Erlang mime type

Question

How can i know mime type of file with Erlang?

Thank you.

Answer 1

Maybe you can use this: mochiweb_mime:from_extension(filename:extension(File))

%% @author Bob Ippolito %% @copyright 2007 Mochi Media, Inc.

%% @doc Gives a good MIME type guess based on file extension.

-module(mochiweb_mime). -author('bob@mochimedia.com'). -export([from_extension/1]).

%% @spec from_extension(S::string()) -> string() | undefined %% @doc Given a filename extension (e.g. ".html") return a guess for the MIME %% type such as "text/html". Will return the atom undefined if no good %% guess is available.

from_extension(".stl") -> "application/SLA"; from_extension(".stp") -> "application/STEP"; from_extension(".step") -> "application/STEP"; from_extension(".dwg") -> "application/acad"; from_extension(".ez") -> "application/andrew-inset"; from_extension(".ccad") -> "application/clariscad"; from_extension(".drw") -> "application/drafting"; from_extension(".tsp") -> "application/dsptype"; from_extension(".dxf") -> "application/dxf"; from_extension(".xls") -> "application/excel"; from_extension(".unv") -> "application/i-deas"; from_extension(".jar") -> "application/java-archive"; from_extension(".hqx") -> "application/mac-binhex40"; from_extension(".cpt") -> "application/mac-compactpro"; from_extension(".pot") -> "application/vnd.ms-powerpoint"; from_extension(".ppt") -> "application/vnd.ms-powerpoint"; from_extension(".dms") -> "application/octet-stream"; from_extension(".lha") -> "application/octet-stream"; from_extension(".lzh") -> "application/octet-stream"; from_extension(".oda") -> "application/oda"; from_extension(".ogg") -> "application/ogg"; from_extension(".ogm") -> "application/ogg"; from_extension(".pdf") -> "application/pdf"; from_extension(".pgp") -> "application/pgp"; from_extension(".ai") -> "application/postscript"; from_extension(".eps") -> "application/postscript"; from_extension(".ps") -> "application/postscript"; from_extension(".prt") -> "application/pro_eng"; from_extension(".rtf") -> "application/rtf"; from_extension(".smi") -> "application/smil"; from_extension(".smil") -> "application/smil"; from_extension(".sol") -> "application/solids"; from_extension(".vda") -> "application/vda"; from_extension(".xlm") -> "application/vnd.ms-excel"; from_extension(".cod") -> "application/vnd.rim.cod"; from_extension(".pgn") -> "application/x-chess-pgn"; from_extension(".cpio") -> "application/x-cpio"; from_extension(".csh") -> "application/x-csh"; from_extension(".deb") -> "application/x-debian-package"; from_extension(".dcr") -> "application/x-director"; from_extension(".dir") -> "application/x-director"; from_extension(".dxr") -> "application/x-director"; from_extension(".gz") -> "application/x-gzip"; from_extension(".hdf") -> "application/x-hdf"; from_extension(".ipx") -> "application/x-ipix"; from_extension(".ips") -> "application/x-ipscript"; from_extension(".js") -> "application/x-javascript"; from_extension(".skd") -> "application/x-koan"; from_extension(".skm") -> "application/x-koan"; from_extension(".skp") -> "application/x-koan"; from_extension(".skt") -> "application/x-koan"; from_extension(".latex") -> "application/x-latex"; from_extension(".lsp") -> "application/x-lisp"; from_extension(".scm") -> "application/x-lotusscreencam"; from_extension(".mif") -> "application/x-mif"; from_extension(".com") -> "application/x-msdos-program"; from_extension(".exe") -> "application/octet-stream"; from_extension(".cdf") -> "application/x-netcdf"; from_extension(".nc") -> "application/x-netcdf"; from_extension(".pl") -> "application/x-perl"; from_extension(".pm") -> "application/x-perl"; from_extension(".rar") -> "application/x-rar-compressed"; from_extension(".sh") -> "application/x-sh"; from_extension(".shar") -> "application/x-shar"; from_extension(".swf") -> "application/x-shockwave-flash"; from_extension(".sit") -> "application/x-stuffit"; from_extension(".sv4cpio") -> "application/x-sv4cpio"; from_extension(".sv4crc") -> "application/x-sv4crc"; from_extension(".tar.gz") -> "application/x-tar-gz"; from_extension(".tgz") -> "application/x-tar-gz"; from_extension(".tar") -> "application/x-tar"; from_extension(".tcl") -> "application/x-tcl"; from_extension(".texi") -> "application/x-texinfo"; from_extension(".texinfo") -> "application/x-texinfo"; from_extension(".man") -> "application/x-troff-man"; from_extension(".me") -> "application/x-troff-me"; from