237 lines
6.9 KiB
Python
237 lines
6.9 KiB
Python
"""Guess the MIME type of a file.
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This module defines two useful functions:
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guess_type(url) -- guess the MIME type and encoding of a URL.
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guess_extension(type) -- guess the extension for a given MIME type.
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It also contains the following, for tuning the behavior:
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Data:
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knownfiles -- list of files to parse
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inited -- flag set when init() has been called
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suffixes_map -- dictionary mapping suffixes to suffixes
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encodings_map -- dictionary mapping suffixes to encodings
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types_map -- dictionary mapping suffixes to types
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Functions:
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init([files]) -- parse a list of files, default knownfiles
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read_mime_types(file) -- parse one file, return a dictionary or None
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"""
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import string
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import posixpath
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import urllib
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knownfiles = [
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"/usr/local/etc/httpd/conf/mime.types",
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"/usr/local/lib/netscape/mime.types",
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"/usr/local/etc/httpd/conf/mime.types", # Apache 1.2
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"/usr/local/etc/mime.types", # Apache 1.3
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]
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inited = 0
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def guess_type(url):
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"""Guess the type of a file based on its URL.
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Return value is a tuple (type, encoding) where type is None if the
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type can't be guessed (no or unknown suffix) or a string of the
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form type/subtype, usable for a MIME Content-type header; and
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encoding is None for no encoding or the name of the program used
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to encode (e.g. compress or gzip). The mappings are table
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driven. Encoding suffixes are case sensitive; type suffixes are
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first tried case sensitive, then case insensitive.
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The suffixes .tgz, .taz and .tz (case sensitive!) are all mapped
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to ".tar.gz". (This is table-driven too, using the dictionary
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suffix_map).
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"""
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if not inited:
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init()
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scheme, url = urllib.splittype(url)
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if scheme == 'data':
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# syntax of data URLs:
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# dataurl := "data:" [ mediatype ] [ ";base64" ] "," data
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# mediatype := [ type "/" subtype ] *( ";" parameter )
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# data := *urlchar
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# parameter := attribute "=" value
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# type/subtype defaults to "text/plain"
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comma = string.find(url, ',')
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if comma < 0:
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# bad data URL
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return None, None
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semi = string.find(url, ';', 0, comma)
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if semi >= 0:
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type = url[:semi]
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else:
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type = url[:comma]
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if '=' in type or '/' not in type:
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type = 'text/plain'
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return type, None # never compressed, so encoding is None
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base, ext = posixpath.splitext(url)
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while suffix_map.has_key(ext):
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base, ext = posixpath.splitext(base + suffix_map[ext])
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if encodings_map.has_key(ext):
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encoding = encodings_map[ext]
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base, ext = posixpath.splitext(base)
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else:
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encoding = None
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if types_map.has_key(ext):
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return types_map[ext], encoding
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elif types_map.has_key(string.lower(ext)):
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return types_map[string.lower(ext)], encoding
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else:
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return None, encoding
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def guess_extension(type):
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"""Guess the extension for a file based on its MIME type.
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Return value is a string giving a filename extension, including the
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leading dot ('.'). The extension is not guaranteed to have been
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associated with any particular data stream, but would be mapped to the
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MIME type `type' by guess_type(). If no extension can be guessed for
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`type', None is returned.
