x-ip2
.isu	video/x-isvideo
.it	audio/it
.iv	application/x-inventor
.ivr	i-world/i-vrml
.ivy	application/x-livescreen
.jam	audio/x-jam
.jav	text/plain
.jav	text/x-java-source
.java	text/plain
.java	text/x-java-source
.jcm	application/x-java-commerce
.jfif	image/jpeg
.jfif	image/pjpeg
.jfif-tbnl	image/jpeg
.jpe	image/jpeg
.jpe	image/pjpeg
.jpeg	image/jpeg
.jpeg	image/pjpeg
.jpg	image/jpeg
.jpg	image/pjpeg
.jps	image/x-jps
.js	application/x-javascript
.js	application/javascript
.js	application/ecmascript
.js	text/javascript
.js	text/ecmascript
.jut	image/jutvision
.kar	audio/midi
.kar	music/x-karaoke
.ksh	application/x-ksh
.ksh	text/x-script.ksh
.la	audio/nspaudio
.la	audio/x-nspaudio
.lam	audio/x-liveaudio
.latex	application/x-latex
.lha	application/lha
.lha	application/octet-stream
.lha	application/x-lha
.lhx	application/octet-stream
.list	text/plain
.lma	audio/nspaudio
.lma	audio/x-nspaudio
.log	text/plain
.lsp	application/x-lisp
.lsp	text/x-script.lisp
.lst	text/plain
.lsx	text/x-la-asf
.ltx	application/x-latex
.lzh	application/octet-stream
.lzh	application/x-lzh
.lzx	application/lzx
.lzx	application/octet-stream
.lzx	application/x-lzx
.m	text/plain
.m	text/x-m
.m1v	video/mpeg
.m2a	audio/mpeg
.m2v	video/mpeg
.m3u	audio/x-mpequrl
.man	application/x-troff-man
.map	application/x-navimap
.mar	text/plain
.mbd	application/mbedlet
.mc$	application/x-magic-cap-package-1.0
.mcd	application/mcad
.mcd	application/x-mathcad
.mcf	image/vasa
.mcf	text/mcf
.mcp	application/netmc
.me	application/x-troff-me
.mht	message/rfc822
.mhtml	message/rfc822
.mid	application/x-midi
.mid	audio/midi
.mid	audio/x-mid
.mid	audio/x-midi
.mid	music/crescendo
.mid	x-music/x-midi
.midi	application/x-midi
.midi	audio/midi
.midi	audio/x-mid
.midi	audio/x-midi
.midi	music/crescendo
.midi	x-music/x-midi
.mif	application/x-frame
.mif	application/x-mif
.mime	message/rfc822
.mime	www/mime
.mjf	audio/x-vnd.audioexplosion.mjuicemediafile
.mjpg	video/x-motion-jpeg
.mm	application/base64
.mm	application/x-meme
.mme	application/base64
.mod	audio/mod
.mod	audio/x-mod
.moov	video/quicktime
.mov	video/quicktime
.movie	video/x-sgi-movie
.mp2	audio/mpeg
.mp2	audio/x-mpeg
.mp2	video/mpeg
.mp2	video/x-mpeg
.mp2	video/x-mpeq2a
.mp3	audio/mpeg3
.mp3	audio/x-mpeg-3
.mp3	video/mpeg
.mp3	video/x-mpeg
.mpa	audio/mpeg
.mpa	video/mpeg
.mpc	application/x-project
.mpe	video/mpeg
.mpeg	video/mpeg
.mpg	audio/mpeg
.mpg	video/mpeg
.mpga	audio/mpeg
.mpp	application/vnd.ms-project
.mpt	application/x-project
.mpv	application/x-project
.mpx	application/x-project
.mrc	application/marc
.ms	application/x-troff-ms
.mv	video/x-sgi-movie
.my	audio/make
.mzz	application/x-vnd.audioexplosion.mzz
.nap	image/naplps
.naplps	image/naplps
.nc	application/x-netcdf
.ncm	application/vnd.nokia.configuration-message
.nif	image/x-niff
.niff	image/x-niff
.nix	application/x-mix-transfer
.nsc	application/x-conference
.nvd	application/x-navidoc
.o	application/octet-stream
.oda	application/oda
.omc	application/x-omc
.omcd	application/x-omcdatamaker
.omcr	application/x-omcregerator
.p	text/x-pascal
.p10	application/pkcs10
.p10	application/x-pkcs10
.p12	application/pkcs-12
.p12	application/x-pkcs12
.p7a	application/x-pkcs7-signature
.p7c	application/pkcs7-mime
.p7c	application/x-pkcs7-mime
.p7m	application/pkcs7-mime
.p7m	application/x-pkcs7-mime
.p7r	application/x-pkcs7-certreqresp
.p7s	application/pkcs7-signature
.part	application/pro_eng
.pas	text/pascal
.pbm	image/x-portable-bitmap
.pcl	application/vnd.hp-pcl
.pcl	application/x-pcl
.pct	image/x-pict
.pcx	image/x-pcx
.pdb	chemical/x-pdb