_extension(".ms") -> "application/x-troff-ms"; from_extension(".roff") -> "application/x-troff"; from_extension(".t") -> "application/x-troff"; from_extension(".tr") -> "application/x-troff"; from_extension(".ustar") -> "application/x-ustar"; from_extension(".src") -> "application/x-wais-source"; from_extension(".zip") -> "application/zip"; from_extension(".tsi") -> "audio/TSP-audio"; from_extension(".au") -> "audio/basic"; from_extension(".snd") -> "audio/basic"; from_extension(".kar") -> "audio/midi"; from_extension(".mid") -> "audio/midi"; from_extension(".midi") -> "audio/midi"; from_extension(".mp2") -> "audio/mpeg"; from_extension(".mp3") -> "audio/mpeg"; from_extension(".mpga") -> "audio/mpeg"; from_extension(".aif") -> "audio/x-aiff"; from_extension(".aifc") -> "audio/x-aiff"; from_extension(".aiff") -> "audio/x-aiff"; from_extension(".m3u") -> "audio/x-mpegurl"; from_extension(".wax") -> "audio/x-ms-wax"; from_extension(".wma") -> "audio/x-ms-wma"; from_extension(".rpm") -> "audio/x-pn-realaudio-plugin"; from_extension(".ram") -> "audio/x-pn-realaudio"; from_extension(".rm") -> "audio/x-pn-realaudio"; from_extension(".ra") -> "audio/x-realaudio"; from_extension(".wav") -> "audio/x-wav"; from_extension(".pdb") -> "chemical/x-pdb"; from_extension(".ras") -> "image/cmu-raster"; from_extension(".gif") -> "image/gif"; from_extension(".ief") -> "image/ief"; from_extension(".jpe") -> "image/jpeg"; from_extension(".jpeg") -> "image/jpeg"; from_extension(".jpg") -> "image/jpeg"; from_extension(".jp2") -> "image/jp2"; from_extension(".png") -> "image/png"; from_extension(".tif") -> "image/tiff"; from_extension(".tiff") -> "image/tiff"; from_extension(".pnm") -> "image/x-portable-anymap"; from_extension(".pbm") -> "image/x-portable-bitmap"; from_extension(".pgm") -> "image/x-portable-graymap"; from_extension(".ppm") -> "image/x-portable-pixmap"; from_extension(".rgb") -> "image/x-rgb"; from_extension(".xbm") -> "image/x-xbitmap"; from_extension(".xwd") -> "image/x-xwindowdump"; from_extension(".iges") -> "model/iges"; from_extension(".igs") -> "model/iges"; from_extension(".mesh") -> "model/mesh"; from_extension(".") -> ""; from_extension(".msh") -> "model/mesh"; from_extension(".silo") -> "model/mesh"; from_extension(".vrml") -> "model/vrml"; from_extension(".wrl") -> "model/vrml"; from_extension(".css") -> "text/css"; from_extension(".htm") -> "text/html"; from_extension(".html") -> "text/html"; from_extension(".asc") -> "text/plain"; from_extension(".c") -> "text/plain"; from_extension(".cc") -> "text/plain"; from_extension(".f90") -> "text/plain"; from_extension(".f") -> "text/plain"; from_extension(".hh") -> "text/plain"; from_extension(".m") -> "text/plain"; from_extension(".txt") -> "text/plain"; from_extension(".rtx") -> "text/richtext"; from_extension(".sgm") -> "text/sgml"; from_extension(".sgml") -> "text/sgml"; from_extension(".tsv") -> "text/tab-separated-values"; from_extension(".jad") -> "text/vnd.sun.j2me.app-descriptor"; from_extension(".etx") -> "text/x-setext"; from_extension(".xml") -> "application/xml"; from_extension(".dl") -> "video/dl"; from_extension(".fli") -> "video/fli"; from_extension(".flv") -> "video/flv"; from_extension(".gl") -> "video/gl"; from_extension(".mp4") -> "video/mp4"; from_extension(".mpe") -> "video/mpeg"; from_extension(".mpeg") -> "video/mpeg"; from_extension(".mpg") -> "video/mpeg"; from_extension(".mov") -> "video/quicktime"; from_extension(".qt") -> "video/quicktime"; from_extension(".viv") -> "video/vnd.vivo"; from_extension(".vivo") -> "video/vnd.vivo"; from_extension(".asf") -> "video/x-ms-asf"; from_extension(".asx") -> "video/x-ms-asx"; from_extension(".wmv") -> "video/x-ms-wmv"; from_extension(".wmx") -> "video/x-ms-wmx"; from_extension(".wvx") -> "video/x-ms-wvx"; from_extension(".avi") -> "video/x-msvideo"; from_extension(".movie") -> "video/x-sgi-movie"; from_extension(".mime") -> "www/mime"; from_extension(".ice") -> "x-conference/x-cooltalk"; from_extension(".vrm") -> "x-world/x-vrml"; from_extension(".spx") -> "audio/ogg"; from_extension(".xhtml") -> "application/xhtml+xml"; from_extension(".bz2") -> "application/x-bzip2"; from_extension(".doc") -> "application/msword"; from_extension(".z") -> "application/x-compress"; from_extension(".ico") -> "image/x-icon"; from_extension(".bmp") -> "image/bmp"; from_extension(".m4a") -> "audio/mpeg"; from_extension(".csv") -> "text/csv"; from_extension(_) -> undefined.