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"""
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global inited
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if not inited:
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init()
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type = string.lower(type)
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for ext, stype in types_map.items():
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if type == stype:
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return ext
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return None
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def init(files=None):
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global inited
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for file in files or knownfiles:
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s = read_mime_types(file)
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if s:
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for key, value in s.items():
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types_map[key] = value
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inited = 1
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def read_mime_types(file):
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try:
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f = open(file)
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except IOError:
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return None
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map = {}
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while 1:
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line = f.readline()
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if not line: break
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words = string.split(line)
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for i in range(len(words)):
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if words[i][0] == '#':
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del words[i:]
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break
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if not words: continue
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type, suffixes = words[0], words[1:]
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for suff in suffixes:
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map['.'+suff] = type
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f.close()
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return map
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suffix_map = {
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'.tgz': '.tar.gz',
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'.taz': '.tar.gz',
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'.tz': '.tar.gz',
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}
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encodings_map = {
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'.gz': 'gzip',
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'.Z': 'compress',
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}
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types_map = {
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'.a': 'application/octet-stream',
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'.ai': 'application/postscript',
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'.aif': 'audio/x-aiff',
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'.aifc': 'audio/x-aiff',
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'.aiff': 'audio/x-aiff',
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'.au': 'audio/basic',
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'.avi': 'video/x-msvideo',
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'.bcpio': 'application/x-bcpio',
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'.bin': 'application/octet-stream',
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'.cdf': 'application/x-netcdf',
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'.cpio': 'application/x-cpio',
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'.csh': 'application/x-csh',
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'.dll': 'application/octet-stream',
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'.dvi': 'application/x-dvi',
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'.exe': 'application/octet-stream',
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'.eps': 'application/postscript',
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'.etx': 'text/x-setext',
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'.gif': 'image/gif',
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'.gtar': 'application/x-gtar',
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'.hdf': 'application/x-hdf',
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'.htm': 'text/html',
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'.html': 'text/html',
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'.ief': 'image/ief',
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'.jpe': 'image/jpeg',
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'.jpeg': 'image/jpeg',
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'.jpg': 'image/jpeg',
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'.latex': 'application/x-latex',
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'.man': 'application/x-troff-man',
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'.me': 'application/x-troff-me',
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'.mif': 'application/x-mif',
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'.mov': 'video/quicktime',
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'.movie': 'video/x-sgi-movie',
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'.mpe': 'video/mpeg',
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'.mpeg': 'video/mpeg',
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'.mpg': 'video/mpeg',
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'.ms': 'application/x-troff-ms',
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'.nc': 'application/x-netcdf',
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'.o': 'application/octet-stream',
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'.obj': 'application/octet-stream',
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'.oda': 'application/oda',
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'.pbm': 'image/x-portable-bitmap',
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'.pdf': 'application/pdf',
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'.pgm': 'image/x-portable-graymap',
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'.pnm': 'image/x-portable-anymap',
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'.png': 'image/png',
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'.ppm': 'image/x-portable-pixmap',
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'.py': 'text/x-python',
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'.pyc': 'application/x-python-code',
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'.ps': 'application/postscript',
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'.qt': 'video/quicktime',
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'.ras': 'image/x-cmu-raster',
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'.rgb': 'image/x-rgb',
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'.rdf': 'application/xml',
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'.roff': 'application/x-troff',
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'.rtf': 'application/rtf',
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'.rtx': 'text/richtext',
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'.sgm': 'text/x-sgml',
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'.sgml': 'text/x-sgml',
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'.sh': 'application/x-sh',
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'.shar': 'application/x-shar',
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'.snd': 'audio/basic',
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'.so': 'application/octet-stream',
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'.src': 'application/x-wais-source',
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'.sv4cpio': 'application/x-sv4cpio',
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'.sv4crc': 'application/x-sv4crc',
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'.t': 'application/x-troff',
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'.tar': 'application/x-tar',
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'.tcl': 'application/x-tcl',
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'.tex': 'application/x-tex',
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'.texi': 'application/x-texinfo',
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'.texinfo': 'application/x-texinfo',
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'.tif': 'image/tiff',
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'.tiff': 'image/tiff',
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'.tr': 'application/x-troff',
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'.tsv': 'text/tab-separated-values',
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'.txt': 'text/plain',
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'.ustar': 'application/x-ustar',
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'.wav': 'audio/x-wav',
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'.xbm': 'image/x-xbitmap',
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'.xml': 'text/xml',
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'.xsl': 'application/xml',
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'.xpm': 'image/x-xpixmap',
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'.xwd': 'image/x-xwindowdump',
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'.zip': 'application/zip',
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}
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