extension_to_filetype_map.rb

  EXTENSION_TO_MIMETYPE_MAP = {
    "3fr" => "image/x-hasselblad-3fr",
    "aa" => "audio/audible",
    "aae" => "application/vnd.apple.photos",
    "ai" => "application/vnd.adobe.illustrator",
    "aiff" => "audio/x-aiff",
    "alias" => "application/x-macos",
    "ape" => "audio/x-monkeys-audio",
    "apng" => "image/apng",
    "asf" => "video/x-ms-asf",
    "arw" => "image/x-sony-arw",
    "avi" => "video/x-msvideo",
    "bmp" => "image/bmp",
    "bpg" => "image/bpg",
    "btf" => "image/x-tiff-big",
    "bz2" => "application/bzip2",
    "canon 1d raw" => "image/x-raw",
    "chm" => "application/x-chm",
    "cos" => "application/octet-stream",
    "cr2" => "image/x-canon-cr2",
    "cr3" => "image/x-canon-cr3",
    "crm" => "video/x-canon-crm",
    "crw" => "image/x-canon-crw",
    "csv" => "text/csv",
    "czi" => "image/x-zeiss-czi",
    "dcm" => "application/dicom",
    "dcp" => "application/octet-stream",
    "dcr" => "image/x-kodak-dcr",
    "dcx" => "image/dcx",
    "dex" => "application/octet-stream",
    "dfont" => "application/x-dfont",
    "dicom" => "application/dicom",
    "divx" => "video/divx",
    "djvu" => "image/vnd.djvu",
    "dng" => "image/x-adobe-dng",
    "doc" => "application/msword",
    "docm" => "application/vnd.ms-word.document.macroEnabled",
    "docx" => "application/vnd.openxmlformats-officedocument.wordprocessingml.document",
    "dot" => "application/msword",
    "dotm" => "application/vnd.ms-word.template.macroEnabledTemplate",
    "dotx" => "application/vnd.openxmlformats-officedocument.wordprocessingml.template",
    "dpx" => "image/x-dpx",
    "dr4" => "application/octet-stream",
    "ds2" => "audio/x-ds2",
    "dss" => "audio/x-dss",
    "dv" => "video/x-dv",
    "dvr-ms" => "video/x-ms-dvr",
    "dwf" => "model/vnd.dwf",
    "dwg" => "image/vnd.dwg",
    "eip" => "application/x-captureone",
    "eps" => "application/postscript",
    "erf" => "image/x-epson-erf",
    "exe" => "application/octet-stream",
    "exr" => "image/x-exr",
    "exv" => "image/x-exv",
    "fff" => "image/x-hasselblad-fff",
    "fits" => "image/fits",
    "fla" => "application/vnd.adobe.fla",
    "flac" => "audio/flac",
    "flif" => "image/flif",
    "flir" => "image/x-flir-fff",
    "flv" => "video/x-flv",
    "font" => "application/x-font-type1",
    "fpf" => "image/x-flir-fpf",
    "fpx" => "image/vnd.fpx",
    "gif" => "image/gif",
    "gpr" => "image/x-gopro-gpr",
    "gzip" => "application/x-gzip",
    "hdp" => "image/vnd.ms-photo",
    "hdr" => "image/vnd.radiance",
    "heic" => "image/heic",
    "heif" => "image/heif",
    "htm" => "text/html",
    "html" => "text/html",
    "icc" => "application/vnd.iccprofile",
    "ico" => "image/x-icon",
    "ics" => "text/calendar",
    "idml" => "application/vnd.adobe.indesign-idml-package",
    "iiq" => "image/x-raw",
    "ind" => "application/x-indesign",
    "inx" => "application/x-indesign-interchange",
    "iso" => "application/x-iso9660-image",
    "itc" => "application/itunes",
    "j2c" => "image/x-j2c",
    "jng" => "image/jng",
    "jp2" => "image/jp2",
    "jpg" => "image/jpeg",
    "jpeg" => "image/jpeg",
    "jpm" => "image/jpm",
    "jpx" => "image/jpx",
    "json" => "application/json",
    "jxr" => "image/jxr",
    "k25" => "image/x-kodak-k25",
    "kdc" => "image/x-kodak-kdc",
    "key" => "application/x-iwork-keynote-sffkey",
    "lfp" => "image/x-lytro-lfp",
    "lnk" => "application/octet-stream",
    "lri" => "image/x-light-lri",
    "m2t" => "video/mpeg",
    "m2ts" => "video/m2ts",
    "max" => "application/x-3ds",
    "mef" => "image/x-mamiya-mef",
    "mie" => "application/x-mie",
    "miff" => "application/x-magick-image",
    "mka" => "audio/x-matroska",
    "mks" => "application/x-matroska",
    "mkv" => "video/x-matroska",
    "mng" => "video/mng",
    "mobi" => "application/x-mobipocket-ebook",
    "moi" => "application/octet-stream",
    "mos" => "image/x-raw",
    "mov" => "video/quicktime",
    "mp3" => "audio/mpeg",
    "mp4" => "video/mp4",
    "mpc" => "audio/x-musepack",
    "mpeg" => "video/mpeg",
    "mrw" => "image/x-minolta-mrw",
    "mxf" => "application/mxf",
    "nef" => "image/x-nikon-nef",
    "nrw" => "image/x-nikon-nrw",
    "numbers" => "application/x-iwork-numbers-sffnumbers",