%% %% Tests %% -ifdef(TEST). -include_lib("eunit/include/eunit.hrl").

exhaustive_from_extension_test() -> T = mochiweb_cover:clause_lookup_table(?MODULE, from_extension), [?assertEqual(V, from_extension(K)) || {K, V} <- T].

from_extension_test() -> ?assertEqual("text/html", from_extension(".html")), ?assertEqual(undefined, from_extension("")), ?assertEqual(undefined, from_extension(".wtf")), ok.

-endif.

Answer 2

Depends on what you want. If it's not something critical you can be very unsophisticated and simply use the file command usually available in *NIX environments. It goes beyond guessing by file extension using several tests (file system, magic numbers, and text inspection).

1> os:cmd("file -i erl_crash.dump").
"erl_crash.dump: text/plain; charset=us-ascii\n"

You can get the bits you want parsing that output. It's pretty inefficient, since you spawn an OS process per call, but's dead simple.

If you need something efficient, you may want to write C driver (e.g. using libmagic) or a native implementation in erlang, but I'm not aware of any existing one.

Answer 3

If you want to know the mime type of a file based on its extension you can use the undocumented inets function httpd_conf:load_mime_types/1. This together with a mime.types file (there's one in one of the inets httpd examples in OTP) will give you a list of file extensions and their default associated mime types. The following code will give you the standard mime type for a given filename based on its extension:

mime_type(FileName) ->
    "." ++ Extension = filename:extension(FileName),
    MimeTypes = mime_types(),
    proplists:get_value(Extension, MimeTypes).

mime_types() ->
    MimeTypesFile = filename:join(code:lib_dir(inets), 
                                  "examples/server_root/conf/mime.types"),
    {ok, MimeTypes} = httpd_conf:load_mime_types(MimeTypesFile),
    MimeTypes.

You can now use mime_type/1 on a filename (e.g. example.pdf) and it will return you the default mime type if known (in this case "application/pdf") or undefined otherwise.

If you're going to do this operation repeatedly, it would be a good idea to cache the result of httpd_conf:load_mime_types/1 as the inets httpd server does, so that you avoid reading and parsing the mime types file all the time.