.pdf	application/pdf
.pfunk	audio/make
.pfunk	audio/make.my.funk
.pgm	image/x-portable-graymap
.pgm	image/x-portable-greymap
.pic	image/pict
.pict	image/pict
.pkg	application/x-newton-compatible-pkg
.pko	application/vnd.ms-pki.pko
.pl	text/plain
.pl	text/x-script.perl
.plx	application/x-pixclscript
.pm	image/x-xpixmap
.pm	text/x-script.perl-module
.pm4	application/x-pagemaker
.pm5	application/x-pagemaker
.png	image/png
.pnm	application/x-portable-anymap
.pnm	image/x-portable-anymap
.pot	application/mspowerpoint
.pot	application/vnd.ms-powerpoint
.pov	model/x-pov
.ppa	application/vnd.ms-powerpoint
.ppm	image/x-portable-pixmap
.pps	application/mspowerpoint
.pps	application/vnd.ms-powerpoint
.ppt	application/mspowerpoint
.ppt	application/powerpoint
.ppt	application/vnd.ms-powerpoint
.ppt	application/x-mspowerpoint
.ppz	application/mspowerpoint
.pre	application/x-freelance
.prt	application/pro_eng
.ps	application/postscript
.psd	application/octet-stream
.pvu	paleovu/x-pv
.pwz	application/vnd.ms-powerpoint
.py	text/x-script.phyton
.pyc	application/x-bytecode.python
.qcp	audio/vnd.qcelp
.qd3	x-world/x-3dmf
.qd3d	x-world/x-3dmf
.qif	image/x-quicktime
.qt	video/quicktime
.qtc	video/x-qtc
.qti	image/x-quicktime
.qtif	image/x-quicktime
.ra	audio/x-pn-realaudio
.ra	audio/x-pn-realaudio-plugin
.ra	audio/x-realaudio
.ram	audio/x-pn-realaudio
.ras	application/x-cmu-raster
.ras	image/cmu-raster
.ras	image/x-cmu-raster
.rast	image/cmu-raster
.rexx	text/x-script.rexx
.rf	image/vnd.rn-realflash
.rgb	image/x-rgb
.rm	application/vnd.rn-realmedia
.rm	audio/x-pn-realaudio
.rmi	audio/mid
.rmm	audio/x-pn-realaudio
.rmp	audio/x-pn-realaudio
.rmp	audio/x-pn-realaudio-plugin
.rng	application/ringing-tones
.rng	application/vnd.nokia.ringing-tone
.rnx	application/vnd.rn-realplayer
.roff	application/x-troff
.rp	image/vnd.rn-realpix
.rpm	audio/x-pn-realaudio-plugin
.rt	text/richtext
.rt	text/vnd.rn-realtext
.rtf	application/rtf
.rtf	application/x-rtf
.rtf	text/richtext
.rtx	application/rtf
.rtx	text/richtext
.rv	video/vnd.rn-realvideo
.s	text/x-asm
.s3m	audio/s3m
.saveme	application/octet-stream
.sbk	application/x-tbook
.scm	application/x-lotusscreencam
.scm	text/x-script.guile
.scm	text/x-script.scheme
.scm	video/x-scm
.sdml	text/plain
.sdp	application/sdp
.sdp	application/x-sdp
.sdr	application/sounder
.sea	application/sea
.sea	application/x-sea
.set	application/set
.sgm	text/sgml
.sgm	text/x-sgml
.sgml	text/sgml
.sgml	text/x-sgml
.sh	application/x-bsh
.sh	application/x-sh
.sh	application/x-shar
.sh	text/x-script.sh
.shar	application/x-bsh
.shar	application/x-shar
.shtml	text/html
.shtml	text/x-server-parsed-html
.sid	audio/x-psid
.sit	application/x-sit
.sit	application/x-stuffit
.skd	application/x-koan
.skm	application/x-koan
.skp	application/x-koan
.skt	application/x-koan
.sl	application/x-seelogo
.smi	application/smil
.smil	application/smil
.snd	audio/basic
.snd	audio/x-adpcm
.sol	application/solids
.spc	application/x-pkcs7-certificates
.spc	text/x-speech
.spl	application/futuresplash
.spr	application/x-sprite
.sprite	application/x-sprite
.src	application/x-wais-source
.ssi	text/x-server-parsed-html
.ssm	application/streamingmedia
.sst	application/vnd.ms-pki.certstore
.step	application/step
.stl	application/sla
.stl	application/vnd.ms-pki.stl
.stl	application/x-navistyle
.stp	application/step
.sv4cpio	application/x-sv4cpio
.sv4crc	application/x-sv4crc
.svf	image/vnd.dwg
.svf	image/x-dwg
.svr	application/x-world
.svr	x-world/x-svr
.swf	application/x-shockwave-flash
.t	application/x-troff
.talk	text/x-speech
