file_extension_to_mimetype.php

$types = array(
    'ai'      => 'application/postscript',
    'aif'     => 'audio/x-aiff',
    'aifc'    => 'audio/x-aiff',
    'aiff'    => 'audio/x-aiff',
    'asc'     => 'text/plain',
    'atom'    => 'application/atom+xml',
    'atom'    => 'application/atom+xml',
    'au'      => 'audio/basic',
    'avi'     => 'video/x-msvideo',
    'bcpio'   => 'application/x-bcpio',
    'bin'     => 'application/octet-stream',
    'bmp'     => 'image/bmp',
    'cdf'     => 'application/x-netcdf',
    'cgm'     => 'image/cgm',
    'class'   => 'application/octet-stream',
    'cpio'    => 'application/x-cpio',
    'cpt'     => 'application/mac-compactpro',
    'csh'     => 'application/x-csh',
    'css'     => 'text/css',
    'csv'     => 'text/csv',
    'dcr'     => 'application/x-director',
    'dir'     => 'application/x-director',
    'djv'     => 'image/vnd.djvu',
    'djvu'    => 'image/vnd.djvu',
    'dll'     => 'application/octet-stream',
    'dmg'     => 'application/octet-stream',
    'dms'     => 'application/octet-stream',
    'doc'     => 'application/msword',
    'docx'     => 'application/msword',
    'dtd'     => 'application/xml-dtd',
    'dvi'     => 'application/x-dvi',
    'dxr'     => 'application/x-director',
    'eps'     => 'application/postscript',
    'etx'     => 'text/x-setext',
    'exe'     => 'application/octet-stream',
    'ez'      => 'application/andrew-inset',
    'gif'     => 'image/gif',
    'gram'    => 'application/srgs',
    'grxml'   => 'application/srgs+xml',
    'gtar'    => 'application/x-gtar',
    'hdf'     => 'application/x-hdf',
    'hqx'     => 'application/mac-binhex40',
    'htm'     => 'text/html',
    'html'    => 'text/html',
    'ice'     => 'x-conference/x-cooltalk',
    'ico'     => 'image/x-icon',
    'ics'     => 'text/calendar',
    'ief'     => 'image/ief',
    'ifb'     => 'text/calendar',
    'iges'    => 'model/iges',
    'igs'     => 'model/iges',
    'jpe'     => 'image/jpeg',
    'jpeg'    => 'image/jpeg',
    'jpg'     => 'image/jpeg',
    'js'      => 'application/x-javascript',
    'json'    => 'application/json',
    'kar'     => 'audio/midi',
    'latex'   => 'application/x-latex',
    'lha'     => 'application/octet-stream',
    'lzh'     => 'application/octet-stream',
    'm3u'     => 'audio/x-mpegurl',
    'man'     => 'application/x-troff-man',
    'mathml'  => 'application/mathml+xml',
    'me'      => 'application/x-troff-me',
    'mesh'    => 'model/mesh',
    'mid'     => 'audio/midi',
    'midi'    => 'audio/midi',
    'mif'     => 'application/vnd.mif',
    'mov'     => 'video/quicktime',
    'movie'   => 'video/x-sgi-movie',
    'mp2'     => 'audio/mpeg',
    'mp3'     => 'audio/mpeg',
    'mpe'     => 'video/mpeg',
    'mpeg'    => 'video/mpeg',
    'mpg'     => 'video/mpeg',
    'mpga'    => 'audio/mpeg',
    'ms'      => 'application/x-troff-ms',
    'msh'     => 'model/mesh',
    'mxu'     => 'video/vnd.mpegurl',
    'nc'      => 'application/x-netcdf',
    'oda'     => 'application/oda',
    'ogg'     => 'application/ogg',
    'pbm'     => 'image/x-portable-bitmap',
    'pdb'     => 'chemical/x-pdb',
    'pdf'     => 'application/pdf',
    'pgm'     => 'image/x-portable-graymap',
    'pgn'     => 'application/x-chess-pgn',
    'png'     => 'image/png',
    'pnm'     => 'image/x-portable-anymap',
    'ppm'     => 'image/x-portable-pixmap',
    'ppt'     => 'application/vnd.ms-powerpoint',
    'pptx'     => 'application/vnd.ms-powerpoint',
    'ps'      => 'application/postscript',
    'qt'      => 'video/quicktime',
    'ra'      => 'audio/x-pn-realaudio',
    'ram'     => 'audio/x-pn-realaudio',
    'ras'     => 'image/x-cmu-raster',
    'rdf'     => 'application/rdf+xml',
    'rgb'     => 'image/x-rgb',
    'rm'      => 'application/vnd.rn-realmedia',
    'roff'    => 'application/x-troff',
    'rss'     => 'application/rss+xml',
    'rtf'     => 'text/rtf',
    'rtx'     => 'text/richtext',
    'sgm'     => 'text/sgml',
    'sgml'    => 'text/sgml',
    'sh'      => 'application/x-sh',
    'shar'    => 'application/x-shar',
    'silo'    => 'model/mesh',
    'sit'     => 'application/x-stuffit',
    'skd'     => 'application/x-koan',
    'skm'     => 'application/x-koan',
    'skp'     => 'application/x-koan',
    'skt'     => 'application/x-koan',
    'smi'     => 'application/smil',
    'smil'    => 'application/smil',
    'snd'     => 'audio/basic',
    'so'      => 'application/octet-stream',
    'spl'     => 'application/x-futuresplash',
    'src'     => 'application/x-wais-source',
    'sv4cpio' => 'application/x-sv4cpio',
    'sv4crc'  => 'application/x-sv4crc',
    'svg'     => 'image/svg+xml',
    'svgz'    => 'image/svg+xml',
    'swf'     => 'application/x-shockwave-flash',
    't'       => 'application/x-troff',
    'tar'     => 'application/x-tar',
    'tcl'     => 'application/x-tcl',
    'tex'     => 'application/x-tex',
    'texi'    => 'application/x-texinfo',
    'texinfo' => 'application/x-texinfo',
    'tif'     => 'image/tiff',
    'tiff'    => 'image/tiff',
    'tr'      => 'application/x-troff',
    'tsv'     => 'text/tab-separated-values',
    'txt'     => 'text/plain',
    'ustar'   => 'application/x-ustar',
    'vcd'     => 'application/x-cdlink',
    'vrml'    => 'model/vrml',
    'vxml'    => 'application/voicexml+xml',
    'wav'     => 'audio/x-wav',
    'wbmp'    => 'image/vnd.wap.wbmp',
    'wbxml'   => 'application/vnd.wap.wbxml',
    'wml'     => 'text/vnd.wap.wml',
    'wmlc'    => 'application/vnd.wap.wmlc',
    'wmls'    => 'text/vnd.wap.wmlscript',
    'wmlsc'   => 'application/vnd.wap.wmlscriptc',
    'wrl'     => 'model/vrml',
    'xbm'     => 'image/x-xbitmap',
    'xht'     => 'application/xhtml+xml',
    'xhtml'   => 'application/xhtml+xml',
    'xls'     => 'application/vnd.ms-excel',
    'xlsx'     => 'application/vnd.ms-excel',
    'xml'     => 'application/xml',
    'xpm'     => 'image/x-xpixmap',
    'xsl'     => 'application/xml',
    'xslt'    => 'application/xslt+xml',
    'xul'     => 'application/vnd.mozilla.xul+xml',
    'xwd'     => 'image/x-xwindowdump',
    'xyz'     => 'chemical/x-xyz',
    'zip'     => 'application/zip'
  );