    "odb" => "application/vnd.oasis.opendocument.database",
    "odc" => "application/vnd.oasis.opendocument.chart",
    "odf" => "application/vnd.oasis.opendocument.formula",
    "odg" => "application/vnd.oasis.opendocument.graphics",
    "odi" => "application/vnd.oasis.opendocument.image",
    "odp" => "application/vnd.oasis.opendocument.presentation",
    "ods" => "application/vnd.oasis.opendocument.spreadsheet",
    "odt" => "application/vnd.oasis.opendocument.text",
    "ogg" => "audio/ogg",
    "ogv" => "video/ogg",
    "onp" => "application/on1",
    "orf" => "image/x-olympus-orf",
    "otf" => "application/x-font-otf",
    "pages" => "application/x-iwork-pages-sffpages",
    "pbm" => "image/x-portable-bitmap",
    "pcd" => "image/x-photo-cd",
    "pcx" => "image/pcx",
    "pdb" => "application/vnd.palm",
    "pdf" => "application/pdf",
    "pef" => "image/x-pentax-pef",
    "pfa" => "application/x-font-type1",
    "pgf" => "image/pgf",
    "pgm" => "image/x-portable-graymap",
    "php" => "application/x-httpd-php",
    "pict" => "image/pict",
    "plist" => "application/xml",
    "pmp" => "image/x-sony-pmp",
    "png" => "image/png",
    "pot" => "application/vnd.ms-powerpoint",
    "potm" => "application/vnd.ms-powerpoint.template.macroEnabled",
    "potx" => "application/vnd.openxmlformats-officedocument.presentationml.template",
    "ppam" => "application/vnd.ms-powerpoint.addin.macroEnabled",
    "ppax" => "application/vnd.openxmlformats-officedocument.presentationml.addin",
    "ppm" => "image/x-portable-pixmap",
    "pps" => "application/vnd.ms-powerpoint",
    "ppsm" => "application/vnd.ms-powerpoint.slideshow.macroEnabled",
    "ppsx" => "application/vnd.openxmlformats-officedocument.presentationml.slideshow",
    "ppt" => "application/vnd.ms-powerpoint",
    "pptm" => "application/vnd.ms-powerpoint.presentation.macroEnabled",
    "pptx" => "application/vnd.openxmlformats-officedocument.presentationml.presentation",
    "ps" => "application/postscript",
    "psd" => "application/vnd.adobe.photoshop",
    "psp" => "image/x-paintshoppro",
    "qtif" => "image/x-quicktime",
    "r3d" => "video/x-red-r3d",
    "ra" => "audio/x-pn-realaudio",
    "raf" => "image/x-fujifilm-raf",
    "ram" => "audio/x-pn-realaudio",
    "rar" => "application/x-rar-compressed",
    "raw" => "image/x-raw",
    "rm" => "application/vnd.rn-realmedia",
    "rmvb" => "application/vnd.rn-realmedia-vbr",
    "rpm" => "audio/x-pn-realaudio-plugin",
    "rsrc" => "application/ResEdit",
    "rtf" => "text/rtf",
    "rv" => "video/vnd.rn-realvideo",
    "rw2" => "image/x-panasonic-rw2",
    "rwl" => "image/x-leica-rwl",
    "rwz" => "image/x-rawzor",
    "seq" => "image/x-flir-seq",
    "sketch" => "application/sketch",
    "sr2" => "image/x-sony-sr2",
    "srf" => "image/x-sony-srf",
    "srw" => "image/x-samsung-srw",
    "svg" => "image/svg+xml",
    "swf" => "application/x-shockwave-flash",
    "tar" => "application/x-tar",
    "thmx" => "application/vnd.ms-officetheme",
    "tif" => "image/tiff",
    "tiff" => "image/tiff",
    "torrent" => "application/x-bittorrent",
    "ttc" => "application/x-font-ttf",
    "ttf" => "application/x-font-ttf",
    "txt" => "text/plain",
    "vcard" => "text/vcard",
    "vrd" => "application/octet-stream",
    "vsd" => "application/x-visio",
    "wav" => "audio/wav",
    "wave" => "audio/wav",
    "wdp" => "image/vnd.ms-photo",
    "webm" => "video/webm",
    "webp" => "image/webp",
    "wma" => "audio/x-ms-wma",
    "wmf" => "application/x-wmf",
    "wmv" => "video/x-ms-wmv",
    "wtv" => "video/x-ms-wtv",
    "x3f" => "image/x-sigma-x3f",
    "xcf" => "image/x-xcf",
    "xla" => "application/vnd.ms-excel",
    "xlam" => "application/vnd.ms-excel.addin.macroEnabled",
    "xls" => "application/vnd.ms-excel",
    "xlsb" => "application/vnd.ms-excel.sheet.binary.macroEnabled",
    "xlsm" => "application/vnd.ms-excel.sheet.macroEnabled",
    "xlsx" => "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet",
    "xlt" => "application/vnd.ms-excel",
    "xltm" => "application/vnd.ms-excel.template.macroEnabled",
    "xltx" => "application/vnd.openxmlformats-officedocument.spreadsheetml.template",
    "xml" => "application/xml",
    "xmp" => "application/rdf+xml",
    "zip" => "application/zip"
  }