.tar	application/x-tar
.tbk	application/toolbook
.tbk	application/x-tbook
.tcl	application/x-tcl
.tcl	text/x-script.tcl
.tcsh	text/x-script.tcsh
.tex	application/x-tex
.texi	application/x-texinfo
.texinfo	application/x-texinfo
.text	application/plain
.text	text/plain
.tgz	application/gnutar
.tgz	application/x-compressed
.tif	image/tiff
.tif	image/x-tiff
.tiff	image/tiff
.tiff	image/x-tiff
.tr	application/x-troff
.tsi	audio/tsp-audio
.tsp	application/dsptype
.tsp	audio/tsplayer
.tsv	text/tab-separated-values
.turbot	image/florian
.txt	text/plain
.uil	text/x-uil
.uni	text/uri-list
.unis	text/uri-list
.unv	application/i-deas
.uri	text/uri-list
.uris	text/uri-list
.ustar	application/x-ustar
.ustar	multipart/x-ustar
.uu	application/octet-stream
.uu	text/x-uuencode
.uue	text/x-uuencode
.vcd	application/x-cdlink
.vcs	text/x-vcalendar
.vda	application/vda
.vdo	video/vdo
.vew	application/groupwise
.viv	video/vivo
.viv	video/vnd.vivo
.vivo	video/vivo
.vivo	video/vnd.vivo
.vmd	application/vocaltec-media-desc
.vmf	application/vocaltec-media-file
.voc	audio/voc
.voc	audio/x-voc
.vos	video/vosaic
.vox	audio/voxware
.vqe	audio/x-twinvq-plugin
.vqf	audio/x-twinvq
.vql	audio/x-twinvq-plugin
.vrml	application/x-vrml
.vrml	model/vrml
.vrml	x-world/x-vrml
.vrt	x-world/x-vrt
.vsd	application/x-visio
.vst	application/x-visio
.vsw	application/x-visio
.w60	application/wordperfect6.0
.w61	application/wordperfect6.1
.w6w	application/msword
.wav	audio/wav
.wav	audio/x-wav
.wb1	application/x-qpro
.wbmp	image/vnd.wap.wbmp
.web	application/vnd.xara
.wiz	application/msword
.wk1	application/x-123
.wmf	windows/metafile
.wml	text/vnd.wap.wml
.wmlc	application/vnd.wap.wmlc
.wmls	text/vnd.wap.wmlscript
.wmlsc	application/vnd.wap.wmlscriptc
.word	application/msword
.wp	application/wordperfect
.wp5	application/wordperfect
.wp5	application/wordperfect6.0
.wp6	application/wordperfect
.wpd	application/wordperfect
.wpd	application/x-wpwin
.wq1	application/x-lotus
.wri	application/mswrite
.wri	application/x-wri
.wrl	application/x-world
.wrl	model/vrml
.wrl	x-world/x-vrml
.wrz	model/vrml
.wrz	x-world/x-vrml
.wsc	text/scriplet
.wsrc	application/x-wais-source
.wtk	application/x-wintalk
.xbm	image/x-xbitmap
.xbm	image/x-xbm
.xbm	image/xbm
.xdr	video/x-amt-demorun
.xgz	xgl/drawing
.xif	image/vnd.xiff
.xl	application/excel
.xla	application/excel
.xla	application/x-excel
.xla	application/x-msexcel
.xlb	application/excel
.xlb	application/vnd.ms-excel
.xlb	application/x-excel
.xlc	application/excel
.xlc	application/vnd.ms-excel
.xlc	application/x-excel
.xld	application/excel
.xld	application/x-excel
.xlk	application/excel
.xlk	application/x-excel
.xll	application/excel
.xll	application/vnd.ms-excel
.xll	application/x-excel
.xlm	application/excel
.xlm	application/vnd.ms-excel
.xlm	application/x-excel
.xls	application/excel
.xls	application/vnd.ms-excel
.xls	application/x-excel
.xls	application/x-msexcel
.xlt	application/excel
.xlt	application/x-excel
.xlv	application/excel
.xlv	application/x-excel
.xlw	application/excel
.xlw	application/vnd.ms-excel
.xlw	application/x-excel
.xlw	application/x-msexcel
.xm	audio/xm
.xml	application/xml
.xml	text/xml
.xmz	xgl/movie
.xpix	application/x-vnd.ls-xpix
.xpm	image/x-xpixmap
.xpm	image/xpm
.x-png	image/png
.xsr	video/x-amt-showrun
.xwd	image/x-xwd
.xwd	image/x-xwindowdump
.xyz	chemical/x-pdb
.z	application/x-compress
.z	application/x-compressed
.zip	application/x-compressed
.zip	application/x-zip-compressed
.zip	application/zip
.zip	multipart/x-zip
.zoo	application/octet-stream
.zsh	text/x-script.